{"id":202707,"date":"2025-05-22T08:31:51","date_gmt":"2025-05-22T00:31:51","guid":{"rendered":"https:\/\/server.hk\/cnblog\/202707\/"},"modified":"2025-05-22T08:31:51","modified_gmt":"2025-05-22T00:31:51","slug":"java%e5%87%bd%e6%95%b0%e5%bc%8f%e7%bc%96%e7%a8%8b%e5%9c%a8%e6%95%b0%e6%8d%ae%e5%a4%84%e7%90%86%e4%b8%ad%e5%a6%82%e4%bd%95%e6%8f%90%e9%ab%98%e6%80%a7%e8%83%bd%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/202707\/","title":{"rendered":"Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u5728\u6570\u636e\u5904\u7406\u4e2d\u5982\u4f55\u63d0\u9ad8\u6027\u80fd\uff1f"},"content":{"rendered":"

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

Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u5728\u6570\u636e\u5904\u7406\u4e2d\u5982\u4f55\u63d0\u9ad8\u6027\u80fd\uff1f<\/h1>\n

\u77e5\u8bc6\u70b9\u638c\u63e1\u4e86\uff0c\u8fd8\u9700\u8981\u4e0d\u65ad\u7ec3\u4e60\u624d\u80fd\u719f\u7ec3\u8fd0\u7528\u3002\u4e0b\u9762\u7ed9\u5927\u5bb6\u5e26\u6765\u4e00\u4e2a\u6587\u7ae0\u5f00\u53d1\u5b9e\u6218\uff0c\u624b\u628a\u624b\u6559\u5927\u5bb6\u5b66\u4e60\u300aJava\u51fd\u6570\u5f0f\u7f16\u7a0b\u5728\u6570\u636e\u5904\u7406\u4e2d\u5982\u4f55\u63d0\u9ad8\u6027\u80fd\uff1f\u300b\uff0c\u5728\u5b9e\u73b0\u529f\u80fd\u7684\u8fc7\u7a0b\u4e2d\u4e5f\u5e26\u5927\u5bb6\u91cd\u65b0\u6e29\u4e60\u76f8\u5173\u77e5\u8bc6\u70b9\uff0c\u6e29\u6545\u800c\u77e5\u65b0\uff0c\u56de\u5934\u770b\u770b\u8bf4\u4e0d\u5b9a\u53c8\u6709\u4e0d\u4e00\u6837\u7684\u611f\u609f\uff01<\/p>\n

Java \u51fd\u6570\u5f0f\u7f16\u7a0b\u901a\u8fc7\u4e0d\u53ef\u53d8\u6027\u907f\u514d\u5e76\u53d1\u63a7\u5236\u3001\u5229\u7528\u9ad8\u9636\u51fd\u6570\u8fdb\u884c\u9ad8\u7ea7\u62bd\u8c61\uff0c\u5728\u6570\u636e\u5904\u7406\u4e2d\u53ef\u663e\u8457\u63d0\u5347\u6027\u80fd\u3002\u5b9e\u8df5\u4e2d\uff0c\u901a\u8fc7\u5229\u7528\u5e76\u884c\u5316\u7684\u6d41 API \u5904\u7406\u6570\u636e\u96c6\uff0c\u5982\u6309\u65e5\u671f\u805a\u5408\u9500\u552e\u603b\u989d\uff0c\u51fd\u6570\u5f0f\u65b9\u6cd5\u53ef\u6d88\u9664\u663e\u5f0f\u904d\u5386\u9700\u6c42\uff0c\u4ece\u800c\u4f18\u5316\u5927\u6570\u636e\u96c6\u5904\u7406\u6548\u7387\u3002<\/p>\n

<\/p>\n

Java \u51fd\u6570\u5f0f\u7f16\u7a0b\u5728\u6570\u636e\u5904\u7406\u4e2d\u7684\u6027\u80fd\u63d0\u5347<\/strong><\/p>\n

