{"id":673,"date":"2022-02-21T18:12:34","date_gmt":"2022-02-21T10:12:34","guid":{"rendered":"https:\/\/axinyi.xuenixiang.com\/?p=673"},"modified":"2022-03-09T20:53:35","modified_gmt":"2022-03-09T12:53:35","slug":"javase-4","status":"publish","type":"post","link":"https:\/\/axinyi.xuenixiang.com\/index.php\/2022\/02\/21\/javase-4\/","title":{"rendered":"JavaSE-\u7b2c\u56db\u7ae0"},"content":{"rendered":"\n<p><div class=\"has-toc have-toc\"><\/div><\/p>\n\n\n\n<h1>\u7b2c\u56db\u7ae0 \u9762\u5411\u5bf9\u8c61<\/h1>\n\n\n\n<h2>4.1 \u65b9\u6cd5<\/h2>\n\n\n\n<ul><li>\u65b9\u6cd5\uff1a\u5c31\u662f\u4e00\u79cd\u529f\u80fd\u7684\u4f53\u73b0\u3002\u65b9\u6cd5\u662f\u53ef\u4ee5\u590d\u7528\u7684<\/li><li>\u683c\u5f0f\uff1a<\/li><\/ul>\n\n\n\n<p>\u65b9\u6cd5\u7684\u4fee\u9970\u7b26 \u8fd4\u56de\u7c7b\u578b \u65b9\u6cd5\u540d\u79f0(\u53c2\u6570){<\/p>\n\n\n\n<p>\u65b9\u6cd5\u4f53<\/p>\n\n\n\n<p>}<\/p>\n\n\n\n<ul><li>\u65b9\u6cd5\u7684\u4fee\u9970\u7b26\uff1apublic\u3001private\u3001protected\u3001abstract\u3001static\u3001final...<\/li><li>\u8fd4\u56de\u7c7b\u578b\uff1a\u5982\u679c\u65b9\u6cd5\u6ca1\u6709\u8fd4\u56de\u503c\u90a3\u4e48\u4f7f\u7528void\u4fee\u9970\uff0c\u5982\u679c\u6709\u8fd4\u56de\u7c7b\u578b\u90a3\u4e48\u65b9\u6cd5\u7684\u8fd4\u56de\u503c\u5fc5\u987b\u662f\u8fd9\u79cd\u7c7b\u578b\u3002<\/li><li>\u65b9\u6cd5\u540d\u79f0\uff1a\u7b26\u5408\u6807\u8bc6\u7b26\u5373\u53ef<\/li><li>\u65b9\u6cd5\u7684\u53c2\u6570\uff1a\u53ef\u4ee5\u6ca1\u6709\u6216\u8005\u591a\u4e2a\uff0c\u591a\u4e2a\u4f7f\u7528\u9017\u53f7\u5206\u9694\u7b26<\/li><li>\u6848\u4f8b\uff1a<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args){\n        method();\n    }\n\n    \/\/\u81ea\u5b9a\u4e49\u65b9\u6cd5\n    public static void method(){\n        System.out.println(\"\u8fd9\u662f\u4e00\u4e2a\u6ca1\u6709\u8fd4\u56de\u548c\u53c2\u6570\u7684\u65b9\u6cd5\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u542b\u4e00\u4e2a\u53c2\u6570\u7684\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args){\n        method(1);\n    }\n\n    public static void method(int key){\n        switch(key){\n            case 1:\n                System.out.println(\"\u6267\u884c\u4e86\u7b2c\u4e00\u4e2a\u8bed\u53e5\");\n                break;\n            case 2:\n                System.out.println(\"\u6267\u884c\u4e86\u7b2c\u4e8c\u4e2a\u8bed\u53e5\");\n                break;\n            default:\n                System.out.println(\"\u6267\u884c\u4e86\u5176\u4ed6\u8bed\u53e5\");\n                break;\n        }\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u542b\u4e24\u4e2a\u53c2\u6570\u7684\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args){\n        method(1,2);\n    }\n\n    \/\/\u81ea\u5b9a\u4e49\u65b9\u6cd5\n    public static void method(int m,int n){\n        System.out.println(m+n);\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u542b\u6709\u8fd4\u56de\u503c\u5f97\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args){\n        int sum = method(1,2);\n        System.out.println(sum);\n    }\n\n    \/\/\u81ea\u5b9a\u4e49\u65b9\u6cd5\n    public static int method(int m,int n){\n        return m+n;\n    }\n}<\/code><\/pre>\n\n\n\n<h2>4.2 \u65b9\u6cd5\u7684\u91cd\u8f7d<\/h2>\n\n\n\n<h3>4.2.1 \u91cd\u8f7d\u7684\u6761\u4ef6<\/h3>\n\n\n\n<ul><li>\u5728\u540c\u4e00\u4e2a\u7c7b\u4e2d<\/li><li>\u65b9\u6cd5\u7684\u540d\u79f0\u76f8\u540c\u7684<\/li><li>\u65b9\u6cd5\u7684\u53c2\u6570\u7684\u7c7b\u578b\u3001\u4e2a\u6570\u3001\u987a\u5e8f\u6709\u4e00\u4e2a\u4e0d\u540c\u5373\u53ef<\/li><li>\u4e0e\u65b9\u6cd5\u7684\u8fd4\u56de\u7c7b\u578b\u6ca1\u6709\u5173\u7cfb<\/li><\/ul>\n\n\n\n<h3>4.2.2 \u4e0d\u4f7f\u7528\u91cd\u8f7d<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args){\n        int methodInt = methodInt(1,2);\n    }\n\n    \/\/\u56e0\u4e3a\u6ca1\u6709\u91cd\u8f7d\uff0c\u6240\u4ee5\u589e\u52a0\u4e86\u8bb0\u5fc6\u65b9\u6cd5\u7684\u56f0\u96be\n    public static int methodInt(int m,int n) {\n        return m + n;\n    }\n    public static double methodDouble(double m,int n){\n            return m + n;\n        }\n\n    public static long methodLong(long m,int n){\n        return m+n;\n    }\n}<\/code><\/pre>\n\n\n\n<h3>4.2.3 \u4f7f\u7528\u91cd\u8f7d\uff1a\u51cf\u5c11\u8bb0\u5fc6<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args){\n        sum(1,2);\n    }\n\n\n    public static int sum(int m,int n) {\n        return m + n;\n    }\n    public static double sum(double m,int n){\n            return m + n;\n        }\n\n    public static long sum(long m,int n){\n        return m+n;\n    }\n}<\/code><\/pre>\n\n\n\n<h3>4.2.4 \u91cd\u8f7d\u7684\u6761\u4ef6<\/h3>\n\n\n\n<ul><li>\u53c2\u6570\u7684\u7c7b\u578b\u4e0d\u80fd\u76f8\u540c<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-39.png\" alt=\"\" class=\"wp-image-684\" width=\"841\" height=\"294\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-39.png 604w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-39-300x105.png 300w\" sizes=\"(max-width: 841px) 100vw, 841px\" \/><\/figure>\n\n\n\n<ul><li>\u53c2\u6570\u7684\u4e2a\u6570\u4e0d\u80fd\u76f8\u540c<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-40.png\" alt=\"\" class=\"wp-image-685\" width=\"839\" height=\"274\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-40.png 671w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-40-300x98.png 300w\" sizes=\"(max-width: 839px) 100vw, 839px\" \/><\/figure>\n\n\n\n<ul><li>\u53c2\u6570\u7684\u7c7b\u578b\u987a\u5e8f\u4e0d\u80fd\u76f8\u540c<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-41.png\" alt=\"\" class=\"wp-image-686\" width=\"840\" height=\"287\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-41.png 612w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-41-300x102.png 300w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><\/figure>\n\n\n\n<h2>4.3 \u9012\u5f52<\/h2>\n\n\n\n<h3>4.3.1 \u6848\u4f8b\uff1a\u6c4210\u4ee5\u5185\u7684\u548c<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args){\n        int sum = 0;\n        for (int i = 0; i &lt; 6; i++) {\n            sum += i;\n        }\n        System.out.println(sum);\n    }\n}<\/code><\/pre>\n\n\n\n<h3>4.3.2 \u6848\u4f8b\uff1a\u4f7f\u7528\u9012\u5f52<\/h3>\n\n\n\n<ul><li>\u81ea\u8eab\u7684\u8c03\u7528\uff1b\u5c31\u662f\u81ea\u5df1\u8c03\u7528\u81ea\u5df1<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args){\n        int sum = rec(5);\n        System.out.println(sum);\n    }\n    \/\/\u9012\u5f52\n    public static int rec(int i){\n        if(i==1)\n            return 1;\n        return i+rec(i-1);\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u8be6\u89e3<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args){\n        int sum = rec(5);\n        System.out.println(sum);\n    }\n    \/\/\u9012\u5f52\n\n    \/**\n     * \u8fd4\u56de\uff1a5+4+3+2+1\n     5+rec(5-1)\n     4+rec(4-1)\n     3+rec(3-1)\n     2+rec(2-1)\n     1\n     *\/\n    public static int rec(int i){\n        if(i==1)\n            return 1;\n        return i+rec(i-1);\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>n\u7684\u9636\u5c42<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public static int rec(int n){\n    if(n==1)\n        return 1;\n    return n*rec(n-1);\n}<\/code><\/pre>\n\n\n\n<h2>4.4 \u4f7f\u7528\u65b9\u6cd5\u5b8c\u6210\u9879\u76ee<\/h2>\n\n\n\n<h3>4.4.1 \u7b2c\u4e00\u7248<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>import java.util.Scanner;\npublic class Demo {\n    public static void main(String&#91;] args){\n        \/\/\u63a7\u5236\u53f0\u5bf9\u8c61\n        Scanner scanner = new Scanner(System.in);\n        \/\/\u8df3\u51fa\u5faa\u73af\u7684\u6807\u8bc6\n        boolean flag = true;\n        \/\/\u63d0\u793a\u4fe1\u606f\n        System.out.println(\"1\u6dfb\u52a0\uff1b2\u663e\u793a\uff1b3\u5220\u9664\uff1b4\u66f4\u65b0\uff1b5\u9000\u51fa\uff1b\");\n        \/\/\u5faa\u73af\n        do {\n            int key = scanner.nextInt();\n            switch (key){\n                case 1:\n                    System.out.println(\"\u8bf7\u8f93\u5165\u4e00\u4e2a\u6570\u5b57\");\n                    save(scanner.nextInt());\n                    break;\n                case 2:\n                    findAll();\n                    break;\n                case 3:\n                    System.out.println(\"\u8bf7\u8f93\u5165\u4e00\u4e2a\u9700\u8981\u5220\u9664\u7684\u6570\u5b57\");\n                    delete(scanner.nextInt());\n                    break;\n                case 4:\n                    System.out.println(\"\u8bf7\u8f93\u5165\u9700\u8981\u66f4\u65b0\u7684\u6570\u5b57\");\n                    int i = scanner.nextInt();\n                    System.out.println(\"\u8bf7\u8f93\u5165\u9700\u8981\u66f4\u65b0\u7684\u65b0\u6570\u5b57\");\n                    int n = scanner.nextInt();\n                    update(i,n);\n                    break;\n                case 5:\n                    flag = false;\n                    break;\n            }\n        }while(flag);\n    }\n    \/\/\u521b\u5efa\u6570\u7ec4\n    static int&#91;] array = new int&#91;3];\n\n    \/\/\u83b7\u53d6\u6570\u636e\u7684\u4e0b\u6807\n    public static int findByIndex(int element){\n        \/\/\u901a\u8fc7\u5224\u65adelement\u7684\u503c\u51b3\u5b9a\u67e5\u627e\u7a7a\u4f4d\u7f6e\u8fd8\u662f\u5bf9\u5e94\u5143\u7d20\u7684\u4e0b\u6807\n        for (int index = 0; index &lt; array.length; index++) {\n            if (element == 0) {\/\/\u83b7\u53d6\u7a7a\u4f4d\u7f6e\n                if (array&#91;index] == 0) {\n                    return index;\n                }\n            } else {\/\/\u67e5\u8be2\u5bf9\u5e94\u5143\u7d20\u7684\u4e0b\u6807\n                if (array&#91;index] == element) {\n                    return index;\n                }\n            }\n        }\n        return -1;\n    }\n\n    \/\/\u6dfb\u52a0\u6570\u636e\n    public static void save(int el){\n            \/\/\u83b7\u53d6\u4e00\u4e2a\u4fdd\u5b58\u5143\u7d20\u7684\u7a7a\u4f4d\u7f6e\n            int index = findByIndex(0);\n            \/\/\u5224\u65ad\u4e0b\u6807\n            if (index!=-1){\n                array&#91;index] = el;\n                System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n            }else{\n                System.out.println(\"full\");\n            }\n        }\n\n    \/\/\u663e\u793a\u6570\u636e\n    public static void findAll(){\n            for (int index = 0; index &lt; array.length; index++) {\n                int i = array&#91;index];\n                if (i!=0) {\n                    System.out.println(i);\n                }\n            }\n        }\n\n    \/\/\u5220\u9664\u6570\u636e\n    public static void delete(int el){\n            \/\/\u6839\u636e\u5143\u7d20\u83b7\u53d6\u4e0b\u6807\n            int index = findByIndex(el);\n            \/\/\u5224\u65ad\n            if (index!=-1){\n                array&#91;index] = 0;\n                System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n            }else {\n                System.out.println(\"\u67e5\u65e0\u6b64\u6570\u636e\uff0c\u8bf7\u91cd\u65b0\u8f93\u5165\");\n            }\n        }\n\n    \/\/\u66f4\u65b0\u6570\u636e\n    public static void update(int el,int target){\n            \/\/\u6839\u636e\u5143\u7ec4\u83b7\u53d6\u4e0b\u6807\n            int index = findByIndex(el);\n            \/\/\u5224\u65ad\n            if (index!=-1) {\n                array&#91;index] = target;\n                System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n            }else{\n                System.out.println(\"\u67e5\u65e0\u6b64\u6570\u636e\u8bf7\u91cd\u65b0\u8f93\u5165\");\n            }\n        }\n}<\/code><\/pre>\n\n\n\n<h3>4.4.2 \u7b2c\u4e8c\u7248<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>import java.util.Scanner;\npublic class Demo {\n    public static void main(String&#91;] args){\n        \/\/\u63a7\u5236\u53f0\u5bf9\u8c61\n        Scanner scanner = new Scanner(System.in);\n        \/\/\u8df3\u51fa\u5faa\u73af\u7684\u6807\u8bc6\n        boolean flag = true;\n        \/\/\u63d0\u793a\u4fe1\u606f\n        System.out.println(\"1\u6dfb\u52a0\uff1b2\u663e\u793a\uff1b3\u5220\u9664\uff1b4\u66f4\u65b0\uff1b5\u9000\u51fa\uff1b\");\n        \/\/\u5faa\u73af\n        do {\n            int key = scanner.nextInt();\n            switch (key){\n                case 1:\n                    save(scanner);\n                    break;\n                case 2:\n                    findAll();\n                    break;\n                case 3:\n                    delete(scanner);\n                    break;\n                case 4:\n                    update(scanner);\n                    break;\n                case 5:\n                    flag = false;\n                    break;\n            }\n        }while(flag);\n    }\n    \/\/\u521b\u5efa\u6570\u7ec4\n    static int&#91;] array = new int&#91;3];\n\n    \/\/\u83b7\u53d6\u6570\u636e\u7684\u4e0b\u6807\n    public static int findByIndex(int element){\n        \/\/\u901a\u8fc7\u5224\u65adelement\u7684\u503c\u51b3\u5b9a\u67e5\u627e\u7a7a\u4f4d\u7f6e\u8fd8\u662f\u5bf9\u5e94\u5143\u7d20\u7684\u4e0b\u6807\n        for (int index = 0; index &lt; array.length; index++) {\n            if (element == 0) {\/\/\u83b7\u53d6\u7a7a\u4f4d\u7f6e\n                if (array&#91;index] == 0) {\n                    return index;\n                }\n            } else {\/\/\u67e5\u8be2\u5bf9\u5e94\u5143\u7d20\u7684\u4e0b\u6807\n                if (array&#91;index] == element) {\n                    return index;\n                }\n            }\n        }\n        return -1;\n    }\n\n    \/\/\u6dfb\u52a0\u6570\u636e\n    public static void save(Scanner scanner){\n            \/\/\u83b7\u53d6\u4e00\u4e2a\u4fdd\u5b58\u5143\u7d20\u7684\u7a7a\u4f4d\u7f6e\n            int index = findByIndex(0);\n            \/\/\u5224\u65ad\u4e0b\u6807\n            if (index!=-1){\n                System.out.println(\"\u8bf7\u8f93\u5165\u4e00\u4e2a\u6570\u5b57\");\n                array&#91;index] = scanner.nextInt();\n                System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n            }else{\n                System.out.println(\"full\");\n            }\n        }\n\n    \/\/\u663e\u793a\u6570\u636e\n    public static void findAll(){\n            for (int index = 0; index &lt; array.length; index++) {\n                int i = array&#91;index];\n                if (i!=0) {\n                    System.out.println(i);\n                }\n            }\n        }\n\n    \/\/\u5220\u9664\u6570\u636e\n    public static void delete(Scanner scanner){\n        System.out.println(\"\u8bf7\u8f93\u5165\u4e00\u4e2a\u9700\u8981\u5220\u9664\u7684\u6570\u5b57\");\n        \/\/\u6839\u636e\u5143\u7d20\u83b7\u53d6\u4e0b\u6807\n        int index = findByIndex(scanner.nextInt());\n        \/\/\u5224\u65ad\n        if (index!=-1){\n            array&#91;index] = 0;\n            System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n        }else {\n            System.out.println(\"\u67e5\u65e0\u6b64\u6570\u636e\uff0c\u8bf7\u91cd\u65b0\u8f93\u5165\");\n        }\n    }\n\n    \/\/\u66f4\u65b0\u6570\u636e\n    public static void update(Scanner scanner){\n        System.out.println(\"\u8bf7\u8f93\u5165\u9700\u8981\u66f4\u65b0\u7684\u6570\u5b57\");\n            \/\/\u6839\u636e\u5143\u7ec4\u83b7\u53d6\u4e0b\u6807\n            int index = findByIndex(scanner.nextInt());\n            \/\/\u5224\u65ad\n            if (index!