{"id":203202,"date":"2025-05-22T10:33:36","date_gmt":"2025-05-22T02:33:36","guid":{"rendered":"https:\/\/server.hk\/cnblog\/203202\/"},"modified":"2025-05-22T10:33:36","modified_gmt":"2025-05-22T02:33:36","slug":"%e9%9b%86%e5%90%88%e3%80%81%e6%8e%92%e5%ba%8f%e5%92%8c%e5%ae%9e%e7%94%a8%e6%96%b9%e6%b3%95%e4%b8%ad%e7%9a%84%e9%83%a8%e5%88%86%e6%b3%9b%e5%9e%8b","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/203202\/","title":{"rendered":"\u96c6\u5408\u3001\u6392\u5e8f\u548c\u5b9e\u7528\u65b9\u6cd5\u4e2d\u7684\u90e8\u5206\u6cdb\u578b"},"content":{"rendered":"

<\/b> <\/p>\n

\u96c6\u5408\u3001\u6392\u5e8f\u548c\u5b9e\u7528\u65b9\u6cd5\u4e2d\u7684\u90e8\u5206\u6cdb\u578b<\/h1>\n

<\/i>\u6536\u85cf<\/span> <\/p>\n

\u4ece\u73b0\u5728\u5f00\u59cb\uff0c\u52aa\u529b\u5b66\u4e60\u5427\uff01\u672c\u6587\u300a\u96c6\u5408\u3001\u6392\u5e8f\u548c\u5b9e\u7528\u65b9\u6cd5\u4e2d\u7684\u90e8\u5206\u6cdb\u578b\u300b<\/span>\u4e3b\u8981\u8bb2\u89e3\u4e86<\/span>\u7b49\u7b49\u76f8\u5173\u77e5\u8bc6\u70b9\uff0c\u6211\u4f1a\u5728\u4e2d\u6301\u7eed\u66f4\u65b0\u76f8\u5173\u7684\u7cfb\u5217\u6587\u7ae0\uff0c\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u5e76\u79ef\u6781\u7559\u8a00\u5efa\u8bae\u3002\u4e0b\u9762\u5c31\u5148\u4e00\u8d77\u6765\u770b\u4e00\u4e0b\u672c\u7bc7\u6b63\u6587\u5185\u5bb9\u5427\uff0c\u5e0c\u671b\u80fd\u5e2e\u5230\u4f60\uff01<\/p>\n

<\/p>\n

\u5728\u8fd9\u7bc7\u540e\u7eed\u6587\u7ae0\u4e2d\uff0c\u6211\u4eec\u5c06\u5b8c\u5168\u5173\u6ce8\u96c6\u5408\u4e2d\u7684\u6cdb\u578b<\/strong>\u3001java \u96c6\u5408\u4e2d\u7c7b\u578b\u5b89\u5168\u7684\u6982\u5ff5\uff0c\u4ee5\u53ca\u6cdb\u578b\u5982\u4f55\u4f7f\u60a8\u7684\u4ee3\u7801\u66f4\u52a0\u7075\u6d3b\u548c\u5065\u58ee\u3002\u6b64\u5916\uff0c\u6211\u4eec\u5c06\u63a2\u7d22\u6392\u5e8f\u5982\u4f55\u4e0e\u901a\u7528\u96c6\u5408\u4e00\u8d77\u4f7f\u7528\u4ee5\u53ca\u4e00\u4e9b\u6d3e\u4e0a\u7528\u573a\u7684\u9ad8\u7ea7\u5b9e\u7528\u65b9\u6cd5\u3002<\/p>\n

\u2014<\/p>\n

\u76ee\u5f55 <\/h3>\n
    \n
  1. \u6cdb\u578b\u7b80\u4ecb<\/li>\n
  2. \u5217\u8868\u4e2d\u7684\u6cdb\u578b<\/li>\n
  3. \u96c6\u5408\u4e2d\u7684\u6cdb\u578b<\/li>\n
  4. \u5730\u56fe\u4e2d\u7684\u6cdb\u578b<\/li>\n
  5. \u4f7f\u7528\u6cdb\u578b\u6392\u5e8f<\/li>\n
  6. \u9ad8\u7ea7\u5b9e\u7528\u65b9\u6cd5<\/li>\n
  7. \u5e38\u89c1\u7684\u6cdb\u578b\u9519\u8bef<\/li>\n
  8. \u6311\u6218<\/li>\n
  9. \u7ed3\u8bba<\/li>\n<\/ol>\n

