{"id":202899,"date":"2025-05-22T08:58:23","date_gmt":"2025-05-22T00:58:23","guid":{"rendered":"https:\/\/server.hk\/cnblog\/202899\/"},"modified":"2025-05-22T08:58:23","modified_gmt":"2025-05-22T00:58:23","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%e4%bb%a3%e7%a0%81%e7%9a%84%e5%8f%af%e7%bb%b4%e6%8a%a4","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/202899\/","title":{"rendered":"Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u5728\u6570\u636e\u5904\u7406\u4e2d\u5982\u4f55\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u7ef4\u62a4\u6027\uff1f"},"content":{"rendered":"

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

Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u5728\u6570\u636e\u5904\u7406\u4e2d\u5982\u4f55\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u7ef4\u62a4\u6027\uff1f<\/h1>\n

\u5b66\u4e60\u6587\u7ae0<\/span>\u8981\u52aa\u529b\uff0c\u4f46\u662f\u4e0d\u8981\u6025\uff01\u4eca\u5929\u7684\u8fd9\u7bc7\u6587\u7ae0\u300aJava\u51fd\u6570\u5f0f\u7f16\u7a0b\u5728\u6570\u636e\u5904\u7406\u4e2d\u5982\u4f55\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u7ef4\u62a4\u6027\uff1f\u300b<\/span>\u5c06\u4f1a\u4ecb\u7ecd\u5230<\/span>\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u4f60\u60f3\u6df1\u5165\u5b66\u4e60\u6587\u7ae0<\/span>\uff0c\u53ef\u4ee5\u5173\u6ce8\u6211\uff01\u6211\u4f1a\u6301\u7eed\u66f4\u65b0\u76f8\u5173\u6587\u7ae0\u7684\uff0c\u5e0c\u671b\u5bf9\u5927\u5bb6\u90fd\u80fd\u6709\u6240\u5e2e\u52a9\uff01<\/p>\n

\u51fd\u6570\u5f0f\u7f16\u7a0b\u5728Java\u4e2d\u901a\u8fc7lambda\u8868\u8fbe\u5f0f\u548cstream API\u5b9e\u73b0\uff0c\u63d0\u5347\u4ee3\u7801\u53ef\u7ef4\u62a4\u6027\uff1a\u4e0d\u53ef\u53d8\u6570\u636e\uff1a\u5bf9\u8c61\u4e00\u65e6\u521b\u5efa\uff0c\u4e0d\u53ef\u4fee\u6539\uff0c\u786e\u4fdd\u53d8\u91cf\u6709\u6548\u6027\u3002\u7eaf\u51fd\u6570\uff1a\u4e0d\u4f9d\u8d56\u5916\u90e8\u72b6\u6001\uff0c\u4ec5\u6839\u636e\u8f93\u5165\u8ba1\u7b97\u8f93\u51fa\uff0c\u6613\u4e8e\u6d4b\u8bd5\u548c\u7406\u89e3\u3002\u61d2\u60f0\u6c42\u503c\uff1a\u53ea\u5728\u9700\u8981\u65f6\u8ba1\u7b97\u8868\u8fbe\u5f0f\uff0c\u63d0\u5347\u6027\u80fd\u5e76\u51cf\u5c11\u5185\u5b58\u6d88\u8017\u3002\u5b9e\u6218\u6848\u4f8b\u4e2d\uff0c\u8fd0\u7528\u51fd\u6570\u5f0f\u7f16\u7a0b\u63d0\u53d6\u5b66\u751f\u59d3\u540d\u548c\u6210\u7ee9\u5230\u6620\u5c04\u4e2d\uff0c\u7b80\u6d01\u53ef\u7ef4\u62a4\u3002<\/p>\n

<\/p>\n

Java\u51fd\u6570\u5f0f\u7f16\u7a0b\uff1a\u63d0\u5347\u6570\u636e\u5904\u7406\u4ee3\u7801\u53ef\u7ef4\u62a4\u6027<\/strong><\/p>\n

\u51fd\u6570\u5f0f\u7f16\u7a0b\u662f\u4e00\u79cd\u7f16\u7a0b\u8303\u5f0f\uff0c\u5b83\u5f3a\u8c03\u4f7f\u7528\u4e0d\u53ef\u53d8\u6570\u636e\u3001\u7eaf\u51fd\u6570\u548c\u61d2\u60f0\u6c42\u503c\u3002\u5728Java\u4e2d\uff0c\u51fd\u6570\u5f0f\u7f16\u7a0b\u529f\u80fd\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528lambda\u8868\u8fbe\u5f0f\u548cstream API\u6765\u5b9e\u73b0\u3002<\/p>\n

\u4e0d\u53ef\u53d8\u6570\u636e<\/strong><\/p>\n

\u4e0d\u53ef\u53d8\u6570\u636e\u610f\u5473\u7740\u4e00\u65e6\u521b\u5efa\uff0c\u5c31\u4e0d\u80fd\u518d\u4fee\u6539\u3002\u8fd9\u53ef\u4ee5\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u7ef4\u62a4\u6027\uff0c\u56e0\u4e3a\u6211\u4eec\u53ef\u4ee5\u786e\u4fe1\u53d8\u91cf\u5728\u6211\u4eec\u7684\u4ee3\u7801\u7684\u6574\u4e2a\u751f\u547d\u5468\u671f\u4e2d\u90fd\u662f\u6709\u6548\u7684\u3002\u4f8b\u5982\uff1a<\/p>\n

