{"id":203143,"date":"2025-05-22T08:15:54","date_gmt":"2025-05-22T00:15:54","guid":{"rendered":"https:\/\/server.hk\/cnblog\/203143\/"},"modified":"2025-05-22T08:15:54","modified_gmt":"2025-05-22T00:15:54","slug":"%e4%ba%86%e8%a7%a3-java-%e6%b5%81%e4%b8%ad%e7%9a%84%e7%bb%88%e7%ab%af%e4%b8%8e%e4%b8%ad%e9%97%b4%e8%bf%90%e7%ae%97%e7%ac%a6%ef%bc%9a%e4%b8%bb%e8%a6%81%e5%8c%ba%e5%88%ab%e5%92%8c%e7%a4%ba%e4%be%8b","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/203143\/","title":{"rendered":"\u4e86\u89e3 Java \u6d41\u4e2d\u7684\u7ec8\u7aef\u4e0e\u4e2d\u95f4\u8fd0\u7b97\u7b26\uff1a\u4e3b\u8981\u533a\u522b\u548c\u793a\u4f8b"},"content":{"rendered":"

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

\u4e86\u89e3 Java \u6d41\u4e2d\u7684\u7ec8\u7aef\u4e0e\u4e2d\u95f4\u8fd0\u7b97\u7b26\uff1a\u4e3b\u8981\u533a\u522b\u548c\u793a\u4f8b<\/h1>\n

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

\u5728\u6587\u7ae0\u5b9e\u6218\u5f00\u53d1\u7684\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u7ecf\u5e38\u4f1a\u9047\u5230\u4e00\u4e9b\u8fd9\u6837\u90a3\u6837\u7684\u95ee\u9898\uff0c\u7136\u540e\u8981\u5361\u597d\u534a\u5929\uff0c\u7b49\u95ee\u9898\u89e3\u51b3\u4e86\u624d\u53d1\u73b0\u539f\u6765\u4e00\u4e9b\u7ec6\u8282\u77e5\u8bc6\u70b9\u8fd8\u662f\u6ca1\u6709\u638c\u63e1\u597d\u3002\u4eca\u5929\u5c31\u6574\u7406\u5206\u4eab\u300a\u4e86\u89e3 Java \u6d41\u4e2d\u7684\u7ec8\u7aef\u4e0e\u4e2d\u95f4\u8fd0\u7b97\u7b26\uff1a\u4e3b\u8981\u533a\u522b\u548c\u793a\u4f8b\u300b\uff0c\u804a\u804a\uff0c\u5e0c\u671b\u53ef\u4ee5\u5e2e\u52a9\u5230\u6b63\u5728\u52aa\u529b\u8d5a\u94b1\u7684\u4f60\u3002<\/p>\n

<\/p>\n

1. java streams\u6982\u8ff0 <\/h2>\n

java streams \u5728 java 8 \u4e2d\u5f15\u5165\uff0c\u5141\u8bb8\u5bf9\u5143\u7d20\u5e8f\u5217\u8fdb\u884c\u51fd\u6570\u5f0f\u64cd\u4f5c\u3002\u5b83\u4eec\u63d0\u4f9b\u4e86\u4e00\u79cd\u4ee5\u66f4\u5177\u58f0\u660e\u6027\u548c\u53ef\u8bfb\u6027\u7684\u65b9\u5f0f\u5904\u7406\u6570\u636e\u96c6\u5408\u7684\u5f3a\u5927\u65b9\u6cd5\u3002 <\/p>\n

1.1 \u4ec0\u4e48\u662f\u7ec8\u7aef\u8fd0\u8425\u5546\uff1f <\/h3>\n

\u7ec8\u7aef\u8fd0\u7b97\u7b26\u662f\u6807\u8bb0\u6d41\u7ba1\u9053\u7ed3\u675f\u7684\u64cd\u4f5c\u3002\u5b83\u4eec\u89e6\u53d1\u6d41\u4e2d\u6570\u636e\u7684\u5904\u7406\u5e76\u4ea7\u751f\u7ed3\u679c\u6216\u526f\u4f5c\u7528\u3002\u4e00\u65e6\u8c03\u7528\u4e86\u7ec8\u7aef\u64cd\u4f5c\u7b26\uff0c\u6d41\u5c31\u88ab\u89c6\u4e3a\u5df2\u6d88\u8017\uff0c\u5e76\u4e14\u4e0d\u80fd\u5bf9\u5176\u6267\u884c\u8fdb\u4e00\u6b65\u7684\u64cd\u4f5c\u3002 <\/p>\n