    \u2014<\/p>\n

    \u6cdb\u578b\u7b80\u4ecb <\/h3>\n

    java \u4e2d\u7684 <\/p>\n

    \u6cdb\u578b<\/strong> \u5141\u8bb8\u60a8\u7f16\u5199\u9002\u7528\u4e8e\u4efb\u4f55\u6570\u636e\u7c7b\u578b\u7684\u7c7b\u3001\u63a5\u53e3\u6216\u65b9\u6cd5\u3002\u901a\u8fc7\u5c06\u6cdb\u578b\u4e0e\u96c6\u5408\u7ed3\u5408\u4f7f\u7528\uff0c\u53ef\u4ee5\u786e\u4fdd\u7f16\u8bd1\u65f6\u7684\u7c7b\u578b\u5b89\u5168<\/strong>\u3002\u8fd9\u610f\u5473\u7740\u60a8\u53ef\u4ee5\u907f\u514d\u6f5c\u5728\u7684 classcastexception \u9519\u8bef\u5e76\u6d88\u9664\u663e\u5f0f\u8f6c\u6362\u7684\u9700\u8981\u3002<\/p>\n

    \u4f8b\u5982\uff1a<\/p>\n

    list<string> strings = new arraylist<>();\nstrings.add(\"hello\");\n\/\/ adding a non-string value will now cause a compile-time error.\n<\/pre>\n
    \u6cdb\u578b\u786e\u4fdd\u53ea\u6709\u6307\u5b9a\u7684\u6570\u636e\u7c7b\u578b\u53ef\u4ee5\u5b58\u50a8\u5728\u96c6\u5408\u4e2d\uff0c\u9632\u6b62\u8fd0\u884c\u65f6\u95ee\u9898\u5e76\u4f7f\u4ee3\u7801\u66f4\u5177\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u3002<\/p>\n
    \u2014<\/p>\n
     \u5217\u8868\u4e2d\u7684\u6cdb\u578b <\/h3>\n
    \u5217\u8868\u4e2d\u7684\u6cdb\u578b\u786e\u4fdd\u60a8\u53ea\u80fd\u5b58\u50a8\u6307\u5b9a\u7c7b\u578b\u7684\u5bf9\u8c61\u3002\u4f8b\u5982\uff0clist<string> \u53ea\u5141\u8bb8 string \u5bf9\u8c61\uff0c\u800c list<integer> \u53ea\u5141\u8bb8 integer \u5bf9\u8c61\u3002<\/p>\n
     \u4ee3\u7801\u793a\u4f8b <\/h4>\n
    import java.util.arraylist;\nimport java.util.list;\n\npublic class genericlistexample {\n    public static void main(string[] args) {\n        list<string> names = new arraylist<>();\n        names.add(\"alice\");\n        names.add(\"bob\");\n\n        \/\/ the following line would cause a compile-time error:\n        \/\/ names.add(123); \/\/ error: cannot add integer to list<string>\n\n        for (string name : names) {\n            system.out.println(name);\n        }\n    }\n}\n<\/pre>\n
     \u597d\u5904 <\/h4>\n
      \n
    •  \u7c7b\u578b\u5b89\u5168<\/strong>\uff1a\u7f16\u8bd1\u5668\u5c06\u5f3a\u5236\u53ea\u6709\u58f0\u660e\u7c7b\u578b\u7684\u5bf9\u8c61\u624d\u80fd\u6dfb\u52a0\u5230\u5217\u8868\u4e2d\u3002<\/li>\n
    •  \u65e0\u663e\u5f0f\u8f6c\u6362<\/strong>\uff1a\u4ece\u5217\u8868\u4e2d\u68c0\u7d22\u5143\u7d20\u65f6\u65e0\u9700\u8fdb\u884c\u8f6c\u6362\u3002<\/li>\n<\/ul>\n
      \u2014<\/p>\n
       \u96c6\u5408\u4e2d\u7684\u6cdb\u578b <\/h3>\n
      \u5177\u6709\u6cdb\u578b\u7684\u96c6\u5408\u7684\u5de5\u4f5c\u65b9\u5f0f\u4e0e\u5217\u8868\u7c7b\u4f3c\uff0c\u786e\u4fdd\u6240\u6709\u5143\u7d20\u90fd\u5c5e\u4e8e\u7279\u5b9a\u7c7b\u578b\u3002<\/p>\n