=-1) {\n                System.out.println(\"\u8bf7\u8f93\u5165\u9700\u8981\u66f4\u65b0\u7684\u65b0\u6570\u5b57\");\n                array&#91;index] = scanner.nextInt();\n                System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n            }else{\n                System.out.println(\"\u67e5\u65e0\u6b64\u6570\u636e\u8bf7\u91cd\u65b0\u8f93\u5165\");\n            }\n        }\n}<\/code><\/pre>\n\n\n\n<h2>4.5 \u9762\u5411\u8fc7\u7a0b\u533a\u522b\u9762\u5411\u5bf9\u8c61<\/h2>\n\n\n\n<ul><li>c\u8bed\u8a00\u5c31\u662f\u9762\u5411\u8fc7\u7a0b\u8bed\u8a00<\/li><li>\u9762\u5411\u8fc7\u7a0b\u7684\u7279\u70b9\uff1a\u5fc5\u987b\u4e86\u89e3\u6574\u4e2a\u8fc7\u7a0b\uff0c\u6bcf\u4e2a\u6b65\u9aa4\u7684\u56e0\u679c\u5173\u7cfb<\/li><li>\u9762\u5411\u5bf9\u8c61\uff1a\u5c06\u73b0\u5b9e\u4e16\u754c\u5206\u4e3a\u4e0d\u540c\u7684\u5bf9\u8c61\uff0c\u628a\u5404\u4e2a\u5bf9\u8c61\u534f\u4f5c\u8d77\u6765<ul><li>\u5c31\u662f\u9762\u5bf9\u4e00\u4e2a\u771f\u5b9e\u5b58\u5728\u7684<\/li><li>\u9762\u5411\u5bf9\u8c61\u7684\u7279\u6027\uff1a\u5b9e\u8d28\u5c31\u662f\u9762\u5411\u62bd\u8c61<ul><li>\u62bd\u8c61\uff1a\u5177\u6709\u8fd9\u4e00\u7c7b\u4e8b\u52a1\u7684\u7279\u5f81\u548c\u7279\u6027<\/li><li>\u9762\u5411\u5bf9\u8c61\u7b26\u5408\u4eba\u7684\u601d\u7ef4<\/li><\/ul><\/li><\/ul><\/li><\/ul>\n\n\n\n<h3>4.5.1 \u9762\u5411\u5bf9\u8c61\u7684\u7279\u6027<\/h3>\n\n\n\n<ul><li>\u5c01\u88c5<\/li><li>\u7ee7\u627f<\/li><li>\u591a\u6001<\/li><\/ul>\n\n\n\n<h3>4.5.2 \u7c7b\u4e0e\u5bf9\u8c61\u7684\u6982\u5ff5<\/h3>\n\n\n\n<ul><li>\u7c7b\uff1a\u5bf9\u5177\u6709\u5171\u6027\u4e8b\u7269\u7684\u62bd\u8c61\u63cf\u8ff0<ul><li>\u4f8b\u5982\uff1a\u5b66\u751f\u7c7b=\u5b66\u53f7\u3001\u59d3\u540d\u3001\u6027\u522b\u3001\u5e74\u9f84\u3001\u73ed\u7ea7<\/li><\/ul><\/li><li>\u5bf9\u8c61(\u5b9e\u4f8b)\uff1a\u5c31\u662f\u5bf9\u7c7b\u7684\u5177\u4f53\u5316\u3001\u5b9e\u4f8b\u5316<ul><li>\u4f8b\u5982\uff1a\u5b66\u751f\u5bf9\u8c61\uff1a1001\u3001\u5c0f\u7070\u7070\u3001\u7537\u30016\u30013\u73ed<\/li><\/ul><\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-42.png\" alt=\"\" class=\"wp-image-687\" width=\"838\" height=\"630\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-42.png 511w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-42-300x225.png 300w\" sizes=\"(max-width: 838px) 100vw, 838px\" \/><\/figure>\n\n\n\n<ul><li>\u4ee5\u4e0a\u7684\u7c7b\u56fe\u4e2d\u90fd\u662f\u5c5e\u6027\uff0c\u8fdb\u4e00\u6b65\u7ec6\u5316\uff0c\u6dfb\u52a0\u7c7b\u4e2d\u7684\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-43.png\" alt=\"\" class=\"wp-image-688\" width=\"838\" height=\"810\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-43.png 597w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-43-300x290.png 300w\" sizes=\"(max-width: 838px) 100vw, 838px\" \/><\/figure>\n\n\n\n<ul><li>\u7ed3\u8bba\uff1a\u5c5e\u6027\u6e90\u81ea\u4e8e\u4e00\u79cd\u72b6\u6001\uff0c\u65b9\u6cd5\u6e90\u81ea\u4e8e\u4e00\u4e2a\u529f\u80fd(\u52a8\u4f5c)<ul><li>\u7c7b=\u5c5e\u6027+\u65b9\u6cd5<\/li><li>\u7c7b=\u6210\u5458+\u529f\u80fd<\/li><\/ul><\/li><\/ul>\n\n\n\n<h3>4.5.3 \u7c7b\u7684\u5b9a\u4e49<\/h3>\n\n\n\n<p>\u683c\u5f0f\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u7c7b\u7684\u4fee\u9970\u7b26 class \u7c7b\u540d\u79f0 extends \u7236\u7c7b\u540d\u79f0 implements \u63a5\u53e3\u540d\u79f0{\n    \u7c7b\u4f53\uff1a\u5c5e\u6027+\u65b9\u6cd5\n}<\/code><\/pre>\n\n\n\n<ul><li>\u6848\u4f8b\uff1a\u521b\u5efa\u7c7b<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Student {\n    \/\/\u5b66\u53f7\n    int id;\n    \/\/\u59d3\u540d\n    String name;\n    \/\/\u6027\u522b\n    String sex;\n    \/\/\u5730\u5740\n    String address;\n    \/\/\u5e74\u9f84\n    int age;\n}<\/code><\/pre>\n\n\n\n<ul><li>\u4ee5\u4e0a\u90fd\u662f\u5c5e\u6027\uff0c\u4e5f\u6210\u4e3a\u6210\u5458\u53d8\u91cf<\/li><li>\u6210\u5458\u53d8\u91cf\u4f1a\u9ed8\u8ba4\u521d\u59cb\u5316<\/li><li><strong>\u6ce8\u610f\uff1a\u5c40\u90e8\u53d8\u91cf\u4e0d\u80fd\u9ed8\u8ba4\u521d\u59cb\u5316\uff0c\u5fc5\u987b\u521d\u59cb\u5316<\/strong><\/li><\/ul>\n\n\n\n<h3>4.5.4 \u5bf9\u8c61\u7684\u521b\u5efa\u548c\u4f7f\u7528<\/h3>\n\n\n\n<ul><li>\u4f7f\u7528<strong>new<\/strong>\u5173\u952e\u5b57\u521b\u5efa\u5bf9\u8c61\uff0c\u624d\u53ef\u4ee5\u4f7f\u7528<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class TestDemo {\n    public static void main(String&#91;] args) {\n        \/\/\u521b\u5efa\u5bf9\u8c61:\u628a\u5806\u5185\u5b58\u4e2d\u8fd9\u4e2a\u5bf9\u8c61\u7684\u5185\u5b58\u5730\u5740\u8d4b\u503c\u7ed9\u53c2\u6570student\u4e86\n        Student student = new Student();\n        System.out.println(\"\u5185\u5b58\u5730\u5740:\"+student);\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u5c5e\u6027\u9ed8\u8ba4\u503c<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"1024\" height=\"285\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-44-1024x285.png\" alt=\"\" class=\"wp-image-689\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-44-1024x285.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-44-300x84.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-44-768x214.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-44.png 1465w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<ul><li>\u521b\u5efa\u6d41\u7a0b\u56fe<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"1024\" height=\"596\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-45-1024x596.png\" alt=\"\" class=\"wp-image-690\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-45-1024x596.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-45-300x175.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-45-768x447.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-45.png 1109w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<ul><li>\u5177\u4f53\u7684\u9ed8\u8ba4\u503c<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-table is-style-stripes\"><table><thead><tr><th>\u7c7b\u578b<\/th><th>\u9ed8\u8ba4\u503c<\/th><\/tr><\/thead><tbody><tr><td>byte<\/td><td>0<\/td><\/tr><tr><td>short<\/td><td>0<\/td><\/tr><tr><td>int<\/td><td>0<\/td><\/tr><tr><td>long<\/td><td>0<\/td><\/tr><tr><td>float<\/td><td>0.0<\/td><\/tr><tr><td>double<\/td><td>0.0<\/td><\/tr><tr><td>boolean<\/td><td>false<\/td><\/tr><tr><td>char<\/td><td>''<\/td><\/tr><tr><td>\u5f15\u7528\u7c7b\u578b<\/td><td>null<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"1024\" height=\"374\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-46-1024x374.png\" alt=\"\" class=\"wp-image-691\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-46-1024x374.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-46-300x110.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-46-768x280.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-46.png 1271w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h4>4.5.4.1 \u53ef\u4ee5\u5bf9\u6210\u5458\u53d8\u91cf\u8fdb\u884c\u8d4b\u503c<\/h4>\n\n\n\n<ul><li>\u5c31\u662f\u628a\u9ed8\u8ba4\u503c\u66ff\u6362\u4e86<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"1024\" height=\"468\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-47-1024x468.png\" alt=\"\" class=\"wp-image-692\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-47-1024x468.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-47-300x137.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-47-768x351.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-47.png 1427w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<ul><li>\u4e00\u4e2a\u7c7b\u53ef\u4ee5\u521b\u5efaN\u4e2a\u5bf9\u8c61\uff0c\u5e76\u4e14\uff0c\u6bcf\u4e2a\u5bf9\u8c61\u7684\u6210\u5458\u503c\u5c5e\u4e8e\u5f53\u524d\u5bf9\u8c61;<\/li><li>\u53ea\u6709\u901a\u8fc7\u5bf9\u8c61\u624d\u53ef\u4ee5\u4fee\u6539\u6216\u8005\u8bbf\u95ee\u8fd9\u4e2a\u5bf9\u8c61\u7684\u6210\u5458(\u5c5e\u6027)\uff1b<\/li><\/ul>\n\n\n\n<h2>4.6 \u5c01\u88c5\u6027<\/h2>\n\n\n\n<ul><li>\u5c5e\u6027\u79c1\u6709\u5316\uff0c\u7ec6\u8282\u88ab\u9690\u85cf\u6389\uff0c\u5b89\u5168\u6027\u63d0\u9ad8\u4e86\u3002<\/li><li>private\u5173\u952e\u5b57\u4f5c\u7528\u5c31\u662f\u628a\u5c5e\u6027\u4fdd\u62a4\u8d77\u6765\u4e86\u3002<ul><li>\u5728\u672c\u7c7b\u4e2d\u53ef\u4ee5\u8bbf\u95ee<\/li><li>\u5c31\u53ea\u80fd\u81ea\u5df1\u4f7f\u7528<\/li><li>\u5c31\u662f\u4e3a\u4e86\u5b89\u5168\uff0c\u5916\u754c\u65e0\u6cd5\u8bbf\u95ee<\/li><\/ul><\/li><\/ul>\n\n\n\n<h3>4.6.1 \u6dfb\u52a0\u4e00\u4e2a\u65b9\u6cd5\u5b8c\u6210\u5bf9\u6210\u5458(\u5c5e\u6027)\u7684\u64cd\u4f5c<\/h3>\n\n\n\n<ul><li>\u6dfb\u52a0\u65b9\u6cd5(\u529f\u80fd)\u7684\u76ee\u7684\uff0c\u5c31\u662f\u5728\u4f7f\u7528\u7684\u65f6\u5019\u53ef\u4ee5\u6dfb\u52a0\u5404\u79cd\u9650\u5236(\u6761\u4ef6\uff0c\u6dfb\u52a0\u5224\u65ad)\uff1b<\/li><li>\u65b9\u6cd5\u5c31\u662f\u5bf9\u6210\u5458\u64cd\u4f5c\u7684<\/li><li>\u6848\u4f8b<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class TestDemo {\n    public static void main(String&#91;] args) {\n        Student student = new Student();\n        \/\/\u901a\u8fc7\u65b9\u6cd5\u628a\u5916\u9762\u7684\u6570\u636e\u6dfb\u52a0\u5230\u5bf9\u8c61\u4e2d\u7684\u6210\u5458\u4e0a\n        student.setAge(20);\n        \/\/\u901a\u8fc7\u65b9\u6cd5\u628a\u6210\u5458\u7684\u6570\u636e\u83b7\u53d6\n        int age = student.getAge();\n        System.out.println(age);\n        \n    }\n}\n\nclass Student {\n    \/\/\u5b66\u53f7\n    private int id;\n    \/\/\u59d3\u540d\n    private String name;\n    \/\/\u6027\u522b\n    private String sex;\n    \/\/\u5730\u5740\n    private String address;\n    \/\/\u5e74\u9f84\n    private int age;\n\n    \/\/\u6dfb\u52a0\u5e74\u9f84\n    public void setAge(int nl) {\n        if (nl &gt; 0 &amp; nl &lt; 300) {\n            age = nl;\n        } else {\n            System.out.println(\"\u8bf7\u6dfb\u52a0\u8303\u56f4\u5185\u7684\u6570\u5b57\");\n        }\n    }\n    \/\/\u83b7\u53d6\u5e74\u9f84\n    public int getAge() {\n        return age;\n    }\n}<\/code><\/pre>\n\n\n\n<p><strong>\u901a\u8fc7\u4e0a\u9762\u7684\u6848\u4f8b\uff0c\u907f\u514d\u4e86\u76f4\u63a5\u64cd\u4f5c\u5bf9\u8c61\u7684\u5c5e\u6027\uff0c\u8fd9\u5c31\u662f\u5c01\u88c5\uff1b\u8ba9\u5916\u754c\u5bf9\u7c7b\u5185\u90e8\u77e5\u9053\u7684\u8d8a\u5c11\u8d8a\u597d\uff1b<\/strong><\/p>\n\n\n\n<p><strong>\u7ed3\u8bba\uff1a\u5c01\u88c5\u5c5e\u6027\uff1b\u66b4\u9732\u65b9\u6cd5<\/strong><\/p>\n\n\n\n<h2>4.7 \u6784\u9020\u65b9\u6cd5\uff08\u6784\u9020\u5668\u3001\u6784\u9020\u51fd\u6570\uff09<\/h2>\n\n\n\n<ul><li>\u6784\u9020\u65b9\u6cd5\u5c31\u662f\u521b\u5efa\u5bf9\u8c61\u7684<\/li><\/ul>\n\n\n\n<h3>4.7.1 \u683c\u5f0f\uff1a<\/h3>\n\n\n\n<ul><li>\u6784\u9020\u65b9\u6cd5\u7684\u4fee\u9970\u7b26\uff1aprivate public protected<\/li><li>\u6784\u9020\u65b9\u6cd5\u548c\u666e\u901a\u65b9\u6cd5\u4e00\u6837\u90fd\u53ef\u4ee5\u8fdb\u884c\u91cd\u8f7d<\/li><li>\u6784\u9020\u65b9\u6cd5\u7279\u70b9\uff1a<ul><li>\u4e0e\u7c7b\u540c\u540d<\/li><li>\u6784\u9020\u65b9\u6cd5\u4e0d\u80fd\u6709\u4efb\u4f55\u8fd4\u56de\u7c7b\u578b\uff0c\u5373\u6ca1\u6709\u8fd4\u56de\u503c\uff0c\u5173\u952e\u5b57void\u4e5f\u4e0d\u80fd\u52a0\uff1b\u5982\u679c\u6dfb\u52a0\u4e86void\u90a3\u4e48\u5c31\u4e0d\u662f\u6784\u9020\u65b9\u6cd5\u4e86\uff0c\u800c\u662f\u666e\u901a\u65b9\u6cd5\u3002<\/li><li>\u4efb\u4f55\u7c7b\u90fd\u6709\u6784\u9020\u65b9\u6cd5\uff0c\u5982\u679c\u6ca1\u6709\u663e\u793a\u7684\u7f16\u5199\uff0c\u5728\u521b\u5efa\u5bf9\u8c61\u65f6\uff0c\u7cfb\u7edf\u4f1a\u5206\u914d\u4e00\u4e2a\u9ed8\u8ba4\u7684\u65e0\u53c2\u6570\u6784\u9020\u65b9\u6cd5\uff1b\u5982\u679c\u663e\u793a\u7684\u5b9a\u4e49\u4e86\u6784\u9020\u65b9\u6cd5\uff0c\u7cfb\u7edf\u5c31\u4e0d\u4f1a\u521b\u5efa\u9ed8\u8ba4\u7684\u65e0\u53c2\u6570\u6784\u9020\u65b9\u6cd5\u4e86\u3002<\/li><\/ul><\/li><\/ul>\n\n\n\n<ul><li>4.7.2 \u6848\u4f8b\uff1a\u65e0\u53c2\u6784\u9020\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class TestDemo {\n    public static void main(String&#91;] args) {\n        Student student = new Student();\n    }\n}\n\nclass Student {\n    \/\/\u7cfb\u7edf\u9ed8\u8ba4\u5206\u914d\u4e86\u4e00\u4e2a\u65e0\u53c2\u6570\u7684\u6784\u9020\u65b9\u6cd5\n}<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>public class TestDemo {\n    public static void main(String&#91;] args) {\n        Student student = new Student();\n    }\n}\n\nclass Student {\n    \/\/\u65e0\u53c2\u6570\u6784\u9020\u65b9\u6cd5\n    public Student(){\n        System.out.println(\"\u65e0\u53c2\u6570\u6784\u9020\u65b9\u6cd5\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u6dfb\u52a0void\u90a3\u4e48\u5c31\u53d8\u4e3a\u666e\u901a\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>class Student {\n    \/\/\u521b\u5efa\u4e86\u4e00\u4e2a\u666e\u901a\u65b9\u6cd5\n    public void Student(){\n        System.out.println(\"\u521b\u5efa\u4e86\u4e00\u4e2a\u666e\u901a\u65b9\u6cd5\");\n    }\n}<\/code><\/pre>\n\n\n\n<h3>4.7.3 \u663e\u793a\u7f16\u5199\u6784\u9020\u65b9\u6cd5<\/h3>\n\n\n\n<ul><li>\u521b\u5efa\u5bf9\u8c61\u65f6\uff0c\u7cfb\u7edf\u4e0d\u4f1a\u5728\u5206\u914d\u9ed8\u8ba4\u7684\u6784\u9020\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class TestDemo {\n    public static void main(String&#91;] args) {\n        Student student = new Student();\n    }\n}\n\nclass Student {\n    \/\/\u6784\u9020\u65b9\u6cd5\u91cd\u8f7d\n    \n    \/\/\u65e0\u53c2\u6570\u6784\u9020\u65b9\u6cd5\n    public Student(){\n        System.out.println(\"\u65e0\u53c2\u6570\u6784\u9020\u65b9\u6cd5\");\n    }\n    \/\/\u6709\u53c2\u6570\u6784\u9020\u65b9\u6cd5\n    public Student(int i){\n        System.out.println(\"\u6709\u53c2\u6570\u6784\u9020\u65b9\u6cd5\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u521d\u59cb\u5316<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class TestDemo {\n    public static void main(String&#91;] args) {\n        Student student = new Student(1001, \"\u5f20\u4e09\", \"\u7537\");\n    }\n}<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"1024\" height=\"418\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-48-1024x418.png\" alt=\"\" class=\"wp-image-693\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-48-1024x418.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-48-300x122.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-48-768x313.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-48.png 1451w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h2>4.8 \u5bf9\u8c61\u548c\u5f15\u7528<\/h2>\n\n\n\n<h3>4.8.1 java\u5185\u5b58\u7684\u4e3b\u8981\u5212\u5206<\/h3>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" width=\"820\" height=\"571\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-49.png\" alt=\"\" class=\"wp-image-694\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-49.png 820w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-49-300x209.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-49-768x535.png 768w\" sizes=\"(max-width: 820px) 100vw, 820px\" \/><\/figure>\n\n\n\n<h3>4.8.2 \u5185\u5b58\u7684\u8868\u793a<\/h3>\n\n\n\n<ul><li>\u4e3b\u65b9\u6cd5main\u538b\u5165\u6808\uff0c\u5c31\u521b\u5efa\u4e00\u4e2astudent\u5bf9\u8c61<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class TestDemo {\n    public static void main(String&#91;] args) {\n        Student student = new Student(1001, \"\u5f20\u4e09\", \"\u7537\");\n    }\n}<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" width=\"921\" height=\"480\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-50.png\" alt=\"\" class=\"wp-image-695\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-50.png 921w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-50-300x156.