\u7ec8\u7aef\u8fd0\u8425\u5546\u5e38\u89c1\u793a\u4f8b\uff1a<\/strong><\/p>\n

    \n
  • foreach()<\/strong>\uff1a\u8fed\u4ee3\u6bcf\u4e2a\u5143\u7d20\u5e76\u6267\u884c\u64cd\u4f5c\u3002<\/li>\n
  • collect()<\/strong>\uff1a\u5c06\u6d41\u4e2d\u7684\u5143\u7d20\u6536\u96c6\u5230\u96c6\u5408\u6216\u5176\u4ed6\u5f62\u5f0f\u3002<\/li>\n
  • reduce()<\/strong>\uff1a\u5c06\u6d41\u7684\u5143\u7d20\u7ec4\u5408\u6210\u5355\u4e2a\u7ed3\u679c\u3002<\/li>\n
  • count()<\/strong>\uff1a\u8ba1\u7b97\u6d41\u4e2d\u5143\u7d20\u7684\u6570\u91cf\u3002<\/li>\n<\/ul>\n

    \u793a\u4f8b\u4ee3\u7801\uff1a<\/strong><\/p>\n

    import java.util.arrays;\nimport java.util.list;\nimport java.util.stream.collectors;\n\npublic class terminaloperatorexample {\n    public static void main(string[] args) {\n        list<string> names = arrays.aslist(\"alice\", \"bob\", \"charlie\");\n\n        \/\/ terminal operator: foreach\n        names.stream().foreach(name -> system.out.println(\"name: \" + name));\n\n        \/\/ terminal operator: collect\n        list<string> filterednames = names.stream()\n                                           .filter(name -> name.startswith(\"a\"))\n                                           .collect(collectors.tolist());\n        system.out.println(\"filtered names: \" + filterednames);\n    }\n}\n<\/pre>\n
    \u6f14\u793a\u7ed3\u679c\uff1a<\/strong><\/p>\n
    name: alice\nname: bob\nname: charlie\nfiltered names: [alice]\n<\/pre>\n
     1.2 \u4ec0\u4e48\u662f\u4e2d\u95f4\u7b97\u5b50\uff1f <\/h3>\n
    \u4e2d\u95f4\u8fd0\u7b97\u7b26\u662f\u5c06\u4e00\u4e2a\u6d41\u8f6c\u6362\u4e3a\u53e6\u4e00\u4e2a\u6d41\u7684\u64cd\u4f5c\u3002\u5728\u8c03\u7528\u7ec8\u7aef\u64cd\u4f5c\u5458\u4e4b\u524d\uff0c\u5b83\u4eec\u4e0d\u4f1a\u89e6\u53d1\u4efb\u4f55\u5904\u7406\u3002\u8fd9\u4e9b\u8fd0\u7b97\u7b26\u7528\u4e8e\u6784\u5efa\u64cd\u4f5c\u7ba1\u9053\uff0c\u4ece\u800c\u5b9e\u73b0\u9ad8\u6548\u7684\u6570\u636e\u5904\u7406\u548c\u64cd\u4f5c\u3002 <\/p>\n
    \u4e2d\u95f4\u8fd0\u7b97\u7b26\u7684\u5e38\u89c1\u793a\u4f8b\uff1a<\/strong><\/p>\n
      \n
    •  filter()<\/strong>\uff1a\u6839\u636e\u8c13\u8bcd\u8fc7\u6ee4\u5143\u7d20\u3002<\/li>\n
    •  map()<\/strong>\uff1a\u4f7f\u7528\u51fd\u6570\u8f6c\u6362\u6bcf\u4e2a\u5143\u7d20\u3002<\/li>\n
    •  sorted()<\/strong>\uff1a\u6839\u636e\u6bd4\u8f83\u5668\u5bf9\u5143\u7d20\u8fdb\u884c\u6392\u5e8f\u3002<\/li>\n
    •  distinct()<\/strong>\uff1a\u5220\u9664\u91cd\u590d\u5143\u7d20\u3002<\/li>\n<\/ul>\n
      \u793a\u4f8b\u4ee3\u7801\uff1a<\/strong><\/p>\n