       \u4ee3\u7801\u793a\u4f8b <\/h4>\n
      import java.util.hashset;\nimport java.util.set;\n\npublic class genericsetexample {\n    public static void main(string[] args) {\n        set<integer> numbers = new hashset<>();\n        numbers.add(10);\n        numbers.add(20);\n        numbers.add(30);\n\n        \/\/ compile-time error if a non-integer is added:\n        \/\/ numbers.add(\"forty\"); \/\/ error\n\n        for (integer num : numbers) {\n            system.out.println(num);\n        }\n    }\n}\n<\/pre>\n
       \u597d\u5904 <\/h4>\n
        \n
      • \u60a8\u4ee5\u7c7b\u578b\u5b89\u5168\u7684\u65b9\u5f0f\u7ef4\u62a4\u5143\u7d20\u7684\u552f\u4e00\u6027\u3002<\/li>\n
      • \u786e\u4fdd\u4e0d\u6dfb\u52a0\u4efb\u4f55\u610f\u5916\u7684\u7c7b\u578b\u3002<\/li>\n<\/ul>\n
        \u2014<\/p>\n
         \u5730\u56fe\u4e2d\u7684\u6cdb\u578b <\/h3>\n
        \u6620\u5c04\u662f\u952e\u503c\u5bf9\uff0c\u652f\u6301\u952e\u548c\u503c\u7684\u6cdb\u578b\u3002\u4f8b\u5982\uff0cmap<string\u3001integer> \u5c06\u5f3a\u5236\u952e\u4e3a string\uff0c\u503c\u4e3a integer\u3002<\/p>\n
         \u4ee3\u7801\u793a\u4f8b <\/h4>\n
        import java.util.hashmap;\nimport java.util.map;\n\npublic class genericmapexample {\n    public static void main(string[] args) {\n        map<string, integer> phonebook = new hashmap<>();\n        phonebook.put(\"alice\", 12345);\n        phonebook.put(\"bob\", 67890);\n\n        \/\/ the following would cause a compile-time error:\n        \/\/ phonebook.put(123, \"charlie\"); \/\/ error\n\n        for (map.entry<string, integer> entry : phonebook.entryset()) {\n            system.out.println(entry.getkey() + \": \" + entry.getvalue());\n        }\n    }\n}\n<\/pre>\n
         \u597d\u5904 <\/h4>\n
          \n
        • \u60a8\u53ef\u4ee5\u786e\u4fdd map \u4e2d\u7684\u952e\u548c\u503c\u7684\u7c7b\u578b\u5b89\u5168\u3002<\/li>\n
        • \u9632\u6b62\u6df7\u5408\u7c7b\u578b\u9020\u6210\u6f5c\u5728\u7684\u8fd0\u884c\u65f6\u9519\u8bef\u3002<\/li>\n<\/ul>\n
          \u2014<\/p>\n
           \u4f7f\u7528\u6cdb\u578b\u6392\u5e8f <\/h3>\n
          \u5bf9\u901a\u7528\u96c6\u5408\u8fdb\u884c\u6392\u5e8f\u975e\u5e38\u7b80\u5355\uff0c\u53ef\u4ee5\u4f7f\u7528 collections.sort() \u8fdb\u884c\u5217\u8868\u6392\u5e8f\uff0c\u4f7f\u7528 comparable \u6216 comparator \u8fdb\u884c\u81ea\u5b9a\u4e49\u6392\u5e8f\u3002<\/p>\n
           \u4ee3\u7801\u793a\u4f8b <\/h4>\n