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-50-768x400.png 768w\" sizes=\"(max-width: 921px) 100vw, 921px\" \/><\/figure>\n\n\n\n<ul><li>\u5bf9student\u8fd9\u4e2a\u5bf9\u8c61\u4e2d\u7684\u6210\u5458\u8d4b\u503c<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class TestDemo {\n    public static void main(String&#91;] args) {\n        Student student = new Student(1001, \"\u5f20\u4e09\", \"\u7537\");\n    }\n}\n\nclass Student {\n    \/\/\u5b66\u53f7\n    private int id;\n    \/\/\u59d3\u540d\n    private String name;\n    \/\/\u6027\u522b\n    private String sex;\n\n    public Student(int i,String username,String xb){\n        id = i;\n        name = username;\n        sex = xb;\n    }\n}<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-51.png\" alt=\"\" class=\"wp-image-696\" width=\"841\" height=\"687\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-51.png 591w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-51-300x245.png 300w\" sizes=\"(max-width: 841px) 100vw, 841px\" \/><\/figure>\n\n\n\n<h3>4.8.3 \u5f53\u4e0d\u4f7f\u7528new\u5173\u952e\u5b57\u65f6\uff0c\u51fa\u73b0\u95ee\u9898<\/h3>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-52.png\" alt=\"\" class=\"wp-image-697\" width=\"842\" height=\"561\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-52.png 575w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-52-300x200.png 300w\" sizes=\"(max-width: 842px) 100vw, 842px\" \/><\/figure>\n\n\n\n<h2>4.9 this\u5173\u952e\u5b57<\/h2>\n\n\n\n<ul><li>this\u8868\u793a\u5f53\u524d\u5bf9\u8c61<\/li><li>\u5982\u679c\u5806\u4e2d\u6709n\u4e2a\u5bf9\u8c61\uff0c\u4f1a\u6709n\u4e2athis\u6307\u5411\u5bf9\u5e94\u7684\u5bf9\u8c61<\/li><\/ul>\n\n\n\n<h3>4.9.1 \u5c40\u90e8\u53d8\u91cf<\/h3>\n\n\n\n<ul><li>\u5f53\u5c40\u90e8\u53d8\u91cf\u4e0e\u6210\u5458\u53d8\u91cf\u540d\u79f0\u76f8\u540c\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528this\u52a0\u4ee5\u533a\u5206\uff0c\u56e0\u4e3a\u5c31\u8fd1\u539f\u5219<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class TestDemo {\n    public static void main(String&#91;] args) {\n        Student student = new Student();\n        student.setName(\"\u5f20\u4e09\");\n    }\n}\n\nclass Student {\n    \n    \/\/\u59d3\u540d\n    private String name;\n\n    public void Student(String name){\n        \/\/\u5c31\u628aname\u53c2\u6570\u7684\u6570\u503c\u8d4b\u503c\u7ed9\u5f53\u524d\u5bf9\u8c61\u7684\u6210\u5458\u53d8\u91cf\u4e86\n        this.name = name;\n    }\n} <\/code><\/pre>\n\n\n\n<ul><li>\u81ea\u52a8\u751f\u6210setter\u548cgetter\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-53.png\" alt=\"\" class=\"wp-image-698\" width=\"523\" height=\"390\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-53.png 303w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-53-300x224.png 300w\" sizes=\"(max-width: 523px) 100vw, 523px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-54.png\" alt=\"\" class=\"wp-image-699\" width=\"521\" height=\"607\"\/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-55.png\" alt=\"\" class=\"wp-image-700\" width=\"519\" height=\"272\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-55.png 400w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/02\/\u56fe\u7247-55-300x158.png 300w\" sizes=\"(max-width: 519px) 100vw, 519px\" \/><\/figure>\n\n\n\n<h3>4.9.2 \u53ef\u4ee5\u8c03\u7528\u5176\u4ed6\u7684\u6784\u9020\u65b9\u6cd5<\/h3>\n\n\n\n<ul><li><strong>\u6ce8\u610f\uff1a\u8c03\u7528\u6784\u9020\u65b9\u6cd5\u65f6\u5fc5\u987b\u5728\u9996\u884c<\/strong><\/li><\/ul>\n\n\n\n<h4>4.9.2.1 \u8fd9\u6837\u8c03\u7528\u6784\u9020\u65b9\u6cd5\u662f\u9519\u8bef\u7684\uff0c\u56e0\u4e3a\uff0c\u521b\u5efa\u4e86\u5783\u573e\u5bf9\u8c61<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>class Student {\n    public Student() {\n        System.out.println(\"\u65e0\u53c2\u6570\");\n        \/\/\u8fd9\u6837\u8c03\u7528\u6784\u9020\u65b9\u6cd5\u662f\u9519\u8bef\u7684\uff0c\u56e0\u4e3a\uff0c\u521b\u5efa\u4e86\u5783\u573e\u5bf9\u8c61\n        new Student(1);\n    }\n\n    public Student(int i) {\n        System.out.println(\"1\u53c2\u6570\");\n    }\n\n    public Student(int i, int n) {\n        System.out.println(\"2\u53c2\u6570\");\n    }\n}<\/code><\/pre>\n\n\n\n<h4>4.9.2.2 \u8fd9\u6837\u8c03\u7528\u662f\u6b63\u786e\u7684<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo{\n    public static void main(String&#91;] args){\n        Student student = new Student();\n    }\n}\nclass Student {\n    public Student() {\n        this(10);\n        System.out.println(\"\u65e0\u53c2\u6570\");\n    }\n\n    public Student(int i) {\n        this(1,2);\n        System.out.println(\"1\u53c2\u6570\");\n    }\n\n    public Student(int i, int n) {\n        System.out.println(\"2\u53c2\u6570\");\n    }\n}<\/code><\/pre>\n\n\n\n<h3>4.9.3 this\u53ef\u4ee5\u8c03\u7528\u6210\u5458\u65b9\u6cd5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>public class TestDemo {\n    public static void main(String&#91;] args) {\n        Student student = new Student();\n        student.show();\n    }\n}\nclass Student {\n   public void show(){\n       System.out.println(\"show-method\");\n       this.save();\n   }\n    public void save(){\n        System.out.println(\"show-method\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u8c03\u7528\u6210\u5458\u65b9\u6cd5\u65f6\u4e5f\u53ef\u4ee5\u4e0d\u4f7f\u7528this\u5173\u952e\u5b57(\u63a8\u8350)<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>class Student {\n   public void show(){\n       System.out.println(\"show-method\");\n       save();\n   }\n    public void save(){\n        System.out.println(\"show-method\");\n    }\n}<\/code><\/pre>\n\n\n\n<h3>4.9.4 javaBean<\/h3>\n\n\n\n<ul><li>bean\u5c31\u662f\u4e00\u79cd<strong>\u7279\u6b8a<\/strong>\u7684\u7c7b<\/li><li>\u542b\u6709setter\u548cgetter\u65b9\u6cd5<\/li><li>\u53ef\u4ee5\u770b\u505a\u6570\u636e\u7684\u8f7d\u4f53<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>class Student {\n    private int id;\n    private String name;\n    private String sex;\n    private int age;\n\n    public int getId() {\n        return id;\n    }\n\n    public void setId(int id) {\n        this.id = id;\n    }\n\n    public String getName() {\n        return name;\n    }\n\n    public void setName(String name) {\n        this.name = name;\n    }\n\n    public String getSex() {\n        return sex;\n    }\n\n    public void setSex(String sex) {\n        this.sex = sex;\n    }\n\n    public int getAge() {\n        return age;\n    }\n\n    public void setAge(int age) {\n        this.age = age;\n    }\n}<\/code><\/pre>\n\n\n\n<h2>5.0 \u9879\u76ee-\u4f18\u5316<\/h2>\n\n\n\n<h3>5.0.1 \u9700\u6c42\uff1a<\/h3>\n\n\n\n<ul><li>\u5bf9\u5b66\u751f\u4fe1\u606f\u5b8c\u6210CRUD<\/li><li>\u4f7f\u7528\u6570\u7ec4\u5b58\u50a8\u5b66\u751f\u4fe1\u606f(\u5b66\u751f\u5bf9\u8c61)<\/li><\/ul>\n\n\n\n<h3>5.0.2 \u6280\u672f<\/h3>\n\n\n\n<ul><li>javase+\u6570\u7ec4+\u5faa\u73af<\/li><li>\u6280\u672f\u5206\u6790\uff1a<ul><li>\u521b\u5efa\u4e00\u4e2a\u53ef\u4ee5\u5b58\u50a8\u5b66\u751f\u7c7b\u578b\u7684\u6570\u7ec4<\/li><li>\u521b\u5efa\u4fdd\u5b58\u5b66\u751f\u7684\u65b9\u6cd5\uff1asave<\/li><li>\u663e\u793a\u5b66\u751f\u7684\u65b9\u6cd5\uff1afindAll<\/li><li>\u5220\u9664\u5b66\u751f\u7684\u7684\u65b9\u6cd5\uff1adelete<\/li><li>\u66f4\u65b0\u5b66\u751f\u7684\u65b9\u6cd5\uff1a<ul><li>\u67e5\u8be2\u5230\u9700\u8981\u66f4\u65b0\u7684\u5b66\u751f\uff1afindByid<\/li><li>\u66f4\u65b0\u5b66\u751f\u7684\u4fe1\u606f\uff1aupdate\u53ea\u66f4\u65b0\u59d3\u540d<\/li><\/ul><\/li><li>\u6839\u636e\u5b66\u751f\u7684<strong>\u5b66\u53f7<\/strong>\u67e5\u627e\u5728\u6570\u7ec4\u4e2d\u8fd9\u4e2a\u5b66\u751f\u5bf9\u5e94\u7684\u4e0b\u6807\uff1afindByindex<\/li><\/ul><\/li><\/ul>\n\n\n\n<h3>5.0.3 \u7f16\u7801\u5b9e\u73b0<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>import java.util.Scanner;\n\npublic class TestDemo {\n\n    \/\/\u521b\u5efa\u4e00\u4e2a\u5b66\u751f\u6570\u7ec4\n    static Student&#91;] array = new Student&#91;3];\n\n    \/***\n     * TODO \u6309\u7167\u5b66\u53f7\u67e5\u627e\u5bf9\u5e94\u5b66\u751f\u7684\u4e0b\u6807\uff0c\u5982\u679csid=0\u8868\u793a\u9700\u8981\u627e\u7a7a\u4f4d\u7f6e\u5b8c\u6210\u6dfb\u52a0\n     * @param sid   \u8868\u793a\u5b66\u53f7\n     * @return  \u4e0b\u6807\n     *\/\n    public static int findByIndex(int sid){\n        \/\/\u5faa\u73af\n        for (int index = 0; index &lt; array.length; index++) {\n            \/\/\u6839\u636e\u4e0b\u6807\u83b7\u53d6\u5bf9\u5e94\u7684\u5b66\u751f\u5bf9\u8c61\n            Student student = array&#91;index];\n            \/\/\u5224\u65ad\u662f\u5426\u5b58\u5728\n            if (sid==0){\n                if (student==null){\n                    return index;\n                }\n            }else{\n                if (student!=null &amp;&amp; student.getId()==sid){\n                    return index;\n                }\n            }\n\n        }\n        return -1;\n    }\n\n    \/***\n     * TODO \u4fdd\u5b58\u5b66\u751f\u4fe1\u606f\n     * @param student   \u5b66\u751f\u5bf9\u8c61(\u5730\u5740)\n     *\/\n    public static void save(Student student){\n        \/\/\u83b7\u53d6\u4e00\u4e2a\u7a7a\u4f4d\u7f6e\n        if (student!=null){\n            int index = findByIndex(0);\n            if (index!=-1){\n                \n                array&#91;index] = student;\n                System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n            }else{\n                System.out.println(\"\u6ee1\u4e86\");\n            }\n        }else{\n            System.out.println(\"\u8bf7\u6dfb\u52a0\u5b66\u751f\u4fe1\u606f\");\n        }\n    }\n\n    \/**\n     *  TODO \u663e\u793a\u5b66\u751f\u4fe1\u606f\n     *\/\n    public static void findAll(){\n        \/\/\u904d\u5386\u6570\u7ec4\u4e2d\u5b66\u751f\u7684\u4fe1\u606f\n        for (int index = 0; index &lt; array.length; index++) {\n            \/\/\u83b7\u53d6\u5b66\u751f\u5bf9\u8c61\n            Student student = array&#91;index];\n            if (student!=null){\n                System.out.println(\"\u5b66\u53f7\uff1a\"+student.getId()+\"\\t\"+\n                        \"\u59d3\u540d\uff1a\"+student.getName()+\"\\t\"+\n                        \"\u6027\u522b\uff1a\"+student.getSex()+\"\\t\"+\n                        \"\u5e74\u9f84\uff1a\"+student.getAge()\n                );\n            }\n        }\n    }\n\n    \/***\n     * TODO \u5220\u9664\u5b66\u751f\n     * @param sid   \u5b66\u53f7\n     *\/\n    public static void delete(int sid){\n        \/\/\u83b7\u53d6\u5b66\u751f\u5728\u6570\u7ec4\u4e2d\u7684\u4f4d\u7f6e\n        int index = findByIndex(sid);\n        \/\/\u5224\u65ad\n        if (index!=-1){\n            array&#91;index] = null;\n            System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n        }else{\n            System.out.println(\"\u67e5\u65e0\u6b64\u5b66\u751f\uff0c\u8bf7\u91cd\u65b0\u8f93\u5165\u5b66\u53f7\");\n        }\n\n    }\n\n    public static void update(int sid,String name){\n        \/\/\u6309\u7167\u5b66\u53f7\u67e5\u627e\u5bf9\u5e94\u7684\u4e0b\u6807\n        int index = findByIndex(sid);\n        \/\/\u5224\u65ad\n        if (index!=-1) {\n            \/\/\u83b7\u53d6\u8fd9\u4e2a\u5b66\u751f\n            Student student = array&#91;index];\n            \/\/\u4fee\u6539\u59d3\u540d\n            student.setName(name);\n            System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n        }else{\n            System.out.println(\"\u67e5\u65e0\u6b64\u5b66\u751f\uff0c\u8bf7\u91cd\u65b0\u8f93\u5165\u5b66\u53f7\");\n        }\n\n    }\n\n    \/***\n     * TODO \u6d4b\u8bd5\u65b9\u6cd5\n     * @param args\n     *\/\n    public static void main(String&#91;] args) {\n        \/\/\u63a7\u5236\u53f0\u5bf9\u8c61\n        Scanner scanner = new Scanner(System.in);\n        \/\/\u8df3\u51fa\u5faa\u73af\u4f53\n        boolean flag = true;\n        \/\/\u63d0\u793a\n        System.out.println(\"1\u6dfb\u52a0;2\u663e\u793a;3\u5220\u9664;4\u66f4\u65b0;5\u9000\u51fa\");\n        \/\/\u5faa\u73af\n        do {\n            \/\/key\n            int key = scanner.nextInt();\n            switch (key){\n                case 1:\/\/\u8c03\u7528\u65b9\u6cd5\n                    Student student = new Student();\n                    \/\/\u63d0\u793a\u4fe1\u606f\n                    System.out.println(\"\u8bf7\u8f93\u5165\u5b66\u53f7\");\n                    student.setId(scanner.nextInt());\n                    System.out.println(\"\u8bf7\u8f93\u5165\u59d3\u540d\");\n                    student.setName(scanner.next());\n                    System.out.println(\"\u8bf7\u8f93\u5165\u6027\u522b\");\n                    student.setSex(scanner.next());\n                    System.out.println(\"\u8bf7\u8f93\u5165\u5e74\u9f84\");\n                    student.setAge(scanner.nextInt());\n                    \/\/\u4fdd\u5b58\n                    save(student);\n                    break;\n                case 2:\/\/\u8c03\u7528\u65b9\u6cd5\n                    findAll();\n                    break;\n                case 3:\n                    System.out.println(\"\u8bf7\u8f93\u5165\u5b66\u53f7\");\n                    delete(scanner.nextInt());\n                    break;\n                case 4:\n                    System.out.println(\"\u8bf7\u8f93\u5165\u5b66\u53f7\");\n                    int sid = scanner.nextInt();\n                    System.out.println(\"\u8bf7\u8f93\u5165\u59d3\u540d\");\n                    String name = scanner.next();\n                    \/\/\u66f4\u65b0\n                    update(sid,name);\n                    break;\n                case 5:\n                    flag = false;\n                    break;\n            }\n        }while(flag);\n\n    }\n}\nclass Student {\n    private int id;         \/\/\u5b66\u53f7\n    private String name;    \/\/\u5b66\u751f\u59d3\u540d\n    private String sex;     \/\/\u5b66\u751f\u6027\u522b\n    private int age;        \/\/\u5b66\u751f\u5e74\u9f84\n\n    public int getId() {\n        return id;\n    }\n\n    public void setId(int id) {\n        this.id = id;\n    }\n\n    public String getName() {\n        return name;\n    }\n\n    public void setName(String name) {\n        this.name = name;\n    }\n\n    public String getSex() {\n        return sex;\n    }\n\n    public void setSex(String sex) {\n        this.sex = sex;\n    }\n\n    public int getAge() {\n        return age;\n    }\n\n    public void setAge(int age) {\n        this.age = age;\n    }\n}<\/code><\/pre>\n\n\n\n<h3>5.0.4 \u7f16\u7801\u5b9e\u73b0-\u4f18\u5316\u7248<\/h3>\n\n\n\n<h4>5.0.4.1 \u6269\u5c55<\/h4>\n\n\n\n<ul><li>\u8fd4\u56de\u5b57\u7b26\u4e32<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>import java.util.UUID;\n\npublic class Demo1 {\n    public static void main(String&#91;] args){\n        \/\/\u4e0d\u91cd\u590d\n        String str = UUID.randomUUID().toString();\n        System.out.println(str);\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u8fd4\u56delong<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>import java.util.UUID;\nimport java.util.zip.CRC32;\n\npublic class Demo1 {\n    public static void main(String&#91;] args){\n        \/\/\u4e0d\u91cd\u590d\n        String str = UUID.randomUUID().toString();\n        CRC32 crc32 = new CRC32();\n        crc32.update(str.getBytes());\n        \/\/\u83b7\u53d6\n        long value = crc32.getValue();\n        System.out.println(value);\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u5b9e\u73b0<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>import java.util.Scanner;\nimport java.util.UUID;\nimport java.util.zip.CRC32;\n\npublic class TestDemo {\n\n    \/\/\u521b\u5efa\u4e00\u4e2a\u5b66\u751f\u6570\u7ec4\n    static Student&#91;] array = new Student&#91;3];\n\n    \/***\n     * TODO \u6309\u7167\u5b66\u53f7\u67e5\u627e\u5bf9\u5e94\u5b66\u751f\u7684\u4e0b\u6807\uff0c\u5982\u679csid=0\u8868\u793a\u9700\u8981\u627e\u7a7a\u4f4d\u7f6e\u5b8c\u6210\u6dfb\u52a0\n     * @param sid   \u8868\u793a\u5b66\u53f7\n     * @return  \u4e0b\u6807\n     *\/\n    public static int findByIndex(int sid){\n        \/\/\u5faa\u73af\n        for (int index = 0; index &lt; array.length; index++) {\n            \/\/\u6839\u636e\u4e0b\u6807\u83b7\u53d6\u5bf9\u5e94\u7684\u5b66\u751f\u5bf9\u8c61\n            Student student = array&#91;index];\n            \/\/\u5224\u65ad\u662f\u5426\u5b58\u5728\n            if (sid==0){\n                if (student==null){\n                    return index;\n                }\n            }else{\n                if (student!=null &amp;&amp; student.getId()==sid){\n                    return index;\n                }\n            }\n\n        }\n        return -1;\n    }\n\n    \/***\n     * TODO \u4fdd\u5b58\u5b66\u751f\u4fe1\u606f\n     * @param student   \u5b66\u751f\u5bf9\u8c61(\u5730\u5740)\n     *\/\n    public static void save(Student student){\n        \/\/\u83b7\u53d6\u4e00\u4e2a\u7a7a\u4f4d\u7f6e\n        if (student!=null){\n            int index = findByIndex(0);\n            if (index!=-1){\n                array&#91;index] = student;\n                System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n            }else{\n                System.out.println(\"\u6ee1\u4e86\");\n            }\n        }else{\n            System.out.println(\"\u8bf7\u6dfb\u52a0\u5b66\u751f\u4fe1\u606f\");\n        }\n    }\n\n    \/**\n     *  TODO \u663e\u793a\u5b66\u751f\u4fe1\u606f\n     *\/\n    public static void findAll(){\n        \/\/\u904d\u5386\u6570\u7ec4\u4e2d\u5b66\u751f\u7684\u4fe1\u606f\n        for (int index = 0; index &lt; array.length; index++) {\n            \/\/\u83b7\u53d6\u5b66\u751f\u5bf9\u8c61\n            Student student = array&#91;index];\n            if (student!