      import java.util.arrays;\nimport java.util.list;\nimport java.util.stream.collectors;\n\npublic class intermediateoperatorexample {\n    public static void main(string[] args) {\n        list<string> names = arrays.aslist(\"alice\", \"bob\", \"charlie\", \"alice\");\n\n        \/\/ intermediate operators: filter and map\n        list<string> transformednames = names.stream()\n                                              .filter(name -> name.startswith(\"a\"))\n                                              .map(string::touppercase)\n                                              .distinct()\n                                              .collect(collectors.tolist());\n        system.out.println(\"transformed names: \" + transformednames);\n    }\n}\n<\/pre>\n
      \u6f14\u793a\u7ed3\u679c\uff1a<\/strong><\/p>\n
      Transformed Names: [ALICE]\n<\/pre>\n
       2. \u7ec8\u7aef\u8fd0\u8425\u5546\u548c\u4e2d\u95f4\u8fd0\u8425\u5546\u4e4b\u95f4\u7684\u4e3b\u8981\u533a\u522b <\/h2>\n
      \u4e86\u89e3\u8fd9\u4e9b\u8fd0\u7b97\u7b26\u4e4b\u95f4\u7684\u5dee\u5f02\u5bf9\u4e8e\u6709\u6548\u7684\u6d41\u5904\u7406\u81f3\u5173\u91cd\u8981\u3002 <\/p>\n
       2.1 \u76ee\u7684\u548c\u529f\u80fd <\/h3>\n
        \n
      •  \u7ec8\u7aef\u64cd\u4f5c\u7b26<\/strong>\uff1a\u7ed3\u675f\u6d41\u7ba1\u9053\uff0c\u89e6\u53d1\u5904\u7406\uff0c\u5e76\u4ea7\u751f\u7ed3\u679c\u6216\u526f\u4f5c\u7528\u3002\u5b83\u4eec\u65e8\u5728\u6267\u884c\u64cd\u4f5c\u5e76\u4ece\u6d41\u4e2d\u751f\u6210\u8f93\u51fa\u3002<\/li>\n
      •  \u4e2d\u95f4\u8fd0\u7b97\u7b26<\/strong>\uff1a\u5c06\u6d41\u8f6c\u6362\u4e3a\u53e6\u4e00\u4e2a\u6d41\uff0c\u800c\u4e0d\u5bf9\u6570\u636e\u8fdb\u884c\u4efb\u4f55\u5904\u7406\u3002\u5b83\u4eec\u7528\u4e8e\u521b\u5efa\u64cd\u4f5c\u7ba1\u9053\uff0c\u4e00\u65e6\u8c03\u7528\u7ec8\u7aef\u64cd\u4f5c\u7b26\u5c31\u4f1a\u6267\u884c\u8fd9\u4e9b\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n
         2.2 \u6267\u884c\u4e0e\u6027\u80fd <\/h3>\n
          \n
        •  \u7ec8\u7aef\u64cd\u4f5c\u7b26<\/strong>\uff1a\u5bfc\u81f4\u6574\u4e2a\u6d41\u7ba1\u9053\u7684\u5904\u7406\u3002\u5b83\u4eec\u4ec5\u6267\u884c\u4e00\u6b21\uff0c\u5e76\u4e14\u6839\u636e\u64cd\u4f5c\u7684\u4e0d\u540c\uff0c\u8ba1\u7b97\u6210\u672c\u53ef\u80fd\u4f1a\u5f88\u9ad8\u3002<\/li>\n
        •  \u4e2d\u95f4\u8fd0\u7b97\u7b26<\/strong>\uff1a\u662f\u60f0\u6027\u7684\uff0c\u5728\u8c03\u7528\u7ec8\u7aef\u8fd0\u7b97\u7b26\u4e4b\u524d\u4e0d\u6267\u884c\u4efb\u4f55\u5904\u7406\u3002\u8fd9\u5141\u8bb8\u9ad8\u6548\u7684\u64cd\u4f5c\u94fe\u63a5\uff0c\u800c\u65e0\u9700\u4e0d\u5fc5\u8981\u7684\u8ba1\u7b97\u3002<\/li>\n<\/ul>\n
           2.3 \u53ef\u53d8\u6027\u548c\u72b6\u6001 <\/h3>\n
            \n
