{"id":1398,"date":"2025-08-21T16:30:36","date_gmt":"2025-08-21T08:30:36","guid":{"rendered":"https:\/\/zero-zl.cn\/?p=1398"},"modified":"2025-08-21T22:20:32","modified_gmt":"2025-08-21T14:20:32","slug":"java%e6%9e%9a%e4%b8%be-%e6%b3%9b%e5%9e%8b","status":"publish","type":"post","link":"https:\/\/zero-zl.cn\/index.php\/2025\/08\/21\/java%e6%9e%9a%e4%b8%be-%e6%b3%9b%e5%9e%8b\/","title":{"rendered":"Java\u679a\u4e3e &amp; \u6cdb\u578b"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\" id=\"_1\u3001\u4ec0\u4e48\u662f\u679a\u4e3e\u7c7b\"><a href=\"#_1\u3001\u4ec0\u4e48\u662f\u679a\u4e3e\u7c7b\">1\u3001\u4ec0\u4e48\u662f\u679a\u4e3e\u7c7b\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u679a\u4e3e\u7c7b\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u7c7b\uff0c\u5b83\u7528\u4e8e\u5b9a\u4e49\u4e00\u7ec4\u56fa\u5b9a\u7684\u5e38\u91cf\u3002\u679a\u4e3e\u7c7b\u4e2d\u7684\u6bcf\u4e2a\u5e38\u91cf\u90fd\u662f\u8be5\u7c7b\u7684\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u5e76\u4e14\u5e38\u91cf\u4e4b\u95f4\u662f\u552f\u4e00\u7684\uff0c\u4e0d\u80fd\u91cd\u590d\u3002\u679a\u4e3e\u7c7b\u53ef\u4ee5\u7528\u4e8e\u8868\u793a\u4e00\u7ec4\u76f8\u5173\u7684\u5e38\u91cf\uff0c\u4f8b\u5982\u8868\u793a\u661f\u671f\u51e0\u3001\u6708\u4efd\u3001\u989c\u8272\u7b49\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee5\u4e0b\u662f\u4e00\u4e2aJava\u8bed\u8a00\u4e2d\u679a\u4e3e\u7c7b\u7684\u793a\u4f8b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>enum Day {\n    MONDAY,\n    TUESDAY,\n    WEDNESDAY,\n    THURSDAY,\n    FRIDAY,\n    SATURDAY,\n    SUNDAY\n}\n\n\/\/ \u4f7f\u7528\u679a\u4e3e\u7c7b\nDay today = Day.MONDAY;\nif (today == Day.MONDAY) {\n    System.out.println(\"\u4eca\u5929\u662f\u661f\u671f\u4e00\");\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c<code>Day<\/code>\u662f\u4e00\u4e2a\u679a\u4e3e\u7c7b\uff0c\u5b83\u5b9a\u4e49\u4e86\u4e00\u5468\u4e2d\u7684\u6bcf\u4e00\u5929\u4f5c\u4e3a\u5e38\u91cf\u3002\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u679a\u4e3e\u7c7b\u6765\u8868\u793a\u4eca\u5929\u662f\u661f\u671f\u51e0\uff0c\u5e76\u8fdb\u884c\u6bd4\u8f83\u548c\u5176\u4ed6\u64cd\u4f5c\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_2\u3001\u679a\u4e3e\u7c7b\u7684\u5e38\u91cf\u53ef\u4ee5\u6709\u81ea\u5df1\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\u5417\"><a href=\"#_2\u3001\u679a\u4e3e\u7c7b\u7684\u5e38\u91cf\u53ef\u4ee5\u6709\u81ea\u5df1\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\u5417\">2\u3001\u679a\u4e3e\u7c7b\u7684\u5e38\u91cf\u53ef\u4ee5\u6709\u81ea\u5df1\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\u5417\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u662f\u7684\uff0c\u679a\u4e3e\u7c7b\u7684\u5e38\u91cf\u53ef\u4ee5\u5177\u6709\u81ea\u5df1\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\u3002\u6bcf\u4e2a\u679a\u4e3e\u5e38\u91cf\u90fd\u662f\u679a\u4e3e\u7c7b\u7684\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u56e0\u6b64\u53ef\u4ee5\u50cf\u666e\u901a\u7c7b\u4e00\u6837\u4e3a\u5e38\u91cf\u5b9a\u4e49\u5c5e\u6027\u548c\u65b9\u6cd5\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee5\u4e0b\u662f\u4e00\u4e2aJava\u8bed\u8a00\u4e2d\u679a\u4e3e\u7c7b\u5e38\u91cf\u5177\u6709\u5c5e\u6027\u548c\u65b9\u6cd5\u7684\u793a\u4f8b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>enum