=null){\n                System.out.println(\"\u5b66\u53f7\uff1a\"+student.getId()+\"\\t\"+\n                        \"\u59d3\u540d\uff1a\"+student.getName()+\"\\t\"+\n                        \"\u6027\u522b\uff1a\"+student.getSex()+\"\\t\"+\n                        \"\u5e74\u9f84\uff1a\"+student.getAge()\n                );\n            }\n        }\n    }\n\n    \/***\n     * TODO \u5220\u9664\u5b66\u751f\n     * @param sid   \u5b66\u53f7\n     *\/\n    public static void delete(int sid){\n        \/\/\u83b7\u53d6\u5b66\u751f\u5728\u6570\u7ec4\u4e2d\u7684\u4f4d\u7f6e\n        int index = findByIndex(sid);\n        \/\/\u5224\u65ad\n        if (index!=-1){\n            array&#91;index] = null;\n            System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n        }else{\n            System.out.println(\"\u67e5\u65e0\u6b64\u5b66\u751f\uff0c\u8bf7\u91cd\u65b0\u8f93\u5165\u5b66\u53f7\");\n        }\n\n    }\n\n    public static void update(int sid,String name){\n        \/\/\u6309\u7167\u5b66\u53f7\u67e5\u627e\u5bf9\u5e94\u7684\u4e0b\u6807\n        int index = findByIndex(sid);\n        \/\/\u5224\u65ad\n        if (index!=-1) {\n            \/\/\u83b7\u53d6\u8fd9\u4e2a\u5b66\u751f\n            Student student = array&#91;index];\n            \/\/\u4fee\u6539\u59d3\u540d\n            student.setName(name);\n            System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n        }else{\n            System.out.println(\"\u67e5\u65e0\u6b64\u5b66\u751f\uff0c\u8bf7\u91cd\u65b0\u8f93\u5165\u5b66\u53f7\");\n        }\n\n    }\n\n    public static long getValue(){\n        \/\/\u4e0d\u91cd\u590d\n        String str = UUID.randomUUID().toString();\n        CRC32 crc32 = new CRC32();\n        crc32.update(str.getBytes());\n        \/\/\u83b7\u53d6\n        long value = crc32.getValue();\n        return value;\n    }\n\n    \/***\n     * TODO \u6d4b\u8bd5\u65b9\u6cd5\n     * @param args\n     *\/\n    public static void main(String&#91;] args) {\n        \/\/\u63a7\u5236\u53f0\u5bf9\u8c61\n        Scanner scanner = new Scanner(System.in);\n        \/\/\u8df3\u51fa\u5faa\u73af\u4f53\n        boolean flag = true;\n        \/\/\u63d0\u793a\n        System.out.println(\"1\u6dfb\u52a0;2\u663e\u793a;3\u5220\u9664;4\u66f4\u65b0;5\u9000\u51fa\");\n        \/\/\u5faa\u73af\n        do {\n            \/\/key\n            int key = scanner.nextInt();\n            switch (key){\n                case 1:\/\/\u8c03\u7528\u65b9\u6cd5\n                    Student student = new Student();\n                    \/\/\u63d0\u793a\u4fe1\u606f\n                    student.setId((int)getValue());\n                    System.out.println(\"\u8bf7\u8f93\u5165\u59d3\u540d\");\n                    student.setName(scanner.next());\n                    System.out.println(\"\u8bf7\u8f93\u5165\u6027\u522b\");\n                    student.setSex(scanner.next());\n                    System.out.println(\"\u8bf7\u8f93\u5165\u5e74\u9f84\");\n                    student.setAge(scanner.nextInt());\n                    \/\/\u4fdd\u5b58\n                    save(student);\n                    break;\n                case 2:\/\/\u8c03\u7528\u65b9\u6cd5\n                    findAll();\n                    break;\n                case 3:\n                    System.out.println(\"\u8bf7\u8f93\u5165\u5b66\u53f7\");\n                    delete(scanner.nextInt());\n                    break;\n                case 4:\n                    System.out.println(\"\u8bf7\u8f93\u5165\u5b66\u53f7\");\n                    int sid = scanner.nextInt();\n                    System.out.println(\"\u8bf7\u8f93\u5165\u59d3\u540d\");\n                    String name = scanner.next();\n                    \/\/\u66f4\u65b0\n                    update(sid,name);\n                    break;\n                case 5:\n                    flag = false;\n                    break;\n            }\n        }while(flag);\n\n    }\n}\nclass Student {\n    private int id;         \/\/\u5b66\u53f7\n    private String name;    \/\/\u5b66\u751f\u59d3\u540d\n    private String sex;     \/\/\u5b66\u751f\u6027\u522b\n    private int age;        \/\/\u5b66\u751f\u5e74\u9f84\n\n    public int getId() {\n        return id;\n    }\n\n    public void setId(int id) {\n        this.id = id;\n    }\n\n    public String getName() {\n        return name;\n    }\n\n    public void setName(String name) {\n        this.name = name;\n    }\n\n    public String getSex() {\n        return sex;\n    }\n\n    public void setSex(String sex) {\n        this.sex = sex;\n    }\n\n    public int getAge() {\n        return age;\n    }\n\n    public void setAge(int age) {\n        this.age = age;\n    }\n}<\/code><\/pre>\n\n\n\n<h2>5.1 \u9759\u6001\u5173\u952e\u5b57static<\/h2>\n\n\n\n<h3>5.1.1 \u4fee\u9970<\/h3>\n\n\n\n<ul><li>\u53ef\u4ee5\u4fee\u9970\u53d8\u91cf\u3001\u65b9\u6cd5\u3001\u4ee3\u7801\u5757<\/li><li>\u7279\u70b9\uff1a<ul><li>\u4f7f\u7528static\u4fee\u9970\u7684<strong>\u7c7b<\/strong>\u53ef\u4ee5\u76f4\u63a5\u52a0\u8f7d\u6267\u884c\uff0c\u6240\u4ee5\uff0cstatic\u4fee\u9970\u7684\u53d8\u91cf\u4e5f\u6210\u4e3a<strong>\u7c7b\u53d8\u91cf<\/strong><\/li><li>static\u4fee\u9970\u7684\u4ee3\u7801\u5757\u79f0\u4e3a\u9759\u6001\u4ee3\u7801\u5757\uff0cJVM\u52a0\u8f7d\u7c7b\u7684\u65f6\u5019\uff0c\u4f1a\u6267\u884c\u9759\u6001\u4ee3\u7801\u5757\u4e2d\u7684\u5185\u5bb9<\/li><\/ul><\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"1024\" height=\"170\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-1024x170.png\" alt=\"\" class=\"wp-image-726\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-1024x170.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-300x50.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-768x128.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247.png 1256w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h3>5.1.2 \u91c7\u7528\u9759\u6001\u53d8\u91cf\u5b9e\u73b0\u7d2f\u52a0\u5668<\/h3>\n\n\n\n<ul><li>\u6ca1\u6709\u91c7\u7528\u9759\u6001\u53d8\u91cf\uff0c\u800c\u662f\u6210\u5458\u53d8\u91cf\uff0c\u6240\u4ee5\u4e0d\u4f1a\u5b9e\u73b0\u7d2f\u52a0\u5668\u7684\u6548\u679c<\/li><li>\u56e0\u4e3a\uff0c\u6210\u5458\u53d8\u91cf\u5c5e\u4e8e\u5f53\u524d\u5bf9\u8c61\uff0c\u4e0d\u4f1a\u88ab\u5171\u4eab<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo1 {\n    public static void main(String&#91;] args){\n        \/\/\u521b\u5efa\u5bf9\u8c61\n        Student student1 = new Student();\n        Student student2 = new Student();\n        \/\/\u83b7\u53d6\u6210\u5458\u53d8\u91cf\n        System.out.println(student1.getCount());\n        System.out.println(student2.getCount());\n    }\n}\n\nclass Student{\n    \/\/\u6210\u5458\u53d8\u91cf(\u5c5e\u6027)\n    private int count;\n\n    \/\/\u6784\u9020\u65b9\u6cd5\n    public Student(){\n        count++;\n    }\n\n    \/\/\u83b7\u53d6\u5c5e\u6027\n    public int getCount(){\n        return count;\n    }\n}<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-1.png\" alt=\"\" class=\"wp-image-727\" width=\"839\" height=\"393\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-1.png 828w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-1-300x141.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-1-768x360.png 768w\" sizes=\"(max-width: 839px) 100vw, 839px\" \/><\/figure>\n\n\n\n<ul><li>\u91c7\u7528\u9759\u6001\u53d8\u91cf\u5b8c\u6210\u7d2f\u52a0\u5668\u7684\u529f\u80fd<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo1 {\n    public static void main(String&#91;] args){\n        \/\/\u521b\u5efa\u5bf9\u8c61\n        Student student1 = new Student();\n        Student student2 = new Student();\n        \/\/\u83b7\u53d6\u9759\u6001\u53d8\u91cf\n        System.out.println(student1.getCount());\n        System.out.println(student2.getCount());\n    }\n}\n\nclass Student{\n    \/\/\u9759\u6001\u53d8\u91cf\n    private static int count;\n\n    \/\/\u6784\u9020\u65b9\u6cd5\n    public Student(){\n        count++;\n    }\n\n    \/\/\u83b7\u53d6\u5c5e\u6027\n    public int getCount(){\n        return count;\n    }\n}<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-2.png\" alt=\"\" class=\"wp-image-729\" width=\"838\" height=\"663\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-2.png 830w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-2-300x237.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-2-768x608.png 768w\" sizes=\"(max-width: 838px) 100vw, 838px\" \/><\/figure>\n\n\n\n<ul><li>static\u58f0\u660e\u7684\u53d8\u91cf\u901a\u8fc7\u8be5\u7c7bnew\u51fa\u7684\u5bf9\u8c61\uff0c\u90fd\u53ef\u4ee5\"\u5171\u4eab\"\uff0c\u90fd\u53ef\u4ee5\u901a\u8fc7\u5bf9\u8c61\u8bbf\u95ee<\/li><li>\u7c7b\u4e5f\u53ef\u4ee5\u76f4\u63a5\u8bbf\u95ee\uff0c\u6240\u4ee5\uff0c\u6211\u4eec\u79f0\u4e3a\"\u7c7b\u53d8\u91cf\"<\/li><li>\u7c7b\u76f4\u63a5\u8c03\u7528<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo1 {\n    public static void main(String&#91;] args){\n        System.out.println(Student.count);\n    }\n}\n\nclass Student{\n    \/\/\u9759\u6001\u53d8\u91cf\n    public static int count;\n}<\/code><\/pre>\n\n\n\n<h3>5.1.3 \u7b14\u8bd5\u9898<\/h3>\n\n\n\n<h4>5.1.3.1 \u9759\u6001\u65b9\u6cd5\u4e2d\u662f\u5426\u53ef\u4ee5\u8bbf\u95ee\u5b9e\u4f8b\u53d8\u91cf\u3001\u5b9e\u4f8b\u65b9\u6cd5\u6216this\u5173\u952e\u5b57\uff1f<\/h4>\n\n\n\n<p>\u7b54\uff1a\u4e0d\u80fd\uff0c\u56e0\u4e3a\uff0c\u9759\u6001\u4fee\u9970\u7684\u5728\u7c7b\u52a0\u8f7d\u5668\u5c31\u521d\u59cb\u4e86\uff0c\u800c\u5bf9\u8c61\u8fd9\u4e2a\u65f6\u5019\u8fd8\u4e0d\u5b58\u5728<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-3.png\" alt=\"\" class=\"wp-image-730\" width=\"839\" height=\"351\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-3.png 812w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-3-300x126.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-3-768x322.png 768w\" sizes=\"(max-width: 839px) 100vw, 839px\" \/><\/figure>\n\n\n\n<ul><li>\u6211\u4eec\u53ef\u4ee5\u6539\u5584\u4e00\u4e0b\u4ee3\u7801<ul><li>\u628a\u65b9\u6cd5\u4fee\u6539\u4e3astatic\u4fee\u9970<\/li><\/ul><\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-4.png\" alt=\"\" class=\"wp-image-731\" width=\"839\" height=\"403\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-4.png 721w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-4-300x144.png 300w\" sizes=\"(max-width: 839px) 100vw, 839px\" \/><\/figure>\n\n\n\n<ul><li>\u4f7f\u7528\u5bf9\u8c61\u8c03\u7528<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" width=\"853\" height=\"336\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-5.png\" alt=\"\" class=\"wp-image-732\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-5.png 853w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-5-300x118.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-5-768x303.png 768w\" sizes=\"(max-width: 853px) 100vw, 853px\" \/><\/figure>\n\n\n\n<ul><li>\u4e0d\u80fd\u5728\u9759\u6001\u4e2d\u76f4\u63a5\u4f7f\u7528this<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-6.png\" alt=\"\" class=\"wp-image-733\" width=\"838\" height=\"334\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-6.png 737w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-6-300x120.png 300w\" sizes=\"(max-width: 838px) 100vw, 838px\" \/><\/figure>\n\n\n\n<h4>5.1.3.2 \u9759\u6001\u65b9\u6cd5\u7684\u521d\u59cb\u5316\u987a\u5e8f<\/h4>\n\n\n\n<ul><li>\u5c31\u662f\u6309\u7167static\u4fee\u6539\u7684\u987a\u5e8f\u6267\u884c<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo1 {\n\n    static{\n        System.out.println(1);\n    }\n\n    static{\n        System.out.println(2);\n    }\n\n    static{\n        System.out.println(3);\n    }\n\n    public static void main(String&#91;] args){\n        System.out.println(4);\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u8f93\u51fa\u4e3a1234\uff0c\u56e0\u4e3a\uff0c\u4e3b\u65b9\u6cd5\u9700\u8981\u538b\u6808\u540e\u624d\u6267\u884c\uff0c\u9759\u6001\u5757\u53ef\u4ee5\u76f4\u63a5\u6267\u884c<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo1 {\n    public static void main(String&#91;] args){\n        System.out.println(4);\n    }\n\n    static{\n        System.out.println(1);\n    }\n\n    static{\n        System.out.println(2);\n    }\n\n    static{\n        System.out.println(3);\n    }\n}<\/code><\/pre>\n\n\n\n<h4>5.1.3.3 \u6267\u884c\u7684\u987a\u5e8f<\/h4>\n\n\n\n<ul><li>1\u9759\u6001\u5757 2\u8bed\u53e5\u5757 3\u6784\u9020\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo1 {\n    public static void main(String&#91;] args){\n        \/\/\u521b\u5efa\u5bf9\u8c61\u65f6\uff0c1\u9759\u6001\u5757 2\u8bed\u53e5\u5757 3\u6784\u9020\u65b9\u6cd5\n        Student student = new Student();\n    }\n}\n\nclass Student{\n    \/\/\u9759\u6001\u53d8\u91cf\n    public Student(){\n        System.out.println(\"\u6784\u9020\u65b9\u6cd5\");\n    }\n    \/\/\u9759\u6001\u5757\n    static{\n        System.out.println(\"\u9759\u6001\u5757\");\n    }\n    \/\/\u8bed\u53e5\u5757\n    {\n        System.out.println(\"\u8bed\u53e5\u5757\");\n    }\n}<\/code><\/pre>\n\n\n\n<h2>5.2 \u8bbe\u8ba1\u6a21\u5f0f<\/h2>\n\n\n\n<ul><li>\u8bbe\u8ba1\u6a21\u5f0f\uff1a\u5c31\u662f\u4e00\u79cd\u53ef\u4ee5\u53cd\u590d\u5229\u7528\u7684\u89e3\u51b3\u65b9\u6848\uff1b<\/li><li>\u8bbe\u8ba1\u6a21\u5f0f\u662f1995\u5e74\u7531GOF4\u4eba\u7ec4\u63d0\u51fa<\/li><li>\u8bbe\u8ba1\u6a21\u5f0f\uff1a23\u79cd<\/li><li>\u4ece\u7ed3\u6784\u4e0a\u5206\u4e3a\uff1a<ul><li>\u521b\u5efa\u578b<\/li><li>\u7ed3\u6784\u578b<\/li><li>\u884c\u4e3a\u578b<\/li><\/ul><\/li><\/ul>\n\n\n\n<h3>5.2.1 \u5355\u4f8b\u6a21\u5f0f<\/h3>\n\n\n\n<ul><li>\u5355\u4f8b\u6a21\u5f0f\uff1a\u5c31\u662f\u5355\u5b9e\u4f8b(\u4e00\u4e2a\u5bf9\u8c61)\u7684\u4e00\u79cd\u6a21\u5f0f\uff0c\u4e5f\u79f0\u4e3a\"\u53cd\u6a21\u5f0f\"<\/li><li>\u4f18\u7f3a\u70b9\uff1a<ul><li>\u4f18\u70b9\uff1a\u5806\u4e2d\u53ea\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61\uff0c\u4f7f\u7528\u5806\u5185\u5b58\u5c11\uff0c\u6210\u672c\u4f4e<\/li><li>\u7f3a\u70b9\uff1a\u56e0\u4e3a\u5bf9\u8c61\u662f\u88ab\u5171\u4eab\u7684\uff0c\u6240\u4ee5\uff0c\u6709\u5b89\u5168\u95ee\u9898\u3002<\/li><\/ul><\/li><li>\u521b\u5efa\u5355\u4f8b\u6a21\u5f0f\uff1a<ul><li>\u6784\u9020\u65b9\u6cd5\u79c1\u6709\u5316<\/li><li>\u521b\u5efa\u4e00\u4e2a\u79c1\u6709\u7684\u3001\u9759\u6001\u7684\u3001\u672c\u7c7b\u578b\u5bf9\u8c61<\/li><li>\u521b\u5efa\u4e00\u4e2a\u516c\u6709\u7684\u3001\u9759\u6001\u7684\u3001\u8fd4\u56de\u672c\u7c7b\u578b\u7684\u65b9\u6cd5<\/li><li><strong>\u81ea\u5f8b\u6a21\u5f0f<\/strong><\/li><\/ul><\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo1 {\n    public static void main(String&#91;] args){\n        Student student1 = Student.getInstance();\n        Student student2 = Student.getInstance();\n        \/\/\u6bd4\u8f83\u4e24\u4e2a\u5bf9\u8c61\u7684\u5185\u5b58\u5730\u5740\n        System.out.println(student2 == student1);\n    }\n}\n\/\/\u5355\u4f8b\u6a21\u5f0f\uff1a\u997f\u6c49\u5f0f\uff1a\u63a8\u8350\u4f7f\u7528\nclass Student{\n    \/\/\u521b\u5efa\u4e00\u4e2a\u79c1\u6709\u7684\u3001\u9759\u6001\u7684\u5bf9\u8c61\n    private static Student student = new Student();\n    \/\/\u79c1\u6709\u5316\n    private Student(){}\n\n    \/\/\u521b\u5efa\u4e00\u4e2a\u516c\u6709\u7684\u3001\u9759\u6001\u7684\u3001\u8fd4\u56de\u672c\u7c7b\u578b\n    public static Student getInstance(){\n        return student;\n    }\n\n    \/\/\u6210\u5458\u65b9\u6cd5\n    public void method(){\n        System.out.println(\"\u6210\u5458\u65b9\u6cd5\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u5355\u4f8b\u6a21\u5f0f<ul><li>\u997f\u6c49\u5f0f\uff1a\u63a8\u8350\u4f7f\u7528<\/li><li>\u61d2\u6c49\u5f0f\uff1a\u52a0\u9501--\u53d8\u4e3a\u81ea\u65cb\u9501<\/li><\/ul><\/li><li>\u53ef\u4ee5\u8c03\u7528\u6210\u5458\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo1 {\n    public static void main(String&#91;] args){\n        Student student1 = Student.getInstance();\n        \/\/\u53ef\u4ee5\u901a\u8fc7\u5355\u4f8b\u5bf9\u8c61\u8c03\u7528\u6210\u5458\u65b9\u6cd5\u4e86\n        student1.method();\n    }\n}\n\/\/\u5355\u4f8b\u6a21\u5f0f\uff1a\u997f\u6c49\u5f0f\nclass Student{\n    \/\/\u521b\u5efa\u4e00\u4e2a\u79c1\u6709\u7684\u3001\u9759\u6001\u7684\u5bf9\u8c61\n    private static Student student = new Student();\n    \n    \/\/\u79c1\u6709\u5316\n    private Student(){}\n\n    \/\/\u521b\u5efa\u4e00\u4e2a\u516c\u6709\u7684\u3001\u9759\u6001\u7684\u3001\u8fd4\u56de\u672c\u7c7b\u578b\n    public static Student getInstance(){\n        return student;\n    }\n\n    \/\/\u6210\u5458\u65b9\u6cd5\n    public void method(){\n        System.out.println(\"\u6210\u5458\u65b9\u6cd5\");\n    }\n}<\/code><\/pre>\n\n\n\n<h2>5.3 \u4f18\u5316\u9879\u76ee<\/h2>\n\n\n\n<h3>5.3.1 \u5206\u7c7b\u5b8c\u6210\u529f\u80fd<\/h3>\n\n\n\n<ul><li>\u4f7f\u7528\u6570\u7ec4\u6a21\u62df\u6570\u636e\u5e93\uff1a\u53ef\u4ee5\u521b\u5efa\u4e00\u4e2a\u5355\u72ec\u7684\u7c7b<\/li><li>\u5b9e\u73b0\u529f\u80fdCRUD\uff1a\u72ec\u7acb\u7684\u7c7b\u5b8c\u6210<\/li><li>\u524d\u7aef\uff1a\u72ec\u7acb\u7c7b\u5b8c\u6210<\/li><\/ul>\n\n\n\n<h3>5.3.2 \u5f00\u53d1<\/h3>\n\n\n\n<p><strong>\u5f00\u53d1\u6d41\u7a0b\u56fe\uff1a\u5f00\u53d1\u5c31\u662f\u8fd9\u4e2a\u8fc7\u7a0b\u7684\u5012\u8fc7\u7a0b<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"1024\" height=\"161\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-7-1024x161.png\" alt=\"\" class=\"wp-image-734\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-7-1024x161.