          import java.util.arraylist;\nimport java.util.collections;\nimport java.util.list;\n\npublic class genericsortingexample {\n    public static void main(string[] args) {\n        list<integer> numbers = new arraylist<>();\n        numbers.add(5);\n        numbers.add(3);\n        numbers.add(8);\n        numbers.add(1);\n\n        collections.sort(numbers); \/\/ sorts in natural order\n        system.out.println(\"sorted numbers: \" + numbers);\n    }\n}\n<\/pre>\n
          \u5bf9\u4e8e\u81ea\u5b9a\u4e49\u6392\u5e8f\uff0c\u60a8\u53ef\u4ee5\u5b9e\u73b0 comparator \u63a5\u53e3\u3002<\/p>\n
          \u2014<\/p>\n
           \u9ad8\u7ea7\u5b9e\u7528\u65b9\u6cd5 <\/h3>\n
          \u96c6\u5408\u5b9e\u7528\u7a0b\u5e8f\u7c7b\u8fd8\u652f\u6301\u4e8c\u5206\u641c\u7d22<\/strong>\u3001\u968f\u673a\u64ad\u653e<\/strong>\u3001\u53cd\u5411<\/strong>\u548c\u9891\u7387\u8ba1\u6570<\/strong>\u7b49\u64cd\u4f5c\u3002\u8fd9\u4e9b\u64cd\u4f5c\u53ef\u4ee5\u5e94\u7528\u4e8e\u901a\u7528\u96c6\u5408\u4ee5\u8fdb\u884c\u66f4\u5f3a\u5927\u7684\u6570\u636e\u64cd\u4f5c\u3002<\/p>\n
           \u4ee3\u7801\u793a\u4f8b <\/h4>\n
          import java.util.arraylist;\nimport java.util.collections;\nimport java.util.list;\n\npublic class utilitymethodsexample {\n    public static void main(string[] args) {\n        list<string> items = new arraylist<>();\n        items.add(\"apple\");\n        items.add(\"banana\");\n        items.add(\"cherry\");\n\n        \/\/ shuffle the list\n        collections.shuffle(items);\n        system.out.println(\"shuffled list: \" + items);\n\n        \/\/ reverse the list\n        collections.reverse(items);\n        system.out.println(\"reversed list: \" + items);\n\n        \/\/ frequency of an item\n        int freq = collections.frequency(items, \"apple\");\n        system.out.println(\"frequency of apple: \" + freq);\n    }\n}\n<\/pre>\n
          \u2014<\/p>\n
           \u5e38\u89c1\u7684\u6cdb\u578b\u9519\u8bef <\/h3>\n
            \n
          •  \u4f7f\u7528\u539f\u59cb\u7c7b\u578b<\/strong>\uff1a\u4f7f\u7528\u96c6\u5408\u65f6\u59cb\u7ec8\u6307\u5b9a\u7c7b\u578b\u53c2\u6570\uff0c\u4ee5\u907f\u514d\u6f5c\u5728\u7684\u8fd0\u884c\u65f6\u95ee\u9898\u3002 <\/li>\n<\/ul>\n
              List list = new ArrayList(); \/\/ Raw type\n  list.add(\"String\");\n  list.add(123); \/\/ No compile-time error, but may cause runtime issues\n<\/pre>\n
              \n
            •  \u9519\u8bef\u5730\u4f7f\u7528\u901a\u914d\u7b26<\/strong>\uff1a\u5c06\u96c6\u5408\u4f20\u9012\u7ed9\u65b9\u6cd5\u65f6\uff0c\u4f7f\u7528\u901a\u914d\u7b26\u5982list<?> \u6216list<\uff1f\u6269\u5c55 number> \u53ef\u80fd\u4f1a\u5f15\u8d77\u6df7\u4e71\u3002\u4e86\u89e3\u4ec0\u4e48\u65f6\u5019\u4f7f\u7528\uff1f\u4ee5\u53ca extends \u6216 super \u5173\u952e\u5b57\u3002<\/li>\n<\/ul>\n
              \u2014<\/p>\n