List<Integer> numbers = List.of(1, 2, 3);\n\/\/ ... some code\nSystem.out.println(numbers); \/\/ \u8f93\u51fa\uff1a[1, 2, 3]<\/pre>\n
\u7eaf\u51fd\u6570<\/strong><\/p>\n
\u7eaf\u51fd\u6570\u4e0d\u4f9d\u8d56\u4e8e\u5916\u90e8\u72b6\u6001\u6216\u53d8\u91cf\u3002\u5b83\u4eec\u53ea\u6839\u636e\u8f93\u5165\u53c2\u6570\u8ba1\u7b97\u8f93\u51fa\u3002\u7eaf\u51fd\u6570\u6613\u4e8e\u6d4b\u8bd5\u548c\u7406\u89e3\uff0c\u56e0\u4e3a\u5b83\u53ef\u4ee5\u8ba9\u6211\u4eec\u7684\u4ee3\u7801\u66f4\u5177\u53ef\u9884\u6d4b\u6027\u3002\u4f8b\u5982\uff1a<\/p>\n
public static int sum(List<Integer> numbers) {\n    return numbers.stream().reduce(0, Integer::sum);\n}<\/pre>\n
\u61d2\u60f0\u6c42\u503c<\/strong><\/p>\n
\u61d2\u60f0\u6c42\u503c\u610f\u5473\u7740\u53ea\u5728\u9700\u8981\u65f6\u624d\u6c42\u503c\u8868\u8fbe\u5f0f\u3002\u8fd9\u53ef\u4ee5\u63d0\u9ad8\u6027\u80fd\u5e76\u51cf\u5c11\u5185\u5b58\u6d88\u8017\u3002\u4f8b\u5982\uff1a<\/p>\n
List<Integer> filteredNumbers = numbers.stream()\n                                    .filter(n -> n % 2 == 0);\n\/\/ ... some code\nSystem.out.println(filteredNumbers); \/\/ \u53ea\u5728\u9700\u8981\u65f6\u624d\u4f1a\u8ba1\u7b97\u8fc7\u6ee4\u540e\u7684\u6570\u5b57<\/pre>\n
\u5b9e\u6218\u6848\u4f8b\uff1a\u6570\u636e\u63d0\u53d6<\/strong><\/p>\n
\u8ba9\u6211\u4eec\u770b\u4e00\u4e0b\u4e00\u4e2a\u5b9e\u6218\u6848\u4f8b\uff0c\u770b\u770b\u5982\u4f55\u4f7f\u7528Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u6765\u63d0\u9ad8\u6570\u636e\u63d0\u53d6\u4ee3\u7801\u7684\u53ef\u7ef4\u62a4\u6027\u3002<\/p>\n
\u5047\u8bbe\u6211\u4eec\u6709\u4e00\u4e2a\u5305\u542b\u5b66\u751f\u6570\u636e\u7684\u5217\u8868\uff0c\u6211\u4eec\u5e0c\u671b\u5c06\u5b66\u751f\u7684\u59d3\u540d\u548c\u6210\u7ee9\u63d0\u53d6\u5230\u4e00\u4e2a\u6620\u5c04\u4e2d\u3002<\/p>\n
\u4f7f\u7528\u4f20\u7edf\u65b9\u6cd5\uff0c\u6211\u4eec\u5c06\u904d\u5386\u5217\u8868\u5e76 manually \u521b\u5efa\u6620\u5c04\u6761\u76ee\uff1a<\/p>\n
Map<String, Integer> studentGrades = new HashMap<>();\nfor (Student student : students) {\n    studentGrades.put(student.getName(), student.getGrade());\n}<\/pre>\n
\u4f7f\u7528\u51fd\u6570\u5f0f\u7f16\u7a0b\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528stream API\u548ccollect\u64cd\u4f5c\u6765\u7b80\u5316\u6b64\u8fc7\u7a0b\uff1a<\/p>\n
Map<String, Integer> studentGrades = students.stream()\n                                           .collect(Collectors.toMap(\n                                                   Student::getName,\n                                                   Student::getGrade\n                                           ));<\/pre>\n
\u8fd9\u79cd\u51fd\u6570\u5f0f\u65b9\u6cd5\u65e2\u7b80\u6d01\u53c8\u53ef\u7ef4\u62a4\uff0c\u56e0\u4e3a\u5b83\u5229\u7528\u4e86\u4e0d\u53ef\u53d8\u6570\u636e\u3001\u7eaf\u51fd\u6570\u548c\u61d2\u60f0\u6c42\u503c\u7b49\u51fd\u6570\u5f0f\u7f16\u7a0b\u539f\u5219\u3002<\/p>\n
\u4eca\u5929\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u5e0c\u671b\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff1b\u5173\u4e8e\u6587\u7ae0\u7684\u6280\u672f\u77e5\u8bc6\u6211\u4eec\u4f1a\u4e00\u70b9\u70b9\u6df1\u5165\u4ecb\u7ecd\uff0c\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u516c\u4f17\u53f7\uff0c\u4e00\u8d77\u5b66\u4e60\u7f16\u7a0b~<\/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-202899","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202899","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=202899"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202899\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=202899"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=202899"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=202899"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}