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-7-300x47.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-7-768x121.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-7.png 1106w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h4>5.3.2.1 \u521b\u5efa\u5b9e\u4f53\u7c7b\uff1a\u5373javaBean<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Student {\n    private int id;\n    private String username;\n    private String sex;\n    private int age;\n\n    public int getId() {\n        return id;\n    }\n\n    public void setId(int id) {\n        this.id = id;\n    }\n\n    public String getUsername() {\n        return username;\n    }\n\n    public void setUsername(String username) {\n        this.username = username;\n    }\n\n    public String getSex() {\n        return sex;\n    }\n\n    public void setSex(String sex) {\n        this.sex = sex;\n    }\n\n    public int getAge() {\n        return age;\n    }\n\n    public void setAge(int age) {\n        this.age = age;\n    }\n}<\/code><\/pre>\n\n\n\n<h4>5.3.2.2 \u521b\u5efa\u6570\u636e\u5e93\u7c7b\uff1a\u5c31\u662f\u7ba1\u7406\u6570\u7ec4\u7684<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class DataBaseYgm {\n    \/\/\u6784\u9020\u65b9\u6cd5\u79c1\u6709\u5316\n    private DataBaseYgm(){}\n\n    \/\/\u521b\u5efa\u5bf9\u8c61\n    private static DataBaseYgm dataBaseYgm = new DataBaseYgm();\n\n    \/\/\u521b\u5efa\u65b9\u6cd5\n    public static DataBaseYgm getInstance(){\n        return dataBaseYgm;\n    }\n\n    \/\/\u521b\u5efa\u6570\u636e\u5e93\n    private Student&#91;] students = new Student&#91;3];\n    \/\/\u8fd4\u56de\u6570\u7ec4\u7684\u65b9\u6cd5\uff1a\u6210\u5458\u65b9\u6cd5\n    public Student&#91;] getStudents(){\n        return students;\n    }\n}<\/code><\/pre>\n\n\n\n<h4>5.3.2.3 \u4e1a\u52a1\u7c7bservice<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>import java.util.Scanner;\n\n\/\/\u4e1a\u52a1\u7c7b\npublic class StudentService {\n    \/\/\u521b\u5efa\u63a7\u5236\u53f0\n    Scanner scanner = new Scanner(System.in);\n    \/\/\u4f9d\u8d56\u6570\u636e\u5e93\n    private Student&#91;] array = DataBaseYgm.getInstance().getStudents();\n\n    \/**\n     * \u83b7\u53d6\u5bf9\u5e94\u4e0b\u6807\n     * @param sid \u5b66\u53f7\n     * @return \u5bf9\u5e94\u7684\u4e0b\u6807\n     *\/\n    public int findByIndex(int sid){\n        \/\/\u83b7\u53d6\u5b66\u751f\u5bf9\u8c61\n        for (int index = 0; index&lt;array.length; index++){\n            Student student = array&#91;index];\n            \/\/\u5224\u65ad\n            if (sid == 0){\n                if (student == null) return index;\n            }else{\n                if (student!=null &amp;&amp; student.getId() == sid ){\n                    return index;\n                }\n            }\n        }\n        return -1;\n    }\n    \/\/\u4fdd\u5b58\u5b66\u751f\n    public void save(Student student){\n        if (student!=null){\n            \/\/\u83b7\u53d6\u4e00\u4e2a\u7a7a\u4f4d\u7f6e\n            int index = findByIndex(0);\n            if (index!=-1){\n                array&#91;index] = student;\n            }else{\n                System.out.println(\"\u6ee1\u4e86\");\n            }\n        }else{\n            System.out.println(\"\u8bf7\u8f93\u5165\u5b66\u751f\u4fe1\u606f\");\n        }\n    }\n\n    \/**\n     * TODO \u67e5\u8be2\u6240\u6709\u5b66\u751f\n     *\/\n    \/\/\u67e5\u8be2\u5b66\u751f\n    public Student findUid(int id) {\n        int index = findByIndex(id);\n        \/\/\u5224\u65ad\n        if (index != -1) {\n            return array&#91;index];\n        } else {\n            return null;\n        }\n    }\n    \/**\n     * TODO \u5220\u9664\u5b66\u751f\n     * @param sid \u5b66\u53f7\n     *\/\n    \/\/\u5220\u9664\u5b66\u751f\n    public void delete(int sid){\n        \/\/\u83b7\u53d6\u5b66\u751f\u5728\u6570\u7ec4\u4e2d\u7684\u4f4d\u7f6e\n        int index = findByIndex(sid);\n        \/\/\u5224\u65ad\n        if (index != -1){\n            array&#91;index] = null;\n            System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n        }else{\n            System.out.println(\"\u65e0\u6b64\u5b66\u751f\u4fe1\u606f\uff0c\u8bf7\u91cd\u65b0\u8f93\u5165\");\n        }\n    }\n    \/\/\u66f4\u65b0\u5b66\u751f\n    public void update(Student student) {\n        if (student != null) {\n            int index = findByIndex(student.getId());\n            \/\/\u5224\u65ad\n            if (index != -1) {\n                array&#91;index] = student;\n            }else{\n                System.out.println(\"\u67e5\u65e0\u6b64\u5b66\u751f\");\n            }\n        } else {\n            System.out.println(\"\u8bf7\u8f93\u5165\u5b66\u751f\u4fe1\u606f\");\n        }\n    }\n    \/\/\u663e\u793a\n    public void findAll(){\n        \/\/\u52a0\u5f3afor\u5faa\u73af\n        for (Student student : array) {\n            if (student!=null) {\n                System.out.println(\"id=\"+student.getId()+\"\\t username=\"+\n                        student.getUsername()+\"\\t sex=\"+\n                        student.getSex()+\"\\t age=\"+\n                        student.getAge());\n            }\n        }\n    }\n}<\/code><\/pre>\n\n\n\n<h4>5.3.2.4 \u524d\u7aef\u63a7\u5236\u7c7b<\/h4>\n\n\n\n<ul><li>action\uff1a\u8d1f\u8d23\u63a5\u6536\u7528\u6237\u7684\u6570\u636e\uff0c\u5e76\u4e14\u5c01\u88c5\u5230\u5b9e\u4f53\u7c7b\u5bf9\u8c61\u4e2d<\/li><li>\u524d\u7aef<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>import java.util.Scanner;\n\npublic class StudentAction {\n\n    \/\/\u4f9d\u8d56\u4e8e\u4e1a\u52a1\u5c42\n    private  StudentService service = new StudentService();\n\n    \/\/\u4fdd\u5b58\u5b66\u751f\n    public void saveStudent(Scanner scanner){\n        \/\/\u521b\u5efa\u5bf9\u8c61\n        Student student = new Student();\n        student.setId(StudentUtils.getKetInt());\n        System.out.println(\"\u8bf7\u8f93\u5165\u59d3\u540d\");\n        student.setUsername(scanner.next());\n        System.out.println(\"\u8bf7\u8f93\u5165\u6027\u522b\");\n        student.setSex(scanner.next());\n        System.out.println(\"\u8bf7\u8f93\u5165\u5e74\u9f84\");\n        student.setAge(scanner.nextInt());\n        service.save(student);\n        \/\/\u63d0\u793a\n        System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n    }\n    \/\/\u663e\u793a\u5b66\u751f\n    public void show(){\n        service.findAll();\n    }\n\n    \/\/\u5220\u9664\u5b66\u751f\n    public void deleteStudent(Scanner scanner){\n        System.out.println(\"\u8bf7\u8f93\u5165\u5b66\u53f7\");\n        service.delete(scanner.nextInt());\n    }\n    \/\/\u66f4\u65b0\u5b66\u751f\n    public void updateStudent(Scanner scanner){\n        \/\/\u63d0\u793a\n        System.out.println(\"\u8bf7\u8f93\u5165\u5b66\u53f7\");\n        Student student = new Student();\n        student.setId(scanner.nextInt());\n        System.out.println(\"\u8bf7\u8f93\u5165\u65b0\u59d3\u540d\");\n        student.setUsername(scanner.next());\n        System.out.println(\"\u8bf7\u8f93\u5165\u65b0\u6027\u522b\");\n        student.setSex(scanner.next());\n        System.out.println(\"\u8bf7\u8f93\u5165\u65b0\u5e74\u9f84\");\n        student.setAge(scanner.nextInt());\n        \/\/\u8c03\u7528\u66f4\u65b0\n        service.update(student);\n        System.out.println(\"\u64cd\u4f5c\u6210\u529f\");\n    }\n}<\/code><\/pre>\n\n\n\n<h4>5.3.2.5 \u5de5\u5177\u7c7b<\/h4>\n\n\n\n<ul><li>\u63d0\u4f9b\u4e00\u4e2a\u4e0d\u91cd\u590d\u7684id<\/li><li>\u63d0\u4f9b\u4e00\u4e2a\u65e5\u671f<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>import java.time.LocalDateTime;\nimport java.util.UUID;\nimport java.util.zip.CRC32;\n\npublic class StudentUtils {\n    \/\/\u6784\u9020\u65b9\u6cd5\u79c1\u6709\u5316\n    private StudentUtils(){}\n\n    \/\/\u9759\u6001\u65b9\u6cd5\n    public static String getKetString(){\n        return UUID.randomUUID().toString();\n    }\n    \/\/\u9759\u6001\u65b9\u6cd5\n    public static int getKetInt(){\n        CRC32 crc32 = new CRC32();\n        crc32.update(UUID.randomUUID().toString().getBytes());\n        long value = crc32.getValue();\n\n        \/\/\u8f6c\u6362\n        return (int) value;\n    }\n\n    \/\/\u65e5\u671f\n    public static String getDateString(){\n        return LocalDateTime.now().toString();\n    }\n}<\/code><\/pre>\n\n\n\n<h4>5.3.2.6 \u524d\u7aef\u7c7b<\/h4>\n\n\n\n<ul><li>\u524d\u7aef<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>import java.util.Scanner;\n\npublic class StudentFront {\n    public static void main(String&#91;] args){\n        \/\/\u4f9d\u8d56\u4e8eaction\u5c42\n        StudentAction action = new StudentAction();\n        \/\/\u63a7\u5236\u53f0\n        Scanner scanner = new Scanner(System.in);\n        \/\/\u5faa\u73af\n        boolean isRunning = true;\n        System.out.println(\"1\u6dfb\u52a0;2\u663e\u793a;3\u5220\u9664;4\u66f4\u65b0;5\u9000\u51fa;\");\n        do{\n            int key = scanner.nextInt();\n            switch(key){\n                case 1:\n                    action.saveStudent(scanner);\n                case 2:\n                    action.show();\n                    break;\n                case 3:\n                    action.deleteStudent(scanner);\n                    break;\n                case 4:\n                    action.updateStudent(scanner);\n                    break;\n                case 5:\n                    isRunning = false;\n                    break;\n            }\n        }while(isRunning);\n    }\n}<\/code><\/pre>\n\n\n\n<h2>5.4 \u7c7b\u7684\u7ee7\u627f<\/h2>\n\n\n\n<h3>5.4.1 \u7ee7\u627f\uff1a<\/h3>\n\n\n\n<ul><li>\u5b9e\u73b0\u4e86\u4ee3\u7801\u91cd\u7528\u7387\uff1b\u4f8b\u5982\uff1aA\u7ee7\u627fB\uff0c\u90a3\u4e48\uff0cA\u5c31\u62e5\u6709B\u7684\u6240\u6709\u7279\u6027\uff1b<\/li><li>java\u4e2d\u7684\u7c7b\u662f\u5355\u7ee7\u627f\u6027<\/li><li>\u7ee7\u627f\u7684\u5173\u952e\u5b57extends<\/li><li>\u7ee7\u627f\u4f18\u5148<\/li><li>\u6848\u4f8b\uff1aclass A extends B{}<\/li><\/ul>\n\n\n\n<h2>5.4.2 \u4ee3\u7801\u91cd\u7528\u7387<\/h2>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        Student student = new Student();\n        \/\/\u53ef\u4ee5\u76f4\u63a5\u8c03\u7528\u7236\u7c7b\u5bf9\u8c61\u7684\u65b9\u6cd5\n        student.setAge(11);\n    }\n}\n\nclass Student extends Person{\n    private int sid;\n\n    public int getSid() {\n        return sid;\n    }\n\n    public void setSid(int sid) {\n        this.sid = sid;\n    }\n}\n\nclass User extends Person{\n    private int sid;\n\n\n    public int getSid() {\n        return sid;\n    }\n\n    public void setSid(int sid) {\n        this.sid = sid;\n    }\n}\n\nclass Person{\n    private String username;\n    private String sex;\n    private int age;\n\n    public String getUsername() {\n        return username;\n    }\n\n    public void setUsername(String username) {\n        this.username = username;\n    }\n\n    public String getSex() {\n        return sex;\n    }\n\n    public void setSex(String sex) {\n        this.sex = sex;\n    }\n\n    public int getAge() {\n        return age;\n    }\n\n    public void setAge(int age) {\n        this.age = age;\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u5f53\u521b\u5efa\u5b50\u7c7b\u5bf9\u8c61\u65f6\uff0c\u7236\u7c7b\u5bf9\u8c61\u5148\u88ab\u521b\u5efa\u51fa\u6765(\u65e0\u7236\u5373\u65e0\u5b50)\uff0c\u5b50\u7c7b\u4f1a\u9ed8\u8ba4\u521b\u5efa\u7236\u7c7b\u7684\u6784\u9020\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        Student student = new Student();\n    }\n}\nclass Student extends Person{\n\n    public Student(){\n        System.out.println(\"\u5b50\u7c7b\u6784\u9020\u65b9\u6cd5\");\n    }\n}\n\nclass Person{\n    public Person(){\n        System.out.println(\"\u7236\u7c7b\u6784\u9020\u65b9\u6cd5\");\n    }\n}<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-8.png\" alt=\"\" class=\"wp-image-735\" width=\"839\" height=\"207\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-8.png 770w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-8-300x74.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-8-768x190.png 768w\" sizes=\"(max-width: 839px) 100vw, 839px\" \/><\/figure>\n\n\n\n<h3>5.4.3 \u7c7b\u7684\u91cd\u5199(\u8986\u76d6)-\u90fd\u662f\u5bf9\u65b9\u6cd5<\/h3>\n\n\n\n<ul><li>\u91cd\u8f7d<ul><li>\u5728\u540c\u4e00\u4e2a\u7c7b\u4e2d<\/li><li>\u65b9\u6cd5\u540d\u79f0\u76f8\u540c<\/li><li>\u53ea\u8ddf\u65b9\u6cd5\u7684\u53c2\u6570\uff1a\u4e2a\u6570\u3001\u987a\u5e8f\u3001\u7c7b\u578b\u4e0d\u540c\u5373\u53ef<\/li><li>\u4e0e\u65b9\u6cd5\u7684\u4fee\u9970\u7b26\u548c\u8fd4\u56de\u7c7b\u578b\u65e0\u5173<\/li><\/ul><\/li><li>\u91cd\u5199<ul><li>\u5fc5\u987b\u662f\u5b50\u7c7b\u548c\u7236\u7c7b\u6709\u7ee7\u627f\u5173\u7cfb<\/li><li>\u8986\u76d6\u53ea\u80fd\u51fa\u73b0\u5728\u5b50\u7c7b\u4e2d<\/li><li>\u5728\u5b50\u7c7b\u4e2d\u88ab\u8986\u76d6\u7684\u65b9\u6cd5\uff0c\u5fc5\u987b\u4e0e\u7236\u7c7b\u7684\u65b9\u6cd5\"\u5b8c\u5168\"\u4e00\u6837\uff0c\u4e5f\u5c31\u662f\u8bf4\u65b9\u6cd5\u540d\u79f0\u3001\u8fd4\u56de\u7c7b\u578b\u3001\u65b9\u6cd5\u53c2\u6570\uff0c\u8981\u5b8c\u5168\u4e00\u81f4<\/li><li>\u5b50\u7c7b\u65b9\u6cd5\u7684\u8bbf\u95ee\u6743\u9650\u4e0d\u80fd\u5c0f\u4e8e\u7236\u7c7b\u65b9\u6cd5\u7684\u8bbf\u95ee\u6743\u9650<\/li><li>\u5b50\u7c7b\u4e0d\u80fd\u629b\u51fa\u6bd4\u7236\u7c7b\u66f4\u591a\u7684\u5f02\u5e38\uff0c\u4f46\u662f\uff0c\u53ef\u4ee5\u629b\u51fa\u7236\u7c7b\u5f02\u5e38\u7684\u5b50\u5f02\u5e38<\/li><li>\u7236\u7c7b\u7684\u9759\u6001\u65b9\u6cd5\u4e0d\u80fd\u88ab\u5b50\u7c7b\u8986\u76d6<\/li><li>\u7236\u7c7b\u7684\u79c1\u6709\u65b9\u6cd5\u4e5f\u4e0d\u80fd\u88ab\u8986\u76d6<\/li><li>\u8986\u76d6\u9488\u5bf9\u7684\u662f\"\u65b9\u6cd5\"\u800c\u975e\"\u5c5e\u6027\"<\/li><li>\u91cd\u5199\u5c31\u662f\u6539\u53d8\u4e86\u7236\u7c7b\u7684\u884c\u4e3a<\/li><\/ul><\/li><\/ul>\n\n\n\n<h4>5.4.3.1 \u6848\u4f8b\uff1a<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        Animal cat = new Cat();\n        cat.move();\n    }\n}\n\nclass Animal {\n    public void move(){\n        System.out.println(\"\u52a8\u7269\u79fb\u52a8\");\n    }\n}\n\nclass Cat extends Animal{\n    public void move(){\n        System.out.println(\"\u5c0f\u732b\u5728\u79fb\u52a8..\");\n    }\n}<\/code><\/pre>\n\n\n\n<p>\u901a\u8fc7\u4e0a\u9762\u7684\u4f8b\u5b50\uff0c\u53ef\u4ee5\u770b\u5230\uff0c\u7236\u7c7b\u6307\u5411\u5b50\u7c7b\u7684\u5f15\u7528\uff0c\u5b50\u7c7b\u6539\u53d8\u4e86\u7236\u7c7b\u7684\u884c\u4e3a<\/p>\n\n\n\n<p>\u591a\u6001\u5c31\u662f\u591a\u79cd\u5f62\u6001\uff0coverload(\u91cd\u8f7d)\u662f\u591a\u6001\u7684\u4e00\u79cd\uff0c\u5c5e\u4e8e\u7f16\u8bd1\u671f\u7ed1\u5b9a\uff1boverride(\u91cd\u5199)\u662f\u8fd0\u884c\u671f\u95f4\u7ed1\u5b9a\u7684(\u540e\u671f\u7ed1\u5b9a)<\/p>\n\n\n\n<p>\u591a\u6001\u5b58\u5728\u7684\u6761\u4ef6\uff1a<\/p>\n\n\n\n<ol><li>\u6709\u7ee7\u627f<\/li><li>\u6709\u8986\u76d6<\/li><li>\u7236\u7c7b\u6307\u5411\u5b50\u7c7b\u7684\u5f15\u7528<\/li><\/ol>\n\n\n\n<h4>5.4.3.2 \u5bf9\u9759\u6001\u65b9\u6cd5\u8986\u76d6<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        Animal cat = new Cat();\n        cat.move();\n    }\n}\n\nclass Animal {\n    public static void move(){\n        System.out.println(\"\u52a8\u7269\u79fb\u52a8\");\n    }\n}\n\nclass Cat extends Animal{\n    public static void move(){\n        System.out.println(\"\u5c0f\u732b\u5728\u79fb\u52a8..