               \u6311\u6218 <\/h3>\n
               \u6311\u6218 1\uff1a\u901a\u7528\u5806\u6808 <\/h4>\n
              \u4f7f\u7528\u6cdb\u578b\u5b9e\u73b0\u4e00\u4e2a\u7b80\u5355\u7684\u5806\u6808\u7c7b\u3002\u5806\u6808\u5e94\u8be5\u652f\u6301\u63a8\u9001\u5143\u7d20\u3001\u5f39\u51fa\u5143\u7d20\u4ee5\u53ca\u68c0\u67e5\u662f\u5426\u4e3a\u7a7a\u3002<\/p>\n
               \u6311\u6218 2\uff1a\u5bf9\u81ea\u5b9a\u4e49\u5bf9\u8c61\u8fdb\u884c\u6392\u5e8f <\/h4>\n
              \u521b\u5efa\u81ea\u5b9a\u4e49\u5bf9\u8c61\u5217\u8868\uff0c\u4f8b\u5982\u4eba\u5458\uff0c\u5e76\u6839\u636e\u5e74\u9f84\u6216\u59d3\u540d\u7b49\u81ea\u5b9a\u4e49\u5b57\u6bb5\u5bf9\u5176\u8fdb\u884c\u6392\u5e8f\u3002<\/p>\n
              \u2014<\/p>\n
               \u7ed3\u8bba <\/h3>\n
              \u5728\u8fd9\u7bc7\u6587\u7ae0\u4e2d\uff0c\u6211\u4eec\u63a2\u8ba8\u4e86\u5982\u4f55\u4f7f\u7528\u96c6\u5408\u4e2d\u7684\u6cdb\u578b<\/strong>\u6765\u5b9e\u73b0\u7c7b\u578b\u5b89\u5168\u3001\u7075\u6d3b\u6027\u548c\u6613\u7528\u6027\u3002\u6211\u4eec\u8fd8\u8ba8\u8bba\u4e86\u6392\u5e8f\u548c\u9ad8\u7ea7\u5b9e\u7528\u65b9\u6cd5\uff0c\u4f7f\u96c6\u5408\u7684\u5904\u7406\u66f4\u52a0\u9ad8\u6548\u3002\u901a\u8fc7\u638c\u63e1\u6cdb\u578b\uff0c\u60a8\u53ef\u4ee5\u7f16\u5199\u66f4\u5065\u58ee\u3001\u65e0\u9519\u8bef\u4e14\u9ad8\u5ea6\u53ef\u91cd\u7528\u7684\u4ee3\u7801\u3002<\/p>\n
              \u2014 <\/p>\n
              \u7406\u8bba\u8981\u638c\u63e1\uff0c\u5b9e\u64cd\u4e0d\u80fd\u843d\uff01\u4ee5\u4e0a\u5173\u4e8e\u300a\u96c6\u5408\u3001\u6392\u5e8f\u548c\u5b9e\u7528\u65b9\u6cd5\u4e2d\u7684\u90e8\u5206\u6cdb\u578b\u300b\u7684\u8be6\u7ec6\u4ecb\u7ecd\uff0c\u5927\u5bb6\u90fd\u638c\u63e1\u4e86\u5427\uff01\u5982\u679c\u60f3\u8981\u7ee7\u7eed\u63d0\u5347\u81ea\u5df1\u7684\u80fd\u529b\uff0c\u90a3\u4e48\u5c31\u6765\u5173\u6ce8\u516c\u4f17\u53f7\u5427\uff01<\/p>\n
                    \u7248\u672c\u58f0\u660e \u672c\u6587\u8f6c\u8f7d\u4e8e\uff1adev.to \u5982\u6709\u4fb5\u72af\uff0c\u8bf7\u8054\u7cfb\u5220\u9664<\/p>\n","protected":false},"excerpt":{"rendered":"
              \u96c6\u5408\u3001\u6392\u5e8f\u548c\u5b9e\u7528\u65b9\u6cd5\u4e2d\u7684\u90e8\u5206\u6cdb\u578b...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-203202","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/203202","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=203202"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/203202\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=203202"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=203202"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=203202"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}