Day {\n    MONDAY(\"\u661f\u671f\u4e00\", 1),\n    TUESDAY(\"\u661f\u671f\u4e8c\", 2),\n    WEDNESDAY(\"\u661f\u671f\u4e09\", 3),\n    THURSDAY(\"\u661f\u671f\u56db\", 4),\n    FRIDAY(\"\u661f\u671f\u4e94\", 5),\n    SATURDAY(\"\u661f\u671f\u516d\", 6),\n    SUNDAY(\"\u661f\u671f\u65e5\", 7);\n\n    private String name;\n    private int value;\n\n    Day(String name, int value) {\n        this.name = name;\n        this.value = value;\n    }\n\n    public String getName() {\n        return name;\n    }\n\n    public int getValue() {\n        return value;\n    }\n}\n\n\/\/ \u4f7f\u7528\u679a\u4e3e\u7c7b\u5e38\u91cf\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\nDay today = Day.MONDAY;\nSystem.out.println(\"\u4eca\u5929\u662f\uff1a\" + today.getName());\nSystem.out.println(\"\u5bf9\u5e94\u7684\u503c\u662f\uff1a\" + today.getValue());<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c<code>Day<\/code>\u679a\u4e3e\u7c7b\u7684\u6bcf\u4e2a\u5e38\u91cf\u90fd\u6709\u4e00\u4e2a<code>name<\/code>\u5c5e\u6027\u548c\u4e00\u4e2a<code>value<\/code>\u5c5e\u6027\uff0c\u4ee5\u53ca\u76f8\u5e94\u7684\u6784\u9020\u65b9\u6cd5\u548c\u83b7\u53d6\u5c5e\u6027\u503c\u7684\u65b9\u6cd5\u3002\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u679a\u4e3e\u7c7b\u5e38\u91cf\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\u6765\u83b7\u53d6\u76f8\u5173\u4fe1\u606f\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_3\u3001\u679a\u4e3e\u7c7b\u53ef\u4ee5\u5b9e\u73b0\u63a5\u53e3\u5417\"><a href=\"#_3\u3001\u679a\u4e3e\u7c7b\u53ef\u4ee5\u5b9e\u73b0\u63a5\u53e3\u5417\">3\u3001\u679a\u4e3e\u7c7b\u53ef\u4ee5\u5b9e\u73b0\u63a5\u53e3\u5417\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u662f\u7684\uff0c\u679a\u4e3e\u7c7b\u53ef\u4ee5\u5b9e\u73b0\u63a5\u53e3\u3002\u5728Java\u4e2d\uff0c\u679a\u4e3e\u7c7b\u4e5f\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u7c7b\uff0c\u53ef\u4ee5\u5b9e\u73b0\u63a5\u53e3\u5e76\u91cd\u5199\u63a5\u53e3\u4e2d\u7684\u65b9\u6cd5\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8981\u8ba9\u679a\u4e3e\u7c7b\u5b9e\u73b0\u63a5\u53e3\uff0c\u53ea\u9700\u5728\u679a\u4e3e\u7c7b\u7684\u5b9a\u4e49\u4e2d\u4f7f\u7528\u5173\u952e\u5b57 &#8220;implements&#8221; \u540e\u8ddf\u4e0a\u8981\u5b9e\u73b0\u7684\u63a5\u53e3\u540d\u79f0\u3002\u7136\u540e\uff0c\u9700\u8981\u5728\u679a\u4e3e\u7c7b\u4e2d\u5b9e\u73b0\u63a5\u53e3\u4e2d\u5b9a\u4e49\u7684\u6240\u6709\u65b9\u6cd5\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0b\u9762\u662f\u4e00\u4e2a\u793a\u4f8b\uff0c\u5c55\u793a\u4e86\u4e00\u4e2a\u679a\u4e3e\u7c7b\u5b9e\u73b0\u63a5\u53e3\u7684\u4f8b\u5b50\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>enum Color implements Printable {\n    RED(\"\u7ea2\u8272\"), GREEN(\"\u7eff\u8272\"), BLUE(\"\u84dd\u8272\");\n\n    private String name;\n\n    Color(String name) {\n        this.name = name;\n    }\n\n    public String getName() {\n        return name;\n    }\n\n    \/\/ \u5b9e\u73b0\u63a5\u53e3\u4e2d\u7684\u65b9\u6cd5\n    @Override\n    public void print() {\n        System.out.println(\"\u989c\u8272\uff1a\" + name);\n    }\n}\n\n\/\/ \u5b9a\u4e49\u4e00\u4e2a\u63a5\u53e3\ninterface Printable {\n    void print();\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u679a\u4e3e\u7c7b <code>Color<\/code> \u5b9e\u73b0\u4e86\u63a5\u53e3 <code>Printable<\/code>\uff0c\u5e76\u91cd\u5199\u4e86\u63a5\u53e3\u4e2d\u7684 <code>print()<\/code> \u65b9\u6cd5\u3002\u679a\u4e3e\u7c7b\u4e2d\u7684\u6bcf\u4e2a\u5e38\u91cf\u90fd\u662f\u8be5\u679a\u4e3e\u7c7b\u7684\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u53ef\u4ee5\u8c03\u7528\u63a5\u53e3\u4e2d\u7684\u65b9\u6cd5\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u679a\u4e3e\u7c7b\u5b9e\u73b0\u63a5\u53e3\u53ef\u4ee5\u4e3a\u679a\u4e3e\u5e38\u91cf\u63d0\u4f9b\u66f4\u591a\u7684\u884c\u4e3a\u548c\u529f\u80fd\uff0c\u5e76\u4e14\u53ef\u4ee5\u5728\u4ee3\u7801\u4e2d\u4f7f\u7528\u63a5\u53e3\u7c7b\u578b\u6765\u5f15\u7528\u679a\u4e3e\u5e38\u91cf\uff0c\u4ece\u800c\u589e\u52a0\u4ee3\u7801\u7684\u7075\u6d3b\u6027\u548c\u53ef\u6269\u5c55\u6027\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_4\u3001\u5982\u4f55\u904d\u5386\u679a\u4e3e\u7c7b\u4e2d\u7684\u5e38\u91cf\"><a href=\"#_4\u3001\u5982\u4f55\u904d\u5386\u679a\u4e3e\u7c7b\u4e2d\u7684\u5e38\u91cf\">4\u3001\u5982\u4f55\u904d\u5386\u679a\u4e3e\u7c7b\u4e2d\u7684\u5e38\u91cf\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u4f7f\u7528\u679a\u4e3e\u7c7b\u7684values()\u65b9\u6cd5\u83b7\u53d6\u679a\u4e3e\u7c7b\u7684\u6240\u6709\u5e38\u91cf\uff0c\u5e76\u8fdb\u884c\u904d\u5386\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_5\u3001\u679a\u4e3e\u7c7b\u4e0e\u666e\u901a\u7c7b\u7684\u533a\u522b\u662f\u4ec0\u4e48\"><a href=\"#_5\u3001\u679a\u4e3e\u7c7b\u4e0e\u666e\u901a\u7c7b\u7684\u533a\u522b\u662f\u4ec0\u4e48\">5\u3001\u679a\u4e3e\u7c7b\u4e0e\u666e\u901a\u7c7b\u7684\u533a\u522b\u662f\u4ec0\u4e48\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u679a\u4e3e\u7c7b\u53ef\u4ee5\u786e\u4fdd\u5e38\u91cf\u7684\u552f\u4e00\u6027\u4e14\u7c7b\u578b\u5b89\u5168\uff0c\u53ef\u4ee5\u76f4\u63a5\u6bd4\u8f83\u548c\u4f7f\u7528\uff0c\u800c\u666e\u901a\u7c7b\u5219\u9700\u8981\u901a\u8fc7\u5bf9\u8c61\u6765\u6bd4\u8f83\u548c\u4f7f\u7528<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_6\u3001\u679a\u4e3e\u7c7b\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\u7684\u5e94\u7528\u573a\u666f\u6709\u54ea\u4e9b\"><a href=\"#_6\u3001\u679a\u4e3e\u7c7b\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\u7684\u5e94\u7528\u573a\u666f\u6709\u54ea\u4e9b\">6\u3001\u679a\u4e3e\u7c7b\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\u7684\u5e94\u7528\u573a\u666f\u6709\u54ea\u4e9b\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u679a\u4e3e\u7c7b\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\u5e38\u7528\u4e8e\u5b9a\u4e49\u4e00\u7ec4\u76f8\u5173\u5e38\u91cf\u3001\u72b6\u6001\u673a\u3001\u5355\u4f8b\u6a21\u5f0f\u7b49\u573a\u666f<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_7\u3001\u5982\u4f55\u6bd4\u8f83\u4e24\u4e2a\u679a\u4e3e\u5e38\u91cf\u7684\u987a\u5e8f\"><a href=\"#_7\u3001\u5982\u4f55\u6bd4\u8f83\u4e24\u4e2a\u679a\u4e3e\u5e38\u91cf\u7684\u987a\u5e8f\">7\u3001\u5982\u4f55\u6bd4\u8f83\u4e24\u4e2a\u679a\u4e3e\u5e38\u91cf\u7684\u987a\u5e8f\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u4f7f\u7528\u679a\u4e3e\u5e38\u91cf\u7684compareTo()\u65b9\u6cd5\u6765\u6bd4\u8f83\u4e24\u4e2a\u679a\u4e3e\u5e38\u91cf\u7684\u987a\u5e8f\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_8\u3001\u679a\u4e3e\u7c7b\u53ef\u4ee5\u7ee7\u627f\u5176\u4ed6\u7c7b\u5417\"><a