\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u9759\u6001\u65b9\u6cd5\u4e0d\u4ea7\u751f\u8986\u76d6<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-9.png\" alt=\"\" class=\"wp-image-736\" width=\"840\" height=\"582\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-9.png 809w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-9-300x208.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-9-768x533.png 768w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><\/figure>\n\n\n\n<h4>5.4.3.3 \u6210\u5458\u65b9\u6cd5\u53ef\u4ee5\u88ab\u8986\u76d6\uff0c\u4f46\u662f\u6210\u5458\u53d8\u91cf\u4e0d\u80fd\u88ab\u8986\u76d6<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        Animal cat = new Cat();\n        cat.move();\n        System.out.println(cat.name);\n    }\n}\n\nclass Animal {\n    public String name = \"\u52a8\u7269\";\n    public void move(){\n        System.out.println(\"\u52a8\u7269\u79fb\u52a8\");\n    }\n}\n\nclass Cat extends Animal{\n    public String name = \"\u52a8\u7269\";\n    public void move(){\n        System.out.println(\"\u5c0f\u732b\u5728\u79fb\u52a8..\");\n    }\n}<\/code><\/pre>\n\n\n\n<h2>5.5 super\u5173\u952e\u5b57<\/h2>\n\n\n\n<h3>5.5.1 \u4f5c\u7528<\/h3>\n\n\n\n<ul><li>super\u6307\u7684\u662f\u7236\u7c7b\u5bf9\u8c61<\/li><li><strong>\u8c03\u7528\u7236\u7c7b\u7684\u6784\u9020\u65b9\u6cd5<\/strong><\/li><li>\u8c03\u7528\u7236\u7c7b\u7684\u6210\u5458\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<p><strong>\u6ce8\u610f<\/strong>\uff1asuper\u53ea\u80fd\u5e94\u7528\u4e8e\u6210\u5458\u65b9\u6cd5\u548c\u6784\u9020\u65b9\u6cd5\u4e2d\uff0c\u4e0d\u80fd\u5e94\u7528\u5728static\u9759\u6001\u65b9\u6cd5\u4e2d\uff0c\u5982\u679c\u5728\u6784\u9020\u65b9\u6cd5\u4e2d\u4f7f\u7528(\u548cthis\u76f8\u540c)\u5fc5\u987b\u653e\u5728\u9996\u884c\u3002<\/p>\n\n\n\n<h3>5.5.2 \u4e3a\u4ec0\u4e48\u4f1a\u6709super\u5173\u952e\u5b57<\/h3>\n\n\n\n<ul><li>\u56e0\u4e3a\u5b50\u7c7b\u521b\u5efa\u5bf9\u8c61\u65f6\u5fc5\u987b\u8c03\u7528\u7236\u7c7b\u7684\u6784\u9020\u65b9\u6cd5\uff0c\u5148\u628a\u7236\u7c7b\u6784\u9020\u5b8c\u6210\uff0c\u56e0\u4e3a\u5b50\u7c7b\u4f9d\u8d56\u4e8e\u7236\u7c7b\uff1b\u65e0\u7236\u5373\u65e0\u5b50\uff1b<\/li><li>\u5b50\u7c7b\u6709\u65f6\u4e5f\u8c03\u7528\u7236\u7c7b\u7684\u6210\u5458\u65b9\u6cd5\uff1b<\/li><li><strong>\u7279\u6b8a\u6ce8\u610f<\/strong>\uff1a\u6211\u4eec\u5728\u5f88\u591a\u7684\u65f6\u5019\u521b\u5efa\u5b50\u7c7b\u5bf9\u8c61\u65f6\uff0c\u5e76\u4e0d\u663e\u793a\u7684\u7f16\u5199\u6784\u9020\u65b9\u6cd5\u7684\uff0c\u90a3\u4e48\uff0c\u9ed8\u8ba4\u8c03\u7528\u7684\u5c31\u662f\u7236\u7c7b\u7684\u65e0\u53c2\u6570\u6784\u9020\u65b9\u6cd5<\/li><li><strong>\u7279\u522b\u6ce8\u610f<\/strong>\uff1a\u6784\u9020\u65b9\u6cd5\u53ef\u4ee5\u88ab\u91cd\u8f7d\uff0c\u4e0d\u53ef\u4ee5\u88ab\u91cd\u5199<\/li><\/ul>\n\n\n\n<h3>5.5.3 \u6848\u4f8b\uff1a<\/h3>\n\n\n\n<h4>5.5.3.1 \u8c03\u7528\u7236\u7c7b\u7684\u9ed8\u8ba4\u6784\u9020\u65b9\u6cd5<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u521b\u5efa\u5b50\u7c7b\u5bf9\u8c61\n        Emp emp = new Emp();\n    }\n}\n\nclass Person{\n    public Person(){\n        System.out.println(\"\u7236\u7c7b\u7684\u65e0\u53c2\u6570\u6784\u9020\u65b9\u6cd5\");\n    }\n}\n\nclass Emp extends Person{\n    public Emp(){\n        \/\/super();\n        System.out.println(\"\u5b50\u7c7b\u7684\u65e0\u53c2\u6570\u6784\u9020\u65b9\u6cd5\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u5148\u521b\u5efa\u7236\u7c7b\u5bf9\u8c61\u7136\u540e\u521b\u5efa\u5b50\u7c7b\u5bf9\u8c61<\/li><\/ul>\n\n\n\n<h4>5.5.3.2 \u8c03\u7528\u6307\u5b9a\u7684\u6784\u9020\u65b9\u6cd5<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u521b\u5efa\u5b50\u7c7b\u5bf9\u8c61\n        Emp emp = new Emp();\n    }\n}\n\nclass Person{\n    \/\/\u6784\u9020\u65b9\u6cd5\u91cd\u8f7d\n    public Person(){\n        System.out.println(\"\u7236\u7c7b\u7684\u65e0\u53c2\u6570\u6784\u9020\u65b9\u6cd5\");\n    }\n    public Person(int i){\n        System.out.println(\"\u7236\u7c7b1\u53c2\u6570\u6784\u9020\u65b9\u6cd5\");\n    }\n    public Person(int i,int n){\n        System.out.println(\"\u7236\u7c7b2\u53c2\u6570\u6784\u9020\u65b9\u6cd5\");\n    }\n\n}\n\nclass Emp extends Person{\n    public Emp(){\n        super(1,2);\n        System.out.println(\"\u5b50\u7c7b\u7684\u65e0\u53c2\u6570\u6784\u9020\u65b9\u6cd5\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u8c03\u7528\u7236\u7c7b\u76842\u4e2a\u53c2\u6570\u7684\u6784\u9020\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<h4>5.5.3.3 \u7b14\u8bd5\u9898<\/h4>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"1024\" height=\"390\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-10-1024x390.png\" alt=\"\" class=\"wp-image-746\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-10-1024x390.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-10-300x114.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-10-768x292.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-10.png 1190w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h4>5.5.3.4 \u7b14\u8bd5\u9898<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u521b\u5efa\u5b50\u7c7b\u5bf9\u8c61\n        Emp emp = new Emp(10);\n    }\n}\n\nclass Person{\n    \/\/\u6784\u9020\u65b9\u6cd5\u91cd\u8f7d\n    public Person(){\n        System.out.println(1);\n    }\n\n    public Person(int i){\n        System.out.println(2);\n    }\n\n    static{\n        System.out.println(3);\n    }\n\n    {\n        System.out.println(4);\n    }\n\n}\n\nclass Emp extends Person{\n    public Emp(){\n        System.out.println(5);\n    }\n\n    public Emp(int i){\n        System.out.println(6);\n    }\n\n    static{\n        System.out.println(7);\n    }\n\n    {\n        System.out.println(8);\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u8f93\u51fa\uff1a374186<\/li><\/ul>\n\n\n\n<h2>5.6 final<\/h2>\n\n\n\n<ul><li>final\u8868\u793a\u6700\u7ec8\u7684\uff0c\u4e0d\u80fd\u6539\u53d8\u7684<\/li><\/ul>\n\n\n\n<h3>5.6.1 \u4fee\u9970<\/h3>\n\n\n\n<ul><li>\u91c7\u7528final\u4fee\u9970\u7684\u7c7b\u4e0d\u80fd\u88ab\u7ee7\u627f\u4e86<\/li><li>\u91c7\u7528final\u4fee\u9970\u7684\u53d8\u91cf\uff1a<ul><li>\u57fa\u672c\u7c7b\u578b\uff1a\u53d8\u91cf\u7684\u503c\u4e0d\u80fd\u6539\u53d8<\/li><li>\u5f15\u7528\u7c7b\u578b\uff1a\u5f15\u7528\u7684\u5730\u5740\u4e0d\u80fd\u6539\u53d8\uff0c\u4f46\u662f\u88ab\u6307\u5411\u7684\u5bf9\u8c61\u4e2d\u7684\u5c5e\u6027\u662f\u53ef\u4ee5\u4fee\u6539\u7684<\/li><\/ul><\/li><li>\u91c7\u7528final\u4fee\u9970\u7684\u65b9\u6cd5\u4e0d\u80fd\u88ab\u8986\u76d6\u4e86<\/li><li>\u91c7\u7528final\u4fee\u9970\u7684\u53d8\u91cf\u5fc5\u987b\u663e\u793a\u521d\u59cb\u5316<\/li><li>\u6784\u9020\u65b9\u6cd5\u4e0d\u80fd\u88abfinal\u4fee\u9970<\/li><li>\u4f7f\u7528static final\u4fee\u9970\u7684\u662f\"\u5e38\u91cf\"\uff0c\u540d\u79f0\u8981\u6c42\"\u5168\u90e8\"\u5927\u5199<\/li><\/ul>\n\n\n\n<h3>5.6.2 \u6848\u4f8b\uff1a<\/h3>\n\n\n\n<h4>5.6.2.1 final\u7684\u7c7b\u4e0d\u80fd\u88ab\u7ee7\u627f<\/h4>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-12.png\" alt=\"\" class=\"wp-image-756\" width=\"842\" height=\"299\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-12.png 698w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-12-300x107.png 300w\" sizes=\"(max-width: 842px) 100vw, 842px\" \/><\/figure>\n\n\n\n<h4>5.6.2.2 final\u4fee\u9970\u7684\u65b9\u6cd5\u4e0d\u80fd\u88ab\u8986\u76d6<\/h4>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-11.png\" alt=\"\" class=\"wp-image-755\" width=\"840\" height=\"406\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-11.png 702w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-11-300x145.png 300w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><\/figure>\n\n\n\n<h4>5.6.2.3 final\u4fee\u9970\u57fa\u672c\u7c7b\u578b\u53d8\u91cf<\/h4>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-13.png\" alt=\"\" class=\"wp-image-757\" width=\"841\" height=\"278\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-13.png 809w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-13-300x99.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-13-768x253.png 768w\" sizes=\"(max-width: 841px) 100vw, 841px\" \/><\/figure>\n\n\n\n<ul><li>\u5e38\u91cf<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-14.png\" alt=\"\" class=\"wp-image-758\" width=\"840\" height=\"137\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-14.png 706w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-14-300x49.png 300w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><\/figure>\n\n\n\n<ul><li>\u5fc5\u987b\u521d\u59cb\u5316<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-15.png\" alt=\"\" class=\"wp-image-759\" width=\"840\" height=\"170\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-15.png 753w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-15-300x61.png 300w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><\/figure>\n\n\n\n<h4>5.6.2.4 final\u4fee\u9970\u5f15\u7528\u7c7b\u578b\u5730\u5740\u4e0d\u80fd\u88ab\u6539\u53d8<\/h4>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" width=\"886\" height=\"579\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-16.png\" alt=\"\" class=\"wp-image-760\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-16.png 886w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-16-300x196.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-16-768x502.png 768w\" sizes=\"(max-width: 886px) 100vw, 886px\" \/><\/figure>\n\n\n\n<ul><li>\u53ef\u4ee5\u4fee\u6539\u5bf9\u8c61\u4e2d\u5c5e\u6027<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        final Person person = new Person();\n        \/\/\u4fee\u6539\u5c5e\u6027\n        person.setUsername(\"\u5f20\u4e09\");\n        person.setUsername(\"\u674e\u56db\");\n    }\n}\n\nclass Person{\n    private String username;\n\n    public String getUsername() {\n        return username;\n    }\n\n    public void setUsername(String username) {\n        this.username = username;\n    }\n}<\/code><\/pre>\n\n\n\n<h2>5.7 \u62bd\u8c61\u7c7b<\/h2>\n\n\n\n<ul><li>\u91cd\u70b9\uff1a\u62bd\u8c61\u7c7b\u4e0d\u80fd\u521b\u5efa\u5bf9\u8c61\uff0c\u4f46\u662f\uff0c\u6709\u6784\u9020\u65b9\u6cd5\u56e0\u4e3a\u5b50\u7c7b\u5728\u521b\u5efa\u5bf9\u8c61\u65f6\u5fc5\u987b\u8c03\u7528\u7236\u7c7b\u7684\u6784\u9020\u65b9\u6cd5\u3002<\/li><\/ul>\n\n\n\n<h3>5.7.1 \u62bd\u8c61\u7c7b<\/h3>\n\n\n\n<ul><li>\u4f7f\u7528abstract\u4fee\u9970\u7684\u7c7b\u5373\u4e3a\u62bd\u8c61\u7c7b<\/li><li>\u4f7f\u7528abstract\u4fee\u9970\u7684\u65b9\u6cd5\u5373\u4e3a\u62bd\u8c61\u65b9\u6cd5<\/li><li>\u62bd\u8c61\u7c7b\u4e2d\u53ef\u4ee5\u6709\u62bd\u8c61\u65b9\u6cd5\u4e5f\u53ef\u4ee5\u6ca1\u6709<\/li><li>\u5982\u679c\u7c7b\u4e2d\u6709\u62bd\u8c61\u65b9\u6cd5\uff0c\u90a3\u4e48\u8fd9\u4e2a\u7c7b\u4e00\u5b9a\u662f\u62bd\u8c61\u7c7b<\/li><li>\u62bd\u8c61\u65b9\u6cd5\u4e0d\u80fd\u4f7f\u7528final\u4fee\u9970<\/li><li>\u5b50\u7c7b\u7ee7\u627f\u4e86\u62bd\u8c61\u7c7b\uff0c\u90a3\u4e48\u5fc5\u987b\u5b9e\u73b0\u6240\u6709\u7684\u62bd\u8c61\u65b9\u6cd5<\/li><li>\u5982\u679c\u5b50\u7c7b\u7ee7\u627f\u4e86\u62bd\u8c61\u7236\u7c7b\uff0c\u5e76\u4e14\uff0c\u6ca1\u6709\u5b9e\u73b0\u62bd\u8c61\u65b9\u6cd5\uff0c\u90a3\u4e48\u8fd9\u4e2a\u5b50\u7c7b\u4e5f\u4e00\u5b9a\u662f\u4e00\u4e2a\u62bd\u8c61\u7c7b<\/li><\/ul>\n\n\n\n<h3>5.7.2 \u62bd\u8c61\u7c7b\u7684\u4f5c\u7528<\/h3>\n\n\n\n<ul><li>\u5728\u62bd\u8c61\u7c7b\u4e2d\u53ef\u4ee5\u6dfb\u52a0\u516c\u7528\u7684\u4ee3\u7801(\u5c31\u662f\u76f8\u540c\u7684\u4ee3\u7801)<\/li><li>\u5728\u62bd\u8c61\u7c7b\u4e2d\u53ef\u4ee5\u7ea6\u675f<\/li><\/ul>\n\n\n\n<h3>5.7.3 \u6848\u4f8b\uff1a<\/h3>\n\n\n\n<h4>5.7.3.1 \u62bd\u8c61\u7236\u7c7b<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        new Emp();\n    }\n}\n\nabstract class Person{\n    private int id;\n    private String username;\n\n    public Person(){\n        System.out.println(\"------------>>\");\n    }\n    public Person(int i){}\n\n    public int getId() {\n        return id;\n    }\n\n    public void setId(int id) {\n        this.id = id;\n    }\n\n    public String getUsername() {\n        return username;\n    }\n\n    public void setUsername(String username) {\n        this.username = username;\n    }\n}\n\nclass Emp extends Person{}<\/code><\/pre>\n\n\n\n<ul><li>\u5b50\u7c7b\u521b\u5efa\u5bf9\u8c61\u65f6\u4e5f\u8c03\u7528\u4e86\u7236\u7c7b\u7684\u6784\u9020\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<h4>5.7.3.2 \u5728\u62bd\u8c61\u7236\u7c7b\u4e2d\u6dfb\u52a0\u7ea6\u675f<\/h4>\n\n\n\n<ul><li>\u6dfb\u52a0\u4e00\u4e2a\u62bd\u8c61\u65b9\u6cd5\uff0c\u5b50\u7c7b\u5fc5\u987b\u8981\u5b9e\u73b0<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>abstract class Person{\n    \/\/\u62bd\u8c61\u65b9\u6cd5\n    public abstract void show();\n    public abstract void save();\n    \/\/\u5b9e\u73b0\u7684\u65b9\u6cd5\n    public void update(){\n        System.out.println(\"\u5b9e\u73b0\u7684\u65b9\u6cd5\");\n    }\n}\n\nclass Emp extends Person{\n    @Override\n    public void show() {\n        System.out.println(\"\u5fc5\u987b\u5b9e\u73b0\u62bd\u8c61\u65b9\u6cd5\");\n    }\n\n    @Override\n    public void save() {\n        System.out.println(\"\u5fc5\u987b\u5b9e\u73b0\u62bd\u8c61\u65b9\u6cd5\");\n    }\n}<\/code><\/pre>\n\n\n\n<h4>5.7.3.3 \u62bd\u8c61\u7236\u7c7b\u4e0d\u80fd\u4f7f\u7528final\u4fee\u9970<\/h4>\n\n\n\n<ul><li>\u56e0\u4e3a\u8fd9\u6837\u5f88\u77db\u76fe\uff08\u8fd9\u4e24\u4e2a\u5173\u952e\u5b57\uff09<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-17.png\" alt=\"\" class=\"wp-image-761\" width=\"838\" height=\"370\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-17.png 741w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-17-300x132.png 300w\" sizes=\"(max-width: 838px) 100vw, 838px\" \/><\/figure>\n\n\n\n<h4>5.7.3.4 \u62bd\u8c61\u65b9\u6cd5\u4e0d\u80fd\u4f7f\u7528final\u4fee\u9970<\/h4>\n\n\n\n<ul><li>\u56e0\u4e3a\u8fd9\u6837\u5f88\u77db\u76fe\uff08\u8fd9\u4e24\u4e2a\u5173\u952e\u5b57\uff09<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"1024\" height=\"348\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-18-1024x348.png\" alt=\"\" class=\"wp-image-762\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-18-1024x348.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-18-300x102.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-18-768x261.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-18.png 1108w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h4>5.7.3.5 \u62bd\u8c61\u7c7b\u4e2d\u7684\u62bd\u8c61\u65b9\u6cd5\u6ca1\u6709\u88ab\u5b9e\u73b0\uff0c\u90a3\u4e48\uff0c\u5b50\u7c7b\u4e5f\u662f\u62bd\u8c61\u7c7b<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        new Emp();\n    }\n}\n\nabstract class Person{\n    \/\/\u62bd\u8c61\u65b9\u6cd5\n    public abstract void show();\n}\n\nabstract class Emp extends Person{\n   public abstract void save();\n}\n\/\/\u6700\u7ec8\u7684\u5b50\u7c7b\u5fc5\u987b\u5b9e\u73b0\u6240\u6709\u7684\u62bd\u8c61\u65b9\u6cd5\nclass User extends Emp{\n\n    @Override\n    public void show() {\n        \n    }\n\n    @Override\n    public void save() {\n\n    }\n}<\/code><\/pre>\n\n\n\n<h2>5.8 \u63a5\u53e3<\/h2>\n\n\n\n<ul><li>\u63a5\u53e3\u5c31\u662f\u6807\u51c6\uff0c\u5173\u952e\u5b57\u662finterface<\/li><li>\u9762\u5411\u62bd\u8c61\u7f16\u7a0b\uff0c\u5c31\u662f\u9762\u5411\u63a5\u53e3\u7f16\u7a0b<\/li><\/ul>\n\n\n\n<h3>5.8.1 \u63a5\u53e3\u5206\u7c7b<\/h3>\n\n\n\n<h4>5.8.1.1 \u666e\u901a\u63a5\u53e3\uff1a<\/h4>\n\n\n\n<ul><li>\u63a5\u53e3\u4e2d\u7684\u65b9\u6cd5\u90fd\u662fpublic abstract<\/li><li>\u63a5\u53e3\u4e2d\u7684\u65b9\u6cd5\u53ef\u4ee5\u5b9e\u73b0<\/li><li>\u63a5\u53e3\u4e2d\u7684\u7684\u53d8\u91cf\u90fd\u662f\u5e38\u91cfpublic static final<\/li><li>\u63a5\u53e3\u4e0d\u80fd\u5b9e\u4f8b\u5316\uff0c\u63a5\u53e3\u4e2d\u6ca1\u6709\u6784\u9020\u65b9\u6cd5\u7684\u6982\u5ff5<\/li><li>\u63a5\u53e3\u95f4\u53ef\u4ee5\u5b9e\u73b0\u591a\u7ee7\u627f\uff0c\u4f46\u662f\uff0c\u63a5\u53e3\u4e4b\u95f4\u4e0d\u80fd\u5b9e\u73b0<\/li><li>\u5b9e\u73b0\u63a5\u53e3\u7684\u5173\u952e\u5b57implements<\/li><li>\u7c7b\u53ef\u4ee5\u5b9e\u73b0\u591a\u4e2a\u63a5\u53e3\uff0c\u5e76\u4e14\uff0c\u9700\u8981\u5b9e\u73b0\u63a5\u53e3\u4e2d\u6240\u6709\u7684\u62bd\u8c61\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<h4>5.8.1.2 \u51fd\u6570\u5f0f\u63a5\u53e3\uff1a<\/h4>\n\n\n\n<ul><li>\u4f7f\u7528\u6807\u7b7e\uff1aFunctionInterface\u4fee\u9970\u7684<\/li><li>\u63a5\u53e3\u4e2d\u53ef\u4ee5\u6709\u5b9e\u73b0\u7684\u65b9\u6cd5\u4e86<\/li><li>\u63a5\u53e3\u4e2d\u53ea\u80fd\u6709\u4e14\u53ea\u6709\u4e00\u4e2a\u5fc5\u987b\u5b9e\u73b0\u7684\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<h3>5.8.2 \u521b\u5efa\u63a5\u53e3<\/h3>\n\n\n\n<h4>5.8.2.1 \u7f16\u5199\u63a5\u53e3<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public interface StudentManager {\n    public abstract void save();\n    public static final int ABC = 100;\n    \/\/\u5b9e\u73b0\u7684\u65b9\u6cd5:\u4f7f\u7528default\u5173\u952e\u5b57\u5c31\u662f\u8ba9\u4f60\u6765\u8986\u76d6\u7684\n    default void delete(){\n        System.out.println(\"\u8fd9\u662f\u4e00\u4e2a\u5220\u9664\u65b9\u6cd5\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u7f16\u5199\u63a5\u53e3\u65f6\u53ef\u4ee5\u7701\u7565public abstarct\u6216\u8005static final<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public interface StudentManager {\n    void save();\n    int ABC = 100;\n}<\/code><\/pre>\n\n\n\n<h4>5.8.2.2 \u63a5\u53e3\u4e2d\u7684\u53d8\u91cf\u90fd\u662f\u5e38\u91cf,\u6240\u4ee5\u4e0d\u80fd\u4fee\u6539<\/h4>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-19.png\" alt=\"\" class=\"wp-image-763\" width=\"838\" height=\"235\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-19.png 650w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-19-300x84.png 300w\" sizes=\"(max-width: 838px) 100vw, 838px\" \/><\/figure>\n\n\n\n<h4>5.8.2.3 \u63a5\u53e3\u4e4b\u95f4\u4e0d\u80fd\u5b9e\u4f8b\u5316<\/h4>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"1024\" height=\"252\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-20-1024x252.png\" alt=\"\" class=\"wp-image-764\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-20-1024x252.