\u51fd\u6570\u5f0f\u7f16\u7a0b\u662f\u4e00\u79cd\u7f16\u7a0b\u8303\u5f0f\uff0c\u5b83\u91cd\u89c6\u4e0d\u53ef\u53d8\u6027\u548c\u9ad8\u9636\u51fd\u6570\u7684\u4f7f\u7528\u3002\u5728\u6570\u636e\u5904\u7406\u4e2d\uff0c\u51fd\u6570\u5f0f\u7f16\u7a0b\u53ef\u4ee5\u663e\u8457\u63d0\u9ad8\u6027\u80fd\uff0c\u4f7f\u5176\u6210\u4e3a\u5904\u7406\u5927\u6570\u636e\u96c6\u7684\u7406\u60f3\u9009\u62e9\u3002<\/p>\n

\u4e0d\u53ef\u53d8\u6027<\/strong><\/p>\n

\u4e0d\u53ef\u53d8\u6027\u610f\u5473\u7740\u5bf9\u8c61\u4e00\u65e6\u521b\u5efa\uff0c\u5c31\u4e0d\u518d\u5141\u8bb8\u5bf9\u5176\u8fdb\u884c\u66f4\u6539\u3002\u8fd9\u6d88\u9664\u4e86\u5bf9\u5e76\u53d1\u63a7\u5236\u7684\u9700\u8981\uff0c\u56e0\u4e3a\u591a\u4e2a\u7ebf\u7a0b\u53ef\u4ee5\u5b89\u5168\u5730\u8bfb\u53d6\u548c\u5904\u7406\u76f8\u540c\u7684\u6570\u636e\u3002<\/p>\n