href=\"#_8\u3001\u679a\u4e3e\u7c7b\u53ef\u4ee5\u7ee7\u627f\u5176\u4ed6\u7c7b\u5417\">8\u3001\u679a\u4e3e\u7c7b\u53ef\u4ee5\u7ee7\u627f\u5176\u4ed6\u7c7b\u5417\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">Java\u4e2d\u7684\u679a\u4e3e\u7c7b\u9ed8\u8ba4\u7ee7\u627f\u81eajava.lang.Enum\u7c7b\uff0c\u4e0d\u652f\u6301\u7ee7\u627f\u5176\u4ed6\u7c7b\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_9\u3001\u5982\u4f55\u6269\u5c55\u679a\u4e3e\u7c7b\u7684\u529f\u80fd\"><a href=\"#_9\u3001\u5982\u4f55\u6269\u5c55\u679a\u4e3e\u7c7b\u7684\u529f\u80fd\">9\u3001\u5982\u4f55\u6269\u5c55\u679a\u4e3e\u7c7b\u7684\u529f\u80fd\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u53ef\u4ee5\u4f7f\u7528\u62bd\u8c61\u65b9\u6cd5\uff0c\u5728\u679a\u4e3e\u7c7b\u7684\u6bcf\u4e2a\u5e38\u91cf\u4e2d\u5b9e\u73b0\u8be5\u62bd\u8c61\u65b9\u6cd5\uff0c\u4ee5\u4fbf\u4e3a\u6bcf\u4e2a\u5e38\u91cf\u5b9a\u5236\u4e0d\u540c\u7684\u884c\u4e3a<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_10\u3001\u4ec0\u4e48\u662f\u6cdb\u578b\"><a href=\"#_10\u3001\u4ec0\u4e48\u662f\u6cdb\u578b\">10\u3001\u4ec0\u4e48\u662f\u6cdb\u578b\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u6cdb\u578b\uff08Generics\uff09\u662fJava\u4e2d\u7684\u4e00\u4e2a\u91cd\u8981\u7279\u6027\uff0c\u5b83\u63d0\u4f9b\u4e86\u5728\u7f16\u8bd1\u65f6\u671f\u5bf9\u7c7b\u578b\u8fdb\u884c\u53c2\u6570\u5316\u7684\u80fd\u529b\u3002\u901a\u8fc7\u4f7f\u7528\u6cdb\u578b\uff0c\u53ef\u4ee5\u5728\u7f16\u5199\u7c7b\u3001\u63a5\u53e3\u548c\u65b9\u6cd5\u65f6\u6307\u5b9a\u7c7b\u578b\u53c2\u6570\uff0c\u4ece\u800c\u589e\u52a0\u4ee3\u7801\u7684\u7075\u6d3b\u6027\u548c\u5b89\u5168\u6027\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6cdb\u578b\u7684\u4e3b\u8981\u76ee\u7684\u662f\u5b9e\u73b0\u7c7b\u578b\u7684\u53c2\u6570\u5316\uff0c\u4f7f\u5f97\u4ee3\u7801\u80fd\u591f\u9002\u7528\u4e8e\u591a\u79cd\u4e0d\u540c\u7c7b\u578b\u7684\u6570\u636e\uff0c\u800c\u4e0d\u9700\u8981\u4e3a\u6bcf\u79cd\u7c7b\u578b\u90fd\u7f16\u5199\u72ec\u7acb\u7684\u4ee3\u7801\u3002\u4f7f\u7528\u6cdb\u578b\u53ef\u4ee5\u907f\u514d\u7c7b\u578b\u8f6c\u6362\u9519\u8bef\u548c\u8fd0\u884c\u65f6\u5f02\u5e38\uff0c\u5e76\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u548c\u91cd\u7528\u6027\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4f7f\u7528\u6cdb\u578b\u65f6\uff0c\u9700\u8981\u4f7f\u7528\u5c16\u62ec\u53f7\uff08&lt;&gt;\uff09\u6765\u6307\u5b9a\u7c7b\u578b\u53c2\u6570\u3002\u5e38\u89c1\u7684\u6cdb\u578b\u7c7b\u578b\u53c2\u6570\u547d\u540d\u7ea6\u5b9a\u6709\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>E\uff1a\u8868\u793a\u5143\u7d20\uff08Element\uff09\uff0c\u5e38\u7528\u4e8e\u96c6\u5408\u7c7b\u4e2d<\/li>\n\n\n\n<li>T\uff1a\u8868\u793a\u7c7b\u578b\uff08Type\uff09<\/li>\n\n\n\n<li>K\uff1a\u8868\u793a\u952e\uff08Key\uff09<\/li>\n\n\n\n<li>V\uff1a\u8868\u793a\u503c\uff08Value\uff09<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0b\u9762\u662f\u4e00\u4e2a\u4f7f\u7528\u6cdb\u578b\u7684\u793a\u4f8b\uff0c\u5c55\u793a\u4e86\u4e00\u4e2a\u6cdb\u578b\u7c7b\u7684\u5b9a\u4e49\u548c\u4f7f\u7528\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Box&lt;T&gt; {\n    private T value;\n\n    public void setValue(T value) {\n        this.value = value;\n    }\n\n    public T getValue() {\n        return value;\n    }\n}\n\n\/\/ \u4f7f\u7528\u6cdb\u578b\u7c7b\nBox&lt;Integer&gt; box = new Box&lt;&gt;();\nbox.setValue(10);\nint