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-20-300x74.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-20-768x189.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-20.png 1208w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h4>5.8.2.4 \u63a5\u53e3\u95f4\u53ef\u4ee5\u591a\u7ee7\u627f<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>interface A{\n    void method1();\n}\ninterface B{\n    void method2();\n}\ninterface C extends A,B{}<\/code><\/pre>\n\n\n\n<h4>5.8.2.5 \u63a5\u53e3\u95f4\u4e0d\u80fd\u5b9e\u73b0<\/h4>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-21.png\" alt=\"\" class=\"wp-image-765\" width=\"837\" height=\"217\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-21.png 792w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-21-300x78.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-21-768x199.png 768w\" sizes=\"(max-width: 837px) 100vw, 837px\" \/><\/figure>\n\n\n\n<h4>5.8.2.6 \u63a5\u53e3\u53ea\u80fd\u901a\u8fc7\u7c7b\u5b9e\u73b0\uff0c\u5e76\u4e14\uff0c\u9700\u8981\u5b9e\u73b0\u6240\u6709\u7684\u62bd\u8c61\u65b9\u6cd5<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>interface A{\n    void method1();\n}\ninterface B {\n    void method2();\n}\ninterface C extends A,B{}\n\/\/\u5b9e\u73b0\u63a5\u53e3\nclass CImpl implements C{\n\n    @Override\n    public void method1() {\n\n    }\n\n    @Override\n    public void method2() {\n\n    }\n}<\/code><\/pre>\n\n\n\n<h4>5.8.2.7 \u4e00\u4e2a\u7c7b\u53ef\u4ee5\u540c\u65f6\u5b9e\u73b0\u591a\u4e2a\u63a5\u53e3<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>interface A{\n    void method1();\n}\ninterface B {\n    void method2();\n}\n\/\/\u5b9e\u73b0\u63a5\u53e3\n\nclass CImpl implements A,B{\n\n    @Override\n    public void method1() {\n\n    }\n\n    @Override\n    public void method2() {\n\n    }\n}<\/code><\/pre>\n\n\n\n<h4>5.8.2.8 \u5373\u6709\u7236\u7c7b\u4e5f\u8981\u5b9e\u73b0\u63a5\u53e3\uff0c\u7ee7\u627f\u4f18\u5148<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/\u7236\u7c7b\nclass Person{}\ninterface A{\n    void method1();\n}\ninterface B {\n    void method2();\n}\n\/\/\u5b9e\u73b0\u63a5\u53e3\n\nclass CImpl extends Person implements A,B{\n\n    @Override\n    public void method1() {\n\n    }\n\n    @Override\n    public void method2() {\n\n    }\n}<\/code><\/pre>\n\n\n\n<h4>5.8.2.9 \u7b14\u8bd5\u9898\uff1a\u62bd\u8c61\u7c7b\u53ef\u4ee5\u5b9e\u73b0\u63a5\u53e3<\/h4>\n\n\n\n<ul><li>\u65e0\u975e\u5c31\u662f\u6dfb\u52a0\u63a5\u53e3\u4e2d\u7684\u62bd\u8c61\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>interface A{\n    void show();\n}\n\n\/\/\u7236\u7c7b\nabstract class Person implements A{\n\n}\n\/\/\u5b9e\u73b0\u62bd\u8c61\u65b9\u6cd5\nclass CImpl extends Person{\n    @Override\n    public void show() {\n\n    }\n}<\/code><\/pre>\n\n\n\n<h3>5.8.3 \u63a5\u53e3\u8fdb\u4e00\u6b65\u5e94\u7528<\/h3>\n\n\n\n<h4>5.8.3.1 \u63a5\u53e3\u7684\u672c\u8d28<\/h4>\n\n\n\n<ul><li>\u672c\u8d28\u5c31\u662f\u62bd\u8c61<\/li><li>\u91c7\u7528\u63a5\u53e3\u53ef\u4ee5\u5f88\u660e\u786e\u7684\u58f0\u660e\u4e86\u6240\u63d0\u4f9b\u7684\u670d\u52a1<\/li><li>\u89e3\u51b3\u4e86\u7c7b\u7684\u5355\u7ee7\u627f\u95ee\u9898<\/li><li>\u91cd\u8981\uff1a\u5b9e\u73b0\u4e86\u53ef\u63d2\u62d4\u6027<\/li><\/ul>\n\n\n\n<h4>5.8.3.2 \u5f00\u53d1\u4e00\u4e2a\u7cfb\u7edf\u9700\u8981\u4f7f\u7528\u4e24\u79cd\u6570\u636e\u5e93\uff1amysql\u3001oracle<\/h4>\n\n\n\n<ul><li>\u7b2c\u4e00\u79cd\uff1a\u4e0d\u4f7f\u7528\u63a5\u53e3<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u4f7f\u7528mysql\u6570\u636e\u5e93\n        StudentMysql mysql = new StudentMysql();\n        mysql.add();\n        \n        \/\/\u4f7f\u7528oracle\u6570\u636e\u5e93\n        StudentOracle oracle = new StudentOracle();\n        oracle.save();\n    }\n}\n\n\/\/\u64cd\u4f5cmysql\nclass StudentMysql{\n    public void add(){\n        System.out.println(\"\u4fdd\u5b58\u6570\u636e-mysql\");\n    }\n\n    public void show(){\n        System.out.println(\"\u663e\u793a\u6570\u636e-mysql\");\n    }\n}\n\n\/\/\u64cd\u4f5coracle\nclass StudentOracle{\n    public void save(){\n        System.out.println(\"\u4fdd\u5b58\u6570\u636e-oracle\");\n    }\n\n    public void findAll(){\n        System.out.println(\"\u663e\u793a\u6570\u636e-oracle\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u4ee3\u7801\u4e0d\u80fd\u7075\u6d3b\u4f7f\u7528\uff0c\u5f53\u6211\u4eec\u7684\u9700\u6c42\u6539\u53d8\u4e86\u9700\u8981\u6539\u52a8\u5927\u91cf\u4ee3\u7801\u7684\uff0c\u8fd9\u6837\u4f1a\u5bfc\u81f4\u4ee3\u7801\u91cd\u6784\uff0c\u56e0\u4e3a\u9879\u76ee\u6ca1\u6709\u6269\u5c55\u6027\u3002<\/li><li>\u7b2c\u4e8c\u79cd\uff1a\u4f7f\u7528\u63a5\u53e3<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"1024\" height=\"335\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-22-1024x335.png\" alt=\"\" class=\"wp-image-766\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-22-1024x335.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-22-300x98.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-22-768x251.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-22.png 1228w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u4f7f\u7528mysql\u6570\u636e\u5e93\n        IStudent iStudent = new StudentOracleImpl();\/\/new StudentMysqlImpl();\n        iStudent.save();\n        iStudent.delete();\n        iStudent.update();\n    }\n}\n\n\/\/\u5b9a\u4e49\u6807\u51c6\ninterface IStudent{\n    void save();\n    void delete();\n    void update();\n}\n\n\/\/\u64cd\u4f5cmysql\nclass StudentMysqlImpl implements IStudent{\n    public void save(){\n        System.out.println(\"\u4fdd\u5b58\u6570\u636e-mysql\");\n    }\n\n    public void delete(){\n        System.out.println(\"\u5220\u9664\u6570\u636e-mysql\");\n    }\n\n    public void update(){\n        System.out.println(\"\u66f4\u65b0\u6570\u636e-mysql\");\n    }\n}\n\n\/\/\u64cd\u4f5coracle\nclass StudentOracleImpl implements IStudent{\n    public void save(){\n        System.out.println(\"\u4fdd\u5b58\u6570\u636e-oracle\");\n    }\n\n    public void delete(){\n        System.out.println(\"\u5220\u9664\u6570\u636e-oracle\");\n    }\n\n    public void update(){\n        System.out.println(\"\u66f4\u65b0\u6570\u636e-oracle\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u4f53\u73b0\u4e86\u6269\u5c55\u6027\u548c\u7075\u6d3b\u6027\uff1a<ul><li>\u53ea\u8981\u7b26\u5408\u6807\u51c6\u90fd\u53ef\u4ee5\u968f\u65f6\u66f4\u6362<\/li><li>\u9762\u5411\u63a5\u53e3\u7f16\u7a0b(\u56e0\u4e3a\uff0c\u6211\u4eec\u4ee5\u540e\u505a\u6bcf\u4e00\u4ef6\u4e8b\u60c5\u90fd\u8981\u9075\u5b88\u6807\u51c6\u548c\u89c4\u8303)<\/li><\/ul><\/li><\/ul>\n\n\n\n<h2>5.9 \u7c7b\u4e4b\u95f4\u7684\u5173\u7cfb<\/h2>\n\n\n\n<h3>5.9.1 \u6cdb\u5316\u5173\u7cfb:\u7c7b\u548c\u7c7b\u4e4b\u95f4\u7684\u7ee7\u627f\u53ca\u63a5\u53e3\u4e4b\u95f4\u7684\u7ee7\u627f<\/h3>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-23.png\" alt=\"\" class=\"wp-image-767\" width=\"838\" height=\"640\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-23.png 678w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-23-300x229.png 300w\" sizes=\"(max-width: 838px) 100vw, 838px\" \/><\/figure>\n\n\n\n<h3>5.9.2 \u5b9e\u73b0\u5173\u7cfb\uff1a\u7c7b\u5bf9\u63a5\u53e3\u7684\u5b9e\u73b0<\/h3>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-24.png\" alt=\"\" class=\"wp-image-768\" width=\"840\" height=\"314\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-24.png 717w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-24-300x112.png 300w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><\/figure>\n\n\n\n<h3>5.9.3 \u5173\u8054\u5173\u7cfb\uff1a<\/h3>\n\n\n\n<ul><li>\u7c7b\u4e0e\u7c7b\u4e4b\u95f4\u7684\u8fde\u63a5\uff0c\u4e00\u4e2a\u7c7b\u4f5c\u4e3a\u53e6\u4e00\u4e2a\u7c7b\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\u4f7f\u7528\uff0c\u4f8b\u5982\uff1a\u5b9e\u4f8b\u53d8\u91cf(\u6210\u5458\u5c5e\u6027)<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-25-1024x345.png\" alt=\"\" class=\"wp-image-769\" width=\"840\" height=\"283\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-25-1024x345.png 1024w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-25-300x101.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-25-768x258.png 768w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-25.png 1058w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><\/figure>\n\n\n\n<h3>5.9.4 \u805a\u5408\u5173\u7cfb<\/h3>\n\n\n\n<ul><li>\u805a\u5408\u5173\u7cfb\u662f\u5173\u8054\u5173\u7cfb\u7684\u4e00\u79cd\uff0c\u662f\u8f83\u5f3a\u7684\u4e00\u79cd\u5173\u8054\u5173\u7cfb\uff1b\u4f8b\u5982\uff1a\u6c7d\u8f66\u548c\u8f6e\u80ce\uff0c\u4e00\u4e2a\u4ee3\u8868\u6574\u4f53\uff0c\u4e00\u4e2a\u4ee3\u8868\u5c40\u90e8\uff0c\u4f46\u662f\uff0c\u7b26\u5408\u6c7d\u8f66\u7684\u6807\u51c6\u5373\u53ef\uff0c\u4e0d\u9700\u8981\u6307\u5b9a\u8f6e\u80ce\u7684\u5382\u5bb6<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" width=\"992\" height=\"341\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-26.png\" alt=\"\" class=\"wp-image-770\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-26.png 992w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-26-300x103.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-26-768x264.png 768w\" sizes=\"(max-width: 992px) 100vw, 992px\" \/><\/figure>\n\n\n\n<h3>5.9.5 \u5408\u6210\u5173\u7cfb\uff1a<\/h3>\n\n\n\n<ul><li>\u5408\u6210\u5173\u7cfb\u662f\u5173\u8054\u5173\u7cfb\u7684\u4e00\u79cd\uff0c\u6bd4\u5982\u805a\u5408\u5173\u7cfb\u5f3a\u7684\u4e00\u79cd\u5173\u8054\u5173\u7cfb\uff1b\u4f8b\u5982\uff1a\u4eba\u548c\u56db\u80a2<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" width=\"906\" height=\"357\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-27.png\" alt=\"\" class=\"wp-image-771\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-27.png 906w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-27-300x118.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-27-768x303.png 768w\" sizes=\"(max-width: 906px) 100vw, 906px\" \/><\/figure>\n\n\n\n<h3>5.9.6 \u4f9d\u8d56\u5173\u7cfb\uff1a\u662f\u6bd4\u5173\u8054\u5173\u7cfb\u5f31\u7684\u4e00\u79cd\u5173\u7cfb<\/h3>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" width=\"973\" height=\"336\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-28.png\" alt=\"\" class=\"wp-image-772\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-28.png 973w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-28-300x104.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-28-768x265.png 768w\" sizes=\"(max-width: 973px) 100vw, 973px\" \/><\/figure>\n\n\n\n<h2>6.0 is-a\u3001is-like-a\u3001has-a<\/h2>\n\n\n\n<h3>6.0.1 is-a:\u63a5\u53e3\u4e2d\u6709\u7684\u65b9\u6cd5\uff0c\u7c7b\u4e2d\u5fc5\u987b\u5b9e\u73b0<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>interface A{\n    void method();\n}\n\nclass AImpl implements A{\n\n    @Override\n    public void method() {\n        \n    }\n}<\/code><\/pre>\n\n\n\n<h3>6.0.2 is-like-a:\u63a5\u53e3\u4e2d\u7684\u6709\u7684\u65b9\u6cd5\uff0c\u7c7b\u4e2d\u5fc5\u987b\u5b9e\u73b0\uff0c\u5e76\u4e14\uff0c\u7c7b\u4e2d\u4e5f\u6709\u81ea\u5df1\u7684\u65b9\u6cd5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>interface A{\n    void method();\n}\n\nclass AImpl implements A{\n\n    @Override\n    public void method() {\n\n    }\n    public void method2(){\n        \n    }\n}<\/code><\/pre>\n\n\n\n<h3>6.0.3 has-a:\u4e00\u4e2a\u7c7b\u4f5c\u4e3a\u53e6\u4e00\u4e2a\u7c7b\u7684\u5c5e\u6027\u4f7f\u7528<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>class B{}\n\nclass AImpl{\n    private B b;\n}<\/code><\/pre>\n\n\n\n<h2>6.1 Object\u7c7b<\/h2>\n\n\n\n<ul><li>Object\u7c7b\u662f\u6240\u6709\u7c7b\u7684\u7236\u7c7b(\u57fa\u7c7b\u3001\u8d85\u7c7b)<\/li><li>\u81ea\u5b9a\u4e49\u7c7b\u4e0d\u663e\u793a\u7684\u7ee7\u627fObject\uff0c\u90a3\u4e48\uff0c\u9ed8\u8ba4\u7684\u57fa\u7c7b\u5c31\u662fObject<\/li><\/ul>\n\n\n\n<h3>6.1.1 \u6848\u4f8b<\/h3>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-29.png\" alt=\"\" class=\"wp-image-773\" width=\"841\" height=\"239\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-29.png 686w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-29-300x85.png 300w\" sizes=\"(max-width: 841px) 100vw, 841px\" \/><\/figure>\n\n\n\n<ul><li>\u76f8\u5f53\u4e8e<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-30.png\" alt=\"\" class=\"wp-image-774\" width=\"840\" height=\"231\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-30.png 719w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-30-300x83.png 300w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><\/figure>\n\n\n\n<h3>6.1.2 toString\u65b9\u6cd5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        Person person = new Person();\n        System.out.println(person.toString());\n    }\n}\n\nclass Person{\n    @Override\n    public String toString() {\n        return super.toString();\n    }\n}<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" width=\"867\" height=\"333\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-31.png\" alt=\"\" class=\"wp-image-775\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-31.png 867w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-31-300x115.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-31-768x295.png 768w\" sizes=\"(max-width: 867px) 100vw, 867px\" \/><\/figure>\n\n\n\n<ul><li>\u6e90\u4ee3\u7801<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public String toString() {\n    return getClass().getName() + \"@\" + Integer.toHexString(hashCode());\n}<\/code><\/pre>\n\n\n\n<ul><li><strong>\u6ce8\u610f\uff1a\u5728\u8f93\u51fa\u5bf9\u8c61\u7684\u53c2\u6570\u65f6\u5019\uff0c\u8c03\u7528\u6216\u4e0d\u8c03\u7528toString\u65b9\u6cd5\u9ed8\u8ba4\u90fd\u5728\u6267\u884ctoString\u65b9\u6cd5:<\/strong><\/li><\/ul>\n\n\n\n<p><strong>\"getClass().getName() + \"@\" + Integer.toHexString(hashCode());\"<\/strong><\/p>\n\n\n\n<h4>6.1.2.1 \u6211\u4eec\u5728\u8c03\u7528\u5bf9\u8c61\u7684\u65f6\u5019\uff0c\u90fd\u4e60\u60ef\u628atoString\u65b9\u6cd5\"\u8986\u76d6\"<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        Person person = new Person();\n        person.setUsername(\"\u5f20\u4e09\");\n        person.setSex(\"\u7537\");\n        person.setAge(11);\n        \/\/\u8f93\u51fa\n        System.out.println(person.toString());\n    }\n}\n\nclass Person{\n    private String username;\n    private String sex;\n    private int age;\n\n    public String getUsername() {\n        return username;\n    }\n\n    public void setUsername(String username) {\n        this.username = username;\n    }\n\n    public String getSex() {\n        return sex;\n    }\n\n    public void setSex(String sex) {\n        this.sex = sex;\n    }\n\n    public int getAge() {\n        return age;\n    }\n\n    public void setAge(int age) {\n        this.age = age;\n    }\n\n    @Override\n    public String toString() {\n        return \"Person{\" +\n                \"username='\" + username + '\\'' +\n                \", sex='\" + sex + '\\'' +\n                \", age=\" + age +\n                '}';\n    }\n}<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" width=\"860\" height=\"360\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-32.png\" alt=\"\" class=\"wp-image-776\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-32.png 860w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-32-300x126.