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

\/\/ \u53ef\u53d8 List\nList<Integer> mutableList = new ArrayList<>();\n\n\/\/ \u4e0d\u53ef\u53d8 List\nList<Integer> immutableList = List.of(1, 2, 3);\n\n\/\/ \u5c1d\u8bd5\u4fee\u6539\u4e0d\u53ef\u53d8\u5217\u8868\u4f1a\u5bfc\u81f4\u5f02\u5e38\nimmutableList.add(4);<\/pre>\n
\u9ad8\u9636\u51fd\u6570<\/strong><\/p>\n
\u9ad8\u9636\u51fd\u6570\u662f\u63a5\u53d7\u51fd\u6570\u4f5c\u4e3a\u53c2\u6570\u6216\u8fd4\u56de\u503c\u7684\u51fd\u6570\u3002\u5b83\u4eec\u5141\u8bb8\u6211\u4eec\u5bf9\u6570\u636e\u8fdb\u884c\u66f4\u9ad8\u7ea7\u522b\u7684\u62bd\u8c61\uff0c\u4ece\u800c\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u3002<\/p>\n
\u4ee3\u7801\u793a\u4f8b\uff1a<\/strong><\/p>\n
\/\/ \u9ad8\u9636\u51fd\u6570\uff0c\u63a5\u53d7\u51fd\u6570\u4f5c\u4e3a\u53c2\u6570\nFunction<Integer, Integer> add = n -> n + 1;\n\n\/\/ \u5c06\u9ad8\u9636\u51fd\u6570\u5e94\u7528\u4e8e\u96c6\u5408\nList<Integer> numbers = List.of(1, 2, 3);\nList<Integer> incrementedNumbers = numbers.stream()\n    .map(add)\n    .toList();<\/pre>\n
\u5b9e\u6218\u6848\u4f8b<\/strong><\/p>\n
\u4ee5\u4e0b\u662f\u4e00\u4e2a\u4f7f\u7528 Java \u51fd\u6570\u5f0f\u7f16\u7a0b\u8fdb\u884c\u6570\u636e\u5904\u7406\u7684\u5b9e\u6218\u6848\u4f8b\uff1a<\/p>\n
\u573a\u666f\uff1a<\/strong>\u6709\u4e00\u4e2a\u5305\u542b\u5927\u91cf\u9500\u552e\u8bb0\u5f55\u7684\u6570\u636e\u96c6\uff0c\u9700\u8981\u6309\u65e5\u671f\u805a\u5408\u9500\u552e\u603b\u989d\u3002<\/p>\n
\u4f20\u7edf\u65b9\u6cd5\uff1a<\/strong><\/p>\n
Map<LocalDate, Double> salesByDate = new HashMap<>();\n\n\/\/ \u904d\u5386\u8bb0\u5f55\u5e76\u66f4\u65b0\u6620\u5c04\nfor (SalesRecord record : records) {\n    LocalDate date = record.getDate();\n    double saleAmount = record.getSaleAmount();\n\n    salesByDate.put(date, salesByDate.getOrDefault(date, 0.0) + saleAmount);\n}<\/pre>\n
\u51fd\u6570\u5f0f\u65b9\u6cd5\uff1a<\/strong><\/p>\n
Map<LocalDate, Double> salesByDate = records.stream()\n    .collect(Collectors.groupingBy(\n        SalesRecord::getDate, \n        Collectors.summingDouble(SalesRecord::getSaleAmount)));<\/pre>\n
\u51fd\u6570\u5f0f\u65b9\u6cd5\u6d88\u9664\u4e86\u5bf9\u663e\u5f0f\u904d\u5386\u8bb0\u5f55\u7684\u9700\u6c42\uff0c\u800c\u662f\u4f7f\u7528\u6d41 API \u5bf9\u6570\u636e\u96c6\u8fdb\u884c\u5e76\u884c\u5904\u7406\u3002\u8fd9\u663e\u8457\u63d0\u9ad8\u4e86\u6027\u80fd\uff0c\u5c24\u5176\u662f\u5728\u5904\u7406\u5927\u6570\u636e\u96c6\u65f6\u3002<\/p>\n
\u7ed3\u8bba<\/strong><\/p>\n
\u5728\u6570\u636e\u5904\u7406\u4e2d\uff0cJava \u51fd\u6570\u5f0f\u7f16\u7a0b\u901a\u8fc7\u5229\u7528\u4e0d\u53ef\u53d8\u6027\u548c\u9ad8\u9636\u51fd\u6570\uff0c\u53ef\u4ee5\u63d0\u4f9b\u663e\u8457\u7684\u6027\u80fd\u63d0\u5347\u3002\u5b83\u5141\u8bb8\u5bf9\u4ee3\u7801\u8fdb\u884c\u66f4\u9ad8\u7ea7\u522b\u7684\u62bd\u8c61\uff0c\u4ece\u800c\u63d0\u9ad8\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u3002\u5bf9\u4e8e\u9700\u8981\u5904\u7406\u5927\u6570\u636e\u96c6\u7684\u5e94\u7528\u7a0b\u5e8f\uff0c\u51fd\u6570\u5f0f\u7f16\u7a0b\u662f\u4e00\u4e2a\u5f3a\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u4f18\u5316\u6027\u80fd\u548c\u4ee3\u7801\u8d28\u91cf\u3002<\/p>\n
\u5230\u8fd9\u91cc\uff0c\u6211\u4eec\u4e5f\u5c31\u8bb2\u5b8c\u4e86\u300aJava\u51fd\u6570\u5f0f\u7f16\u7a0b\u5728\u6570\u636e\u5904\u7406\u4e2d\u5982\u4f55\u63d0\u9ad8\u6027\u80fd\uff1f\u300b\u7684\u5185\u5bb9\u4e86\u3002\u4e2a\u4eba\u8ba4\u4e3a\uff0c\u57fa\u7840\u77e5\u8bc6\u7684\u5b66\u4e60\u548c\u5de9\u56fa\uff0c\u662f\u4e3a\u4e86\u66f4\u597d\u7684\u5c06\u5176\u8fd0\u7528\u5230\u9879\u76ee\u4e2d\uff0c\u6b22\u8fce\u5173\u6ce8\u516c\u4f17\u53f7\uff0c\u5e26\u4f60\u4e86\u89e3\u66f4\u591a\u5173\u4e8ejava,\u51fd\u6570\u5f0f\u7f16\u7a0b\u7684\u77e5\u8bc6\u70b9\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u5728\u6570\u636e\u5904\u7406\u4e2d\u5982...<\/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-202707","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202707","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=202707"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202707\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=202707"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=202707"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=202707"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}