value = box.getValue(); \/\/ \u4e0d\u9700\u8981\u8fdb\u884c\u7c7b\u578b\u8f6c\u6362\uff0c\u76f4\u63a5\u83b7\u53d6\u5230 Integer \u7c7b\u578b\u7684\u503c<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c<code>Box<\/code> \u7c7b\u662f\u4e00\u4e2a\u6cdb\u578b\u7c7b\uff0c\u901a\u8fc7\u4f7f\u7528\u7c7b\u578b\u53c2\u6570 <code>T<\/code>\uff0c\u53ef\u4ee5\u5728\u5b9e\u4f8b\u5316 <code>Box<\/code> \u5bf9\u8c61\u65f6\u6307\u5b9a\u5177\u4f53\u7684\u7c7b\u578b\u3002\u5728\u4f7f\u7528 <code>Box<\/code> \u5bf9\u8c61\u65f6\uff0c\u4e0d\u9700\u8981\u8fdb\u884c\u7c7b\u578b\u8f6c\u6362\uff0c\u53ef\u4ee5\u76f4\u63a5\u83b7\u53d6\u5230\u6307\u5b9a\u7c7b\u578b\u7684\u503c\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u9664\u4e86\u6cdb\u578b\u7c7b\uff0c\u8fd8\u6709\u6cdb\u578b\u63a5\u53e3\u548c\u6cdb\u578b\u65b9\u6cd5\u3002\u6cdb\u578b\u63a5\u53e3\u548c\u6cdb\u578b\u65b9\u6cd5\u7684\u4f7f\u7528\u65b9\u5f0f\u7c7b\u4f3c\uff0c\u90fd\u662f\u5728\u5b9a\u4e49\u65f6\u6307\u5b9a\u7c7b\u578b\u53c2\u6570\uff0c\u5e76\u5728\u4f7f\u7528\u65f6\u6307\u5b9a\u5177\u4f53\u7684\u7c7b\u578b\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_11\u3001\u5982\u4f55\u5728\u6cdb\u578b\u4e2d\u4f7f\u7528\u7ee7\u627f\u5173\u7cfb\"><a href=\"#_11\u3001\u5982\u4f55\u5728\u6cdb\u578b\u4e2d\u4f7f\u7528\u7ee7\u627f\u5173\u7cfb\">11\u3001\u5982\u4f55\u5728\u6cdb\u578b\u4e2d\u4f7f\u7528\u7ee7\u627f\u5173\u7cfb\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u5728\u6cdb\u578b\u4e2d\u4f7f\u7528\u7ee7\u627f\u5173\u7cfb\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528\u6cdb\u578b\u7684\u4e0a\u754c\uff08bounded type\uff09\u6765\u5b9e\u73b0\u3002\u6cdb\u578b\u7684\u4e0a\u754c\u6307\u5b9a\u4e86\u6cdb\u578b\u53c2\u6570\u5fc5\u987b\u662f\u6307\u5b9a\u7c7b\u578b\u6216\u5176\u5b50\u7c7b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0b\u9762\u662f\u4e00\u4e2a\u793a\u4f8b\uff0c\u5c55\u793a\u4e86\u5982\u4f55\u5728\u6cdb\u578b\u4e2d\u4f7f\u7528\u7ee7\u627f\u5173\u7cfb\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class Animal {\n    public void eat() {\n        System.out.println(\"Animal is eating.\");\n    }\n}\n\nclass Dog extends Animal {\n    public void bark() {\n        System.out.println(\"Dog is barking.\");\n    }\n}\n\nclass Cat extends Animal {\n    public void meow() {\n        System.out.println(\"Cat is meowing.\");\n    }\n}\n\nclass Box&lt;T extends Animal&gt; {\n    private T animal;\n\n    public void setAnimal(T animal) {\n        this.animal = animal;\n    }\n\n    public T getAnimal() {\n        return animal;\n    }\n}\n\npublic class Main {\n    public static void main(String&#91;] args) {\n        Box&lt;Dog&gt; dogBox = new Box&lt;&gt;();\n        Dog dog = new Dog();\n        dogBox.setAnimal(dog);\n\n        Box&lt;Cat&gt; catBox = new Box&lt;&gt;();\n        Cat cat = new Cat();\n        catBox.setAnimal(cat);\n        \n        Dog dogFromBox = dogBox.getAnimal();\n        dogFromBox.eat();\n        dogFromBox.bark();\n\n        Cat catFromBox = catBox.getAnimal();\n        catFromBox.eat();\n        catFromBox.meow();\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0c<code>Box<\/code> \u7c7b\u4f7f\u7528\u4e86\u6cdb\u578b\u53c2\u6570 <code>T<\/code>\uff0c\u5e76\u901a\u8fc7 <code>T extends Animal<\/code> \u6307\u5b9a\u4e86\u6cdb\u578b\u7684\u4e0a\u754c\u4e3a <code>Animal<\/code> \u7c7b\u578b\u6216\u5176\u5b50\u7c7b\u3002\u8fd9\u6837\uff0c\u6211\u4eec\u53ef\u4ee5\u5728 <code>Box<\/code> \u7c7b\u4e2d\u5b58\u50a8 <code>Animal<\/code> \u7c7b\u578b\u7684\u5bf9\u8c61\u6216\u5176\u5b50\u7c7b\u5bf9\u8c61\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 <code>main<\/code> \u65b9\u6cd5\u4e2d\uff0c\u6211\u4eec\u521b\u5efa\u4e86\u4e00\u4e2a <code>Box&lt;Dog&gt;<\/code> \u5bf9\u8c61\u548c\u4e00\u4e2a <code>Box&lt;Cat&gt;<\/code> \u5bf9\u8c61\uff0c\u5e76\u5c06 <code>Dog<\/code> \u5bf9\u8c61\u548c <code>Cat<\/code> \u5bf9\u8c61\u5206\u522b\u5b58\u50a8\u5230\u8fd9\u4e24\u4e2a <code>Box<\/code> \u5bf9\u8c61\u4e2d\u3002\u7136\u540e\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7 <code>getAnimal<\/code> \u65b9\u6cd5\u83b7\u53d6\u5230\u5b58\u50a8\u5728 <code>Box<\/code> \u5bf9\u8c61\u4e2d\u7684\u52a8\u7269\u5bf9\u8c61\uff0c\u5e76\u8c03\u7528\u5176\u65b9\u6cd5\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u901a\u8fc7\u4f7f\u7528\u6cdb\u578b\u7684\u4e0a\u754c\uff0c\u6211\u4eec\u53ef\u4ee5\u9650\u5236\u6cdb\u578b\u53c2\u6570\u7684\u7c7b\u578b\u8303\u56f4\uff0c\u4ece\u800c\u5728\u6cdb\u578b\u4e2d\u4f7f\u7528\u7ee7\u627f\u5173\u7cfb\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_12\u3001\u6cdb\u578b\u4e2d\u7684\u81ea\u52a8\u88c5\u7bb1\u548c\u62c6\u7bb1\u5982\u4f55\u53d1\u751f\"><a href=\"#_12\u3001\u6cdb\u578b\u4e2d\u7684\u81ea\u52a8\u88c5\u7bb1\u548c\u62c6\u7bb1\u5982\u4f55\u53d1\u751f\">12\u3001\u6cdb\u578b\u4e2d\u7684\u81ea\u52a8\u88c5\u7bb1\u548c\u62c6\u7bb1\u5982\u4f55\u53d1\u751f\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u5728\u6cdb\u578b\u4e2d\uff0c\u81ea\u52a8\u88c5\u7bb1\u548c\u62c6\u7bb1\u662f\u6307\u5c06\u57fa\u672c\u7c7b\u578b\u6570\u636e\u81ea\u52a8\u8f6c\u6362\u4e3a\u5bf9\u5e94\u7684\u5305\u88c5\u7c7b\u578b\uff0c\u4ee5\u53ca\u5c06\u5305\u88c5\u7c7b\u578b\u81ea\u52a8\u8f6c\u6362\u4e3a\u5bf9\u5e94\u7684\u57fa\u672c\u7c7b\u578b\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5f53\u6211\u4eec\u4f7f\u7528\u6cdb\u578b\u65f6\uff0c\u5982\u679c\u6cdb\u578b\u7c7b\u578b\u53c2\u6570\u662f\u5305\u88c5\u7c7b\u578b\uff08\u5982Integer\u3001Double\u7b49\uff09\uff0c\u800c\u6211\u4eec\u53c8\u4f20\u5165\u4e86\u5bf9\u5e94\u7684\u57fa\u672c\u7c7b\u578b\u6570\u636e\uff08\u5982int\u3001double\u7b49\uff09\uff0c\u7f16\u8bd1\u5668\u4f1a\u81ea\u52a8\u8fdb\u884c\u88c5\u7bb1\u64cd\u4f5c\uff0c\u5c06\u57fa\u672c\u7c7b\u578b\u6570\u636e\u5305\u88c5\u6210\u5bf9\u5e94\u7684\u5305\u88c5\u7c7b\u578b\u5bf9\u8c61\u3002\u4f8b\u5982\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>List&lt;Integer&gt; list = new ArrayList&lt;&gt;();\nlist.add(10); \/\/ \u81ea\u52a8\u88c5\u7bb1\uff0c\u5c06int\u7c7b\u578b\u768410\u88c5\u7bb1\u6210Integer\u5bf9\u8c61<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u7c7b\u4f3c\u5730\uff0c\u5f53\u6211\u4eec\u4ece\u6cdb\u578b\u5bb9\u5668\u4e2d\u83b7\u53d6\u5143\u7d20\u65f6\uff0c\u5982\u679c\u6cdb\u578b\u7c7b\u578b\u53c2\u6570\u662f\u5305\u88c5\u7c7b\u578b\uff0c\u800c\u6211\u4eec\u4f7f\u7528\u4e86\u5bf9\u5e94\u7684\u57fa\u672c\u7c7b\u578b\u53d8\u91cf\u6765\u63a5\u6536\u6570\u636e\uff0c\u7f16\u8bd1\u5668\u4f1a\u81ea\u52a8\u8fdb\u884c\u62c6\u7bb1\u64cd\u4f5c\uff0c\u5c06\u5305\u88c5\u7c7b\u578b\u5bf9\u8c61\u8f6c\u6362\u4e3a\u57fa\u672c\u7c7b\u578b\u6570\u636e\u3002\u4f8b\u5982\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>List&lt;Integer&gt; list = new ArrayList&lt;&gt;();\nlist.add(10);\nint value = list.get(0); \/\/ \u81ea\u52a8\u62c6\u7bb1\uff0c\u5c06Integer\u5bf9\u8c61\u8f6c\u6362\u4e3aint\u7c7b\u578b<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u81ea\u52a8\u88c5\u7bb1\u548c\u62c6\u7bb1\u7684\u64cd\u4f5c\u662f\u7531\u7f16\u8bd1\u5668\u5728\u7f16\u8bd1\u65f6\u81ea\u52a8\u5b8c\u6210\u7684\uff0c\u4f7f\u5f97\u6211\u4eec\u5728\u4f7f\u7528\u6cdb\u578b\u65f6\u53ef\u4ee5\u65b9\u4fbf\u5730\u5904\u7406\u57fa\u672c\u7c7b\u578b\u6570\u636e\u3002\u8fd9\u6837\uff0c\u6211\u4eec\u53ef\u4ee5\u50cf\u5904\u7406\u666e\u901a\u5bf9\u8c61\u4e00\u6837\u5904\u7406\u57fa\u672c\u7c7b\u578b\u6570\u636e\uff0c\u63d0\u9ad8\u4e86\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u548c\u7b80\u6d01\u6027\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"_13\u3001\u5728\u6cdb\u578b\u4e2d\u5982\u4f55\u8fdb\u884c\u7c7b\u578b\u8f6c\u6362\"><a href=\"#_13\u3001\u5728\u6cdb\u578b\u4e2d\u5982\u4f55\u8fdb\u884c\u7c7b\u578b\u8f6c\u6362\">13\u3001\u5728\u6cdb\u578b\u4e2d\u5982\u4f55\u8fdb\u884c\u7c7b\u578b\u8f6c\u6362\uff1f<\/a><\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u5728\u6cdb\u578b\u4e2d\u8fdb\u884c\u7c7b\u578b\u8f6c\u6362\u6709\u4e24\u79cd\u5e38\u89c1\u7684\u65b9\u5f0f\uff1a\u5f3a\u5236\u7c7b\u578b\u8f6c\u6362\u548c\u901a\u914d\u7b26\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u5f3a\u5236\u7c7b\u578b\u8f6c\u6362\uff1a\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u53ef\u80fd\u9700\u8981\u5c06\u6cdb\u578b\u5bf9\u8c61\u8f6c\u6362\u4e3a\u7279\u5b9a\u7684\u7c7b\u578b\u3002\u53ef\u4ee5\u4f7f\u7528\u5f3a\u5236\u7c7b\u578b\u8f6c\u6362\u6765\u5b9e\u73b0\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code>List&lt;Object&gt; list = new ArrayList&lt;&gt;();\nlist.add(\"Hello\");\nString str = (String) list.get(0); \/\/ \u5f3a\u5236\u7c7b\u578b\u8f6c\u6362\u4e3aString\u7c7b\u578b<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5728\u8fdb\u884c\u5f3a\u5236\u7c7b\u578b\u8f6c\u6362\u65f6\uff0c\u8981\u786e\u4fdd\u8f6c\u6362\u662f\u5b89\u5168\u7684\uff0c\u5373\u88ab\u8f6c\u6362\u7684\u5bf9\u8c61\u7684\u5b9e\u9645\u7c7b\u578b\u5fc5\u987b\u4e0e\u76ee\u6807\u7c7b\u578b\u517c\u5bb9\uff0c\u5426\u5219\u4f1a\u629b\u51faClassCastException\u5f02\u5e38\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u901a\u914d\u7b26\uff1a\u5982\u679c\u6211\u4eec\u4e0d\u786e\u5b9a\u6cdb\u578b\u53c2\u6570\u7684\u5177\u4f53\u7c7b\u578b\uff0c\u6216\u8005\u9700\u8981\u5728\u65b9\u6cd5\u4e2d\u5904\u7406\u4e0d\u540c\u7c7b\u578b\u7684\u6cdb\u578b\u53c2\u6570\uff0c\u53ef\u4ee5\u4f7f\u7528\u901a\u914d\u7b26\u6765\u8fdb\u884c\u7c7b\u578b\u8f6c\u6362\u3002\u901a\u914d\u7b26\u4f7f\u7528\u95ee\u53f7\uff08?\uff09\u8868\u793a\uff0c\u6709\u4e24\u79cd\u5e38\u89c1\u7684\u901a\u914d\u7b26\u7c7b\u578b\uff1a\u4e0a\u754c\u901a\u914d\u7b26\u548c\u65e0\u754c\u901a\u914d\u7b26\u3002<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4e0a\u754c\u901a\u914d\u7b26\uff08Upper Bounded Wildcard\uff09\u4f7f\u7528 extends \u5173\u952e\u5b57\u3002\u5b83\u8868\u793a\u6cdb\u578b\u53c2\u6570\u5fc5\u987b\u662f\u6307\u5b9a\u7c7b\u578b\u6216\u5176\u5b50\u7c7b\u578b\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public void processList(List&lt;? extends Number&gt; list) {\n    \/\/ \u5728\u8fd9\u91cc\u53ef\u4ee5\u5b89\u5168\u5730\u4f7f\u7528Number\u53ca\u5176\u5b50\u7c7b\u7684\u65b9\u6cd5\n}<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u65e0\u754c\u901a\u914d\u7b26\uff08Unbounded Wildcard\uff09\u4f7f\u7528\u95ee\u53f7\uff08?