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-32-768x321.png 768w\" sizes=\"(max-width: 860px) 100vw, 860px\" \/><\/figure>\n\n\n\n<h3>6.1.3 finalize\u65b9\u6cd5<\/h3>\n\n\n\n<ul><li>\u5783\u573e\u56de\u6536\u5668(Garbage Collection) GC<ul><li>\u5f53\u5bf9\u8c61\u4e0d\u5728\u4f7f\u7528\u4e86\uff0c\u90a3\u4e48\uff0cGC\u4f1a\u5c06\u5176\u56de\u6536<\/li><li>\u5783\u573e\u56de\u6536\u5728\u540e\u53f0\u8fd0\u884c\uff0c\u6211\u4eec\u6ca1\u6709\u529e\u6cd5\u547d\u4ee4\u7acb\u523b\u56de\u6536\uff0c\u4f46\u662f\uff0c\u53ef\u4ee5\u901a\u77e5<\/li><li>\u5783\u573e\u56de\u6536\u524d\u5fc5\u987b\u8c03\u7528\u7684\u65b9\u6cd5\u5c31\u662ffinalize\uff0c\u5efa\u8bae\u4e0d\u4f7f\u7528\u8fd9\u4e2a\u65b9\u6cd5<\/li><\/ul><\/li><li>\u6848\u4f8b\uff1a<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u521b\u5efa\u5bf9\u8c61\n        Person person = new Person();\n        \/\/\u4e0d\u4f7f\u7528\u4e86\n        person = null;\n        \/\/\u901a\u77e5\u5783\u573e\u56de\u6536\u5668\n        System.gc();\n    }\n}\n\nclass Person{\n    @Override\n    protected void finalize() throws Throwable {\n        System.out.println(\"\u5783\u573e\u56de\u6536\u524d\u8c03\u7528\u4e86\");\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u6269\u5c55<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u521b\u5efa\u5bf9\u8c61\n        Person person = new Person();\n        \/\/\u4f7f\u7528\u5bf9\u8c61\u540e\n        person = null;\n        \n    }\n}\n\n\u5728\u4f7f\u7528\u5b8c\u540e\u662f\u5426\u9700\u8981\u628a\u5bf9\u8c61\u8bbe\u7f6e\u4e3anull\uff1f\n    \u7b54\uff1a\u4e0d\u9700\u8981\u8bbe\u7f6e\u4e3anull\uff0c\u56e0\u4e3a\uff0c\u5728\u65b9\u6cd5\u4e2d\u7684\u53c2\u6570\u90fd\u662f\u5728\u538b\u6808\u65f6\u5b58\u5728\uff0c\u5f39\u6808\u65f6\u4e0d\u5b58\u5728\uff1b<\/code><\/pre>\n\n\n\n<h3>6.1.4 ==\u4e0eequals\u65b9\u6cd5<\/h3>\n\n\n\n<h4>6.1.4.1 \u7b49\u53f7\u201c==\u201d<\/h4>\n\n\n\n<ul><li>\u57fa\u672c\u7c7b\u578b\uff1a\u6bd4\u8f83\u7684\u662f\"\u503c\"<\/li><li>\u5f15\u7528\u7c7b\u578b\uff1a\u6bd4\u8f83\u7684\u662f\"\u5740\"(\u5185\u5b58\u5730\u5740)<\/li><\/ul>\n\n\n\n<p>\u6848\u4f8b1\uff1a\u57fa\u672c\u7c7b\u578b<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo extends Object{\n    public static void main(String&#91;] args) {\n        \/\/\u521b\u5efa\u5bf9\u8c61\n        Person person = new Person();\n        \/\/\u4f7f\u7528\u5bf9\u8c61\u540e\n        person = null;\n        \n    }\n}<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-33.png\" alt=\"\" class=\"wp-image-777\" width=\"842\" height=\"566\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-33.png 717w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-33-300x202.png 300w\" sizes=\"(max-width: 842px) 100vw, 842px\" \/><\/figure>\n\n\n\n<p>\u6848\u4f8b2\uff1a\u5f15\u7528\u7c7b\u578b<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u521b\u5efa\u5bf9\u8c61\n        Person person = new Person();\n        person.setId(1001);\n        person.setUsername(\"\u5f20\u4e09\");\n        \/\/\u521b\u5efa\u5bf9\u8c61\n        Person person1 = new Person();\n        person1.setId(1001);\n        person1.setUsername(\"\u5f20\u4e09\");\n\n        \/\/\u6bd4\u8f83\n        System.out.println(\"person=\"+person);\n        System.out.println(\"person1=\"+person1);\n        System.out.println(person==person1);\n    }\n}\n\nclass Person{\n    private int id;\n    private String username;\n\n    public int getId() {\n        return id;\n    }\n\n    public void setId(int id) {\n        this.id = id;\n    }\n\n    public String getUsername() {\n        return username;\n    }\n\n    public void setUsername(String username) {\n        this.username = username;\n    }\n}<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-34.png\" alt=\"\" class=\"wp-image-778\" width=\"839\" height=\"643\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-34.png 755w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-34-300x230.png 300w\" sizes=\"(max-width: 839px) 100vw, 839px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-35.png\" alt=\"\" class=\"wp-image-779\" width=\"840\" height=\"405\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-35.png 956w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-35-300x145.png 300w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-35-768x371.png 768w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><\/figure>\n\n\n\n<p>\u6848\u4f8b3\uff1a\u5f15\u7528\u7c7b\u578b--\u8fdb\u4e00\u6b65\u5b8c\u5584<\/p>\n\n\n\n<ul><li>equals\u65b9\u6cd5\u9ed8\u8ba4\u4f7f\u7528\u7684\u662f\"==\"<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code><strong>jdk\u7684\u6e90\u4ee3\u7801<\/strong>\npublic boolean equals(Object obj) {\n    return (this == obj);\n}<\/code><\/pre>\n\n\n\n<ul><li>\u9700\u8981\u628a\u5f15\u7528\u7c7b\u578b\u4e2d\u7684\u503c\u6bd4\u8f83\u4e00\u4e0b\uff1aid\u548cusername\u7684\"\u503c\"\u76f8\u540c\uff0c\u90a3\u4e48\uff0c\u5c31\u8ba4\u4e3a\u540c\u4e00\u4e2a\u4eba<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" src=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-36.png\" alt=\"\" class=\"wp-image-780\" width=\"839\" height=\"542\" srcset=\"https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-36.png 754w, https:\/\/axinyi.xuenixiang.com\/wp-content\/uploads\/2022\/03\/\u56fe\u7247-36-300x194.png 300w\" sizes=\"(max-width: 839px) 100vw, 839px\" \/><\/figure>\n\n\n\n<ul><li>String\u7684\u6e90\u4ee3\u7801<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public boolean equals(Object anObject) {\n    if (this == anObject) {\n        return true;\n    }\n    if (anObject instanceof String) {\n        String anotherString = (String)anObject;\n        int n = value.length;\n        if (n == anotherString.value.length) {\n            char v1&#91;] = value;\n            char v2&#91;] = anotherString.value;\n            int i = 0;\n            while (n-- != 0) {\n                if (v1&#91;i] != v2&#91;i])\n                    return false;\n                i++;\n            }\n            return true;\n        }\n    }\n    return false;\n}<\/code><\/pre>\n\n\n\n<ul><li>\u8986\u76d6Object\u4e2d\u7684equals\u65b9\u6cd5<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u521b\u5efa\u5bf9\u8c61\n        Person person = new Person();\n        person.setId(1001);\n        person.setUsername(\"\u5f20\u4e09\");\n        \/\/\u521b\u5efa\u5bf9\u8c61\n        Person person1 = new Person();\n        person1.setId(1001);\n        person1.setUsername(\"\u5f20\u4e09\");\n\n        \/\/\u6bd4\u8f83\n        System.out.println(person==person1);\n        System.out.println(person.equals(person1));\n    }\n}\n\nclass Person{\n    private int id;\n    private String username;\n\n    public int getId() {\n        return id;\n    }\n\n    public void setId(int id) {\n        this.id = id;\n    }\n\n    public String getUsername() {\n        return username;\n    }\n\n    public void setUsername(String username) {\n        this.username = username;\n    }\n\n    @Override\n    public boolean equals(Object anObject) {\n        \/\/\u5982\u679c\u4e24\u4e2a\u5bf9\u8c61\u7684\u5730\u5740\u76f8\u540c\u5c31\u662ftrue\n        if (this == anObject) {\n            return true;\n        }\n        \/\/\u5224\u65ad\u662f\u5426\u4e3a\u6307\u5b9a\u7684\u7c7b\u578b\n        if (anObject instanceof Person) {\n            Person another = (Person)anObject;\n            \/\/\u5224\u65adid\u548cusername\n            if (id==another.getId() &amp;&amp; username.equals(((Person) anObject).getUsername())){\n                return true;\n            }\n        }\n        return false;\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>instanceof\u5224\u65ad\u7c7b\u578b\u4f7f\u7528\u7684<\/li><li>\u6ce8\u610f\uff1a\u5f3a\u5236\u7c7b\u578b\u8f6c\u6362<ul><li>\u5c06\u7236\u7c7b\u8f6c\u4e3a\u5b50\u7c7b\"\u5411\u4e0b\u8f6c\u578b\"\uff0c\u662f\u4e0d\u5b89\u5168\u7684<\/li><li>\u5c06\u5b50\u7c7b\u8f6c\u4e3a\u7236\u7c7b\"\u5411\u4e0a\u8f6c\u578b\"\uff0c\u662f\u5b89\u5168\u7684<\/li><\/ul><\/li><\/ul>\n\n\n\n<h2>6.2 \u8bbf\u95ee\u6743\u9650<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>\u4fee\u9970\u7b26<\/th><th>\u7c7b\u7684\u5185\u90e8<\/th><th>\u540c\u4e00\u4e2a\u5305<\/th><th>\u5b50\u7c7b(\u4e0d\u540c\u5305)<\/th><th>\u4efb\u4f55\u4f4d\u7f6e<\/th><\/tr><\/thead><tbody><tr><td>public<\/td><td>Y<\/td><td>Y<\/td><td>Y<\/td><td>Y<\/td><\/tr><tr><td>private<\/td><td>Y<\/td><td>N<\/td><td>N<\/td><td>N<\/td><\/tr><tr><td>protected<\/td><td>Y<\/td><td>Y<\/td><td>Y<\/td><td>N<\/td><\/tr><tr><td>default<\/td><td>Y<\/td><td>Y<\/td><td>N<\/td><td>N<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2>6.3 \u5185\u90e8\u7c7b<\/h2>\n\n\n\n<h3>6.3.1 \u5206\u7c7b<\/h3>\n\n\n\n<ul><li>\u5b9e\u4f8b\u5185\u90e8\u7c7b\uff1a\u5fc5\u987b\u6301\u6709\u5916\u90e8\u7684\u5f15\u7528(\u5b9e\u4f8b)<\/li><li>\u9759\u6001\u5185\u90e8\u7c7b\uff1a\u4e0d\u9700\u8981\u6301\u6709\u5916\u90e8\u7684\u5f15\u7528(\u5b9e\u4f8b)<\/li><li>\u5c40\u90e8\u5185\u90e8\u7c7b\uff1a\u5728\u65b9\u6cd5\u4e2d\u4f7f\u7528<\/li><\/ul>\n\n\n\n<h3>6.3.2 \u5b9e\u4f8b\u5185\u90e8\u7c7b<\/h3>\n\n\n\n<ul><li>\u5fc5\u987b\u6301\u6709\u5916\u90e8\u7684\u5f15\u7528(\u5b9e\u4f8b)\uff1a\u5c31\u662f\u5185\u5916\u4e24\u4e2a\u5bf9\u8c61\u90fd\u521b\u5efa<\/li><li>\u5185\u90e8\u4e0d\u80fd\u5b9a\u4e49static\u6210\u5458\uff0c\u53ea\u80fd\u662f\u5b9e\u4f8b\u6210\u5458<\/li><li>\u6848\u4f8b\uff1a\u7b2c\u4e00\u79cd\u65b9\u5f0f<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u4f7f\u7528\u5185\u90e8\u7c7b\n        A a = new A();\n        a.show();   \/\/\u8c03\u7528\u81ea\u5df1\u7684\u6210\u5458\u65b9\u6cd5\n\n        \/\/\u518d\u521b\u5efa\u5185\u90e8\u7684\u5bf9\u8c61\n        A.B b = a.new B();\n        b.save();\n    }\n}\n\nclass A{\n    \/\/\u6210\u5458\u65b9\u6cd5\n    public void show(){\n        System.out.println(\"A--method\");\n    }\n\n    class B{\/\/\u5185\u90e8\u7c7b\n        public void save(){\n            System.out.println(\"B--method\");\n            \/\/\u53ef\u4ee5\u8c03\u7528\u5916\u90e8\u7684\u6210\u5458\u65b9\u6cd5\n            show();\n        }\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u7b2c\u4e8c\u79cd\u65b9\u5f0f<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u76f4\u63a5\u521b\u5efa\u5bf9\u8c61\n        A.B b = new A().new B();\n        b.save();\n    }\n}\n\nclass A{\n    \/\/\u6210\u5458\u65b9\u6cd5\n    public void show(){\n        System.out.println(\"A--method\");\n    }\n\n    class B{\/\/\u5185\u90e8\u7c7b\n        public void save(){\n            System.out.println(\"B--method\");\n            \/\/\u53ef\u4ee5\u8c03\u7528\u5916\u90e8\u7684\u6210\u5458\u65b9\u6cd5\n            show();\n        }\n    }\n}<\/code><\/pre>\n\n\n\n<h3>6.3.3 \u9759\u6001\u5185\u90e8\u7c7b<\/h3>\n\n\n\n<ul><li>\u4e0d\u9700\u8981\u6301\u6709\u5916\u90e8\u7684\u5f15\u7528<\/li><li>\u9759\u6001\u5185\u90e8\u7c7b\u53ef\u4ee5\u8bbf\u95ee\u5916\u90e8\u7684\u9759\u6001\u53d8\u91cf\uff0c\u5982\u679c\u9700\u8981\u8bbf\u95ee\u5916\u90e8\u7684\u6210\u5458\u53d8\u91cf\u5fc5\u987b\u901a\u8fc7\u5916\u90e8\u7684\u5bf9\u8c61\u65b9\u6cd5<\/li><li>\u6848\u4f8b\uff1a<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u4e0d\u9700\u8981\u5916\u90e8\u521b\u5efa\u5bf9\u8c61\uff0c\u76f4\u63a5\u521b\u5efa\u5185\u90e8\u5bf9\u8c61\u5373\u53ef\n        A.B b = new A.B();\n        b.save();\n        \/\/\u53ef\u4ee5\u76f4\u63a5\u8c03\u7528\u9759\u6001\u65b9\u6cd5\n        System.out.println(A.B.i);\n    }\n}\n\nclass A{\n\n    \/\/\u9759\u6001\u65b9\u6cd5\n    public static void show(){\n        System.out.println(\"A--method\");\n    }\n\n    static class B{\/\/\u5185\u90e8\u7c7b\n        public static int i =100;\n        public void save(){\n            System.out.println(\"B--method\");\n            \/\/\u53ef\u4ee5\u8c03\u7528\u5916\u90e8\u7684\u6210\u5458\u65b9\u6cd5\n            show();\n        }\n    }\n}<\/code><\/pre>\n\n\n\n<h3>6.3.4 \u5c40\u90e8\u5185\u90e8\u7c7b<\/h3>\n\n\n\n<ul><li>\u5c31\u662f\u5728\u65b9\u6cd5\u4e2d\u521b\u5efa\u7684\u7c7b\uff1b\u548c\u5c40\u90e8\u53d8\u91cf\u7684\u4f7f\u7528\u662f\u76f8\u540c\u7684<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        \/\/\u521b\u5efa\u5bf9\u8c61\uff0c\u8c03\u7528\u6210\u5458\u65b9\u6cd5\n        new A().method(100);\n    }\n}\n\nclass A{\n    \n    public void method(int i){\n        \/\/\u76f8\u5f53\u4e8e\u81ea\u5b9a\u4e49\u4e86\u4e00\u79cd\u53ea\u5728\u65b9\u6cd5\u5185\u4f7f\u7528\u7684\u7c7b\u578b\n        class B{\n            public void save(){\n                System.out.println(\"----->>\"+i);\n            }\n        }\n        \/\/\u5728\u65b9\u6cd5\u5185\u4f7f\u7528\n        B b = new B();\n        b.save();\n    }\n}<\/code><\/pre>\n\n\n\n<h3>6.3.5 \u6269\u5c55\uff1a\u533f\u540d\u5185\u90e8\u7c7b<\/h3>\n\n\n\n<ul><li>\u63a5\u53e3\u4f5c\u4e3a\u65b9\u6cd5\u7684\u533f\u540d\u4f7f\u7528<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        B b = new B();\n        \/\/\u8c03\u7528\u65b9\u6cd5\uff0c\u533f\u540d\u5b9e\u73b0\u63a5\u53e3\u4e2d\u7684\u65b9\u6cd5\n        Object exec = b.exec(new A() {\n            @Override\n            public Object callBack() {\n                return \"\u533f\u540d\u5b9e\u73b0\";\n            }\n        });\n\n        System.out.println(exec);\n    }\n}\n\ninterface A{\n    Object callBack();\n}\n\nclass B{\n    \/\/\u6210\u5458\u65b9\u6cd5\n    public Object exec(A a){\n        return a.callBack();\n    }\n}<\/code><\/pre>\n\n\n\n<ul><li>\u4f7f\u7528lambda\u51fd\u6570<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public class Demo {\n    public static void main(String&#91;] args) {\n        A a = ()->\"lambda\u51fd\u6570\u65b9\u5f0f\u5b9e\u73b0\";\n        \/\/\u8c03\u7528\n        Object back = a.callBack();\n        System.out.println(back);\n    }\n}\n\ninterface A{\n        Object callBack();\n}<\/code><\/pre>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u7b2c\u56db\u7ae0 \u9762\u5411\u5bf9\u8c61 4.1 \u65b9\u6cd5 \u65b9\u6cd5\uff1a\u5c31\u662f\u4e00\u79cd\u529f\u80fd\u7684\u4f53\u73b0\u3002\u65b9\u6cd5\u662f\u53ef\u4ee5\u590d\u7528\u7684 \u683c\u5f0f\uff1a \u65b9\u6cd5\u7684\u4fee\u9970\u7b26 \u8fd4\u56de\u7c7b\u578b \u65b9\u6cd5\u540d\u79f0(\u53c2\u6570){ \u65b9 &#8230;<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[10],"tags":[],"_links":{"self":[{"href":"https:\/\/axinyi.xuenixiang.com\/index.php\/wp-json\/wp\/v2\/posts\/673"}],"collection":[{"href":"https:\/\/axinyi.xuenixiang.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/axinyi.xuenixiang.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/axinyi.xuenixiang.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/axinyi.xuenixiang.com\/index.php\/wp-json\/wp\/v2\/comments?post=673"}],"version-history":[{"count":9,"href":"https:\/\/axinyi.xuenixiang.com\/index.php\/wp-json\/wp\/v2\/posts\/673\/revisions"}],"predecessor-version":[{"id":781,"href":"https:\/\/axinyi.xuenixiang.com\/index.php\/wp-json\/wp\/v2\/posts\/673\/revisions\/781"}],"wp:attachment":[{"href":"https:\/\/axinyi.xuenixiang.com\/index.php\/wp-json\/wp\/v2\/media?parent=673"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/axinyi.xuenixiang.com\/index.php\/wp-json\/wp\/v2\/categories?post=673"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/axinyi.xuenixiang.com\/index.php\/wp-json\/wp\/v2\/tags?post=673"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}