          •  \u7ec8\u7aef\u64cd\u4f5c\u7b26<\/strong>\uff1a\u53ef\u80fd\u4f1a\u4ea7\u751f\u526f\u4f5c\u7528\u6216\u4fee\u6539\u5916\u90e8\u72b6\u6001\u3002\u4f8b\u5982\uff0cforeach() \u53ef\u4ee5\u5c06\u5143\u7d20\u6253\u5370\u5230\u63a7\u5236\u53f0\u6216\u66f4\u65b0\u5916\u90e8\u96c6\u5408\u3002<\/li>\n
          •  \u4e2d\u95f4\u8fd0\u7b97\u7b26<\/strong>\uff1a\u65e0\u72b6\u6001\uff0c\u4e0d\u4fee\u6539\u5916\u90e8\u72b6\u6001\u3002\u5b83\u4eec\u4ec5\u5904\u7406\u6d41\u4e2d\u7684\u6570\u636e\u5e76\u751f\u6210\u65b0\u7684\u6d41\u4f5c\u4e3a\u8f93\u51fa\u3002<\/li>\n<\/ul>\n
             \u4e09\u3001\u7ed3\u8bba <\/h2>\n
            \u4e86\u89e3 java streams \u4e2d\u7684\u7ec8\u7aef\u548c\u4e2d\u95f4\u8fd0\u7b97\u7b26\u5bf9\u4e8e\u7f16\u5199\u9ad8\u6548\u4e14\u53ef\u8bfb\u7684\u4ee3\u7801\u81f3\u5173\u91cd\u8981\u3002\u7ec8\u7aef\u7b97\u5b50\u5b8c\u6210\u6d41\u5904\u7406\u7ba1\u9053\uff0c\u800c\u4e2d\u95f4\u7b97\u5b50\u6784\u5efa\u548c\u8f6c\u6362\u7ba1\u9053\u3002\u901a\u8fc7\u6709\u6548\u5730\u5229\u7528\u8fd9\u4e9b\u8fd0\u7b97\u7b26\uff0c\u60a8\u53ef\u4ee5\u4ee5\u66f4\u5177\u58f0\u660e\u6027\u548c\u529f\u80fd\u6027\u7684\u65b9\u5f0f\u5904\u7406\u6570\u636e\u5904\u7406\u4efb\u52a1\u3002 <\/p>\n
            \u5982\u679c\u60a8\u6709\u4efb\u4f55\u7591\u95ee\u6216\u9700\u8981\u8fdb\u4e00\u6b65\u8bf4\u660e\uff0c\u8bf7\u968f\u65f6\u5728\u4e0b\u9762\u8bc4\u8bba\uff01 <\/p>\n
            \u9605\u8bfb\u66f4\u591a\u6587\u7ae0<\/strong>\uff1a\u4e86\u89e3 java \u6d41\u4e2d\u7684\u7ec8\u7aef\u4e0e\u4e2d\u95f4\u8fd0\u7b97\u7b26\uff1a\u4e3b\u8981\u5dee\u5f02\u548c\u793a\u4f8b<\/p>\n
            \u672c\u7bc7\u5173\u4e8e\u300a\u4e86\u89e3 Java \u6d41\u4e2d\u7684\u7ec8\u7aef\u4e0e\u4e2d\u95f4\u8fd0\u7b97\u7b26\uff1a\u4e3b\u8981\u533a\u522b\u548c\u793a\u4f8b\u300b\u7684\u4ecb\u7ecd\u5c31\u5230\u6b64\u7ed3\u675f\u5566\uff0c\u4f46\u662f\u5b66\u65e0\u6b62\u5883\uff0c\u60f3\u8981\u4e86\u89e3\u5b66\u4e60\u66f4\u591a\u5173\u4e8e\u6587\u7ae0\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u8bf7\u5173\u6ce8\u516c\u4f17\u53f7\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":"
            \u4e86\u89e3 Java \u6d41\u4e2d\u7684\u7ec8\u7aef\u4e0e\u4e2d\u95f4...<\/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-203143","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/203143","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=203143"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/203143\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=203143"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=203143"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=203143"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}