\uff09\u8868\u793a\uff0c\u8868\u793a\u6cdb\u578b\u53c2\u6570\u53ef\u4ee5\u662f\u4efb\u610f\u7c7b\u578b\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>public void processList(List&lt;?&gt; list) {\n    \/\/ \u5728\u8fd9\u91cc\u53ef\u4ee5\u5b89\u5168\u5730\u4f7f\u7528Object\u7c7b\u7684\u65b9\u6cd5\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f7f\u7528\u901a\u914d\u7b26\u53ef\u4ee5\u5728\u4e0d\u786e\u5b9a\u5177\u4f53\u7c7b\u578b\u7684\u60c5\u51b5\u4e0b\uff0c\u5bf9\u6cdb\u578b\u53c2\u6570\u8fdb\u884c\u5904\u7406\uff0c\u63d0\u9ad8\u4ee3\u7801\u7684\u7075\u6d3b\u6027\u548c\u53ef\u590d\u7528\u6027\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u901a\u914d\u7b26\u53ea\u80fd\u7528\u4e8e\u8bfb\u53d6\u6570\u636e\uff0c\u4e0d\u80fd\u7528\u4e8e\u5199\u5165\u6570\u636e\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5728\u4f7f\u7528\u901a\u914d\u7b26\u4f5c\u4e3a\u65b9\u6cd5\u53c2\u6570\u65f6\uff0c\u6211\u4eec\u53ea\u80fd\u4ece\u4e2d\u83b7\u53d6\u6570\u636e\uff0c\u4e0d\u80fd\u5411\u5176\u4e2d\u6dfb\u52a0\u6570\u636e\u3002\u5982\u679c\u9700\u8981\u540c\u65f6\u8bfb\u53d6\u548c\u5199\u5165\u6570\u636e\uff0c\u53ef\u4ee5\u4f7f\u7528\u6709\u754c\u901a\u914d\u7b26\uff08\u4f7f\u7528 super \u5173\u952e\u5b57\uff09\u6216\u8005\u4f7f\u7528\u6cdb\u578b\u53c2\u6570\u6765\u5b9e\u73b0\u3002<\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n","protected":false},"excerpt":{"rendered":"<p>1\u3001\u4ec0\u4e48\u662f\u679a\u4e3e\u7c7b\uff1f 2\u3001\u679a\u4e3e\u7c7b\u7684\u5e38\u91cf\u53ef\u4ee5\u6709\u81ea\u5df1\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\u5417\uff1f 3\u3001\u679a\u4e3e\u7c7b\u53ef\u4ee5\u5b9e\u73b0\u63a5\u53e3\u5417\uff1f 4\u3001\u5982\u4f55\u904d\u5386\u679a\u4e3e\u7c7b [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":234,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[103,104],"tags":[],"class_list":["post-1398","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java"],"_links":{"self":[{"href":"https:\/\/zero-zl.cn\/index.php\/wp-json\/wp\/v2\/posts\/1398","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zero-zl.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zero-zl.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zero-zl.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zero-zl.cn\/index.php\/wp-json\/wp\/v2\/comments?post=1398"}],"version-history":[{"count":1,"href":"https:\/\/zero-zl.cn\/index.php\/wp-json\/wp\/v2\/posts\/1398\/revisions"}],"predecessor-version":[{"id":1399,"href":"https:\/\/zero-zl.cn\/index.php\/wp-json\/wp\/v2\/posts\/1398\/revisions\/1399"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/zero-zl.cn\/index.php\/wp-json\/wp\/v2\/media\/234"}],"wp:attachment":[{"href":"https:\/\/zero-zl.cn\/index.php\/wp-json\/wp\/v2\/media?parent=1398"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zero-zl.cn\/index.php\/wp-json\/wp\/v2\/categories?post=1398"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zero-zl.cn\/index.php\/wp-json\/wp\/v2\/tags?post=1398"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}