{"id":202961,"date":"2025-05-22T09:47:00","date_gmt":"2025-05-22T01:47:00","guid":{"rendered":"https:\/\/server.hk\/cnblog\/202961\/"},"modified":"2025-05-22T09:47:00","modified_gmt":"2025-05-22T01:47:00","slug":"java%e5%87%bd%e6%95%b0%e5%bc%8f%e7%bc%96%e7%a8%8b%e5%b9%b6%e8%a1%8c%e6%89%81%e5%b9%b3%e5%8c%96%e6%93%8d%e4%bd%9c","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/202961\/","title":{"rendered":"Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u5e76\u884c\u6241\u5e73\u5316\u64cd\u4f5c"},"content":{"rendered":"

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

Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u5e76\u884c\u6241\u5e73\u5316\u64cd\u4f5c<\/h1>\n

\u73cd\u60dc\u65f6\u95f4\uff0c\u52e4\u594b\u5b66\u4e60\uff01\u4eca\u5929\u7ed9\u5927\u5bb6\u5e26\u6765\u300aJava\u51fd\u6570\u5f0f\u7f16\u7a0b\u5e76\u884c\u6241\u5e73\u5316\u64cd\u4f5c\u300b<\/span>\uff0c\u6b63\u6587\u5185\u5bb9\u4e3b\u8981\u6d89\u53ca\u5230<\/span>\u7b49\u7b49\uff0c\u5982\u679c\u4f60\u6b63\u5728\u5b66\u4e60\u6587\u7ae0<\/span>\uff0c\u6216\u8005\u662f\u5bf9\u6587\u7ae0<\/span>\u6709\u7591\u95ee\uff0c\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u6211\uff01\u540e\u9762\u6211\u4f1a\u6301\u7eed\u66f4\u65b0\u76f8\u5173\u5185\u5bb9\u7684\uff0c\u5e0c\u671b\u90fd\u80fd\u5e2e\u5230\u6b63\u5728\u5b66\u4e60\u7684\u5927\u5bb6\uff01<\/p>\n

Java \u51fd\u6570\u5f0f\u7f16\u7a0b\u63d0\u4f9b\u4e86\u5e76\u884c\u6241\u5e73\u5316\u64cd\u4f5c\uff0c\u4f7f\u7528 flatMapToInt() \u548c flatMapToDouble() \u65b9\u6cd5\u53ef\u4ee5\u5c06\u5d4c\u5957\u6570\u636e\u7ed3\u6784\u5c55\u5f00\u6210\u5355\u4e2a\u5217\u8868\uff0c\u5e76\u884c\u6267\u884c\u4ee5\u63d0\u9ad8\u6027\u80fd\uff0c\u5229\u7528\u4e86 Fork\/Join \u7b49\u5e95\u5c42\u5e76\u884c\u6846\u67b6\uff0c\u5728\u591a\u6838\u7cfb\u7edf\u4e0a\u66f4\u9ad8\u6548\u3002<\/p>\n

<\/p>\n

Java \u51fd\u6570\u5f0f\u7f16\u7a0b\uff1a\u5e76\u884c\u6241\u5e73\u5316\u64cd\u4f5c<\/h2>\n

\u4ecb\u7ecd<\/strong><\/p>\n

\u6241\u5e73\u5316\u64cd\u4f5c\u7528\u4e8e\u5c06\u5d4c\u5957\u6570\u636e\u7ed3\u6784\u5c55\u5f00\u6210\u5355\u4e2a\u5217\u8868\u3002\u5728 Java \u4e2d\uff0c\u53ef\u4ee5\u5e76\u884c\u5316\u6b64\u64cd\u4f5c\u4ee5\u63d0\u9ad8\u6027\u80fd\u3002\u672c\u6587\u5c06\u5c55\u793a\u5982\u4f55\u4f7f\u7528 Java \u4e2d\u7684 Stream API \u5b9e\u73b0\u5e76\u884c\u6241\u5e73\u5316\u64cd\u4f5c\u3002<\/p>\n

\u8bed\u6cd5<\/strong><\/p>\n

flatMapToInt()<\/code> \u548c flatMapToDouble()<\/code> \u65b9\u6cd5\u662f\u5e76\u884c\u6241\u5e73\u5316\u7684 Stream API \u65b9\u6cd5\u3002\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n

IntStream flatMapToInt(IntFunction<? super T, ? extends IntStream>)\nDoubleStream flatMapToDouble(DoubleFunction<? super T, ? extends DoubleStream>)<\/pre>\n
\u5b9e\u6218\u6848\u4f8b<\/strong><\/p>\n
\u8003\u8651\u4ee5\u4e0b\u5d4c\u5957\u5217\u8868\uff1a<\/p>\n
List<List<Integer>> nestedList = List.of(\n    List.of(1, 2),\n    List.of(3, 4),\n    List.of(5, 6)\n);<\/pre>\n
\u4f7f\u7528\u5e76\u884c\u6241\u5e73\u5316<\/strong><\/p>\n
\u4e3a\u4e86\u5e76\u884c\u6241\u5e73\u5316\u6b64\u5217\u8868\uff0c\u53ef\u4ee5\u4f7f\u7528 flatMapToInt()<\/code> \u65b9\u6cd5\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n
int[] flattenedArray = nestedList.stream()\n    .flatMapToInt(list -> list.stream().mapToInt(Integer::intValue).toArray())\n    .toArray();<\/pre>\n
\u6b64\u4ee3\u7801\u5c06\u5c55\u5f00\u5d4c\u5957\u5217\u8868\uff0c\u5e76\u5c06\u6240\u6709\u6574\u6570\u6536\u96c6\u5230\u4e00\u4e2a\u4e00\u7ef4\u6570\u7ec4\u4e2d\u3002<\/p>\n
\u5e76\u884c\u6027<\/strong><\/p>\n
flatMapToInt()<\/code> \u65b9\u6cd5\u5e76\u884c\u6267\u884c\uff0c\u5229\u7528\u5e95\u5c42\u5e76\u884c\u6846\u67b6\uff08\u4f8b\u5982 Fork\/Join\uff09\u3002\u8fd9\u4f7f\u5f97\u6241\u5e73\u5316\u64cd\u4f5c\u5728\u591a\u6838\u7cfb\u7edf\u4e0a\u66f4\u9ad8\u6548\u3002<\/p>\n
\u7ed3\u8bba<\/strong><\/p>\n
\u901a\u8fc7\u4f7f\u7528 Java \u4e2d\u7684 flatMapToInt()<\/code> \u65b9\u6cd5\uff0c\u6211\u4eec\u53ef\u4ee5\u5e76\u884c\u6241\u5e73\u5316\u5d4c\u5957\u6570\u636e\u7ed3\u6784\uff0c\u4ece\u800c\u63d0\u9ad8\u6027\u80fd\u3002\u8fd9\u5728\u5904\u7406\u5927\u578b\u6570\u636e\u96c6\u65f6\u7279\u522b\u6709\u7528\uff0c\u56e0\u4e3a\u5b83\u53ef\u4ee5\u5145\u5206\u5229\u7528\u591a\u6838\u5904\u7406\u5668\u7684\u4f18\u52bf\u3002<\/p>\n
\u4ee5\u4e0a\u5c31\u662f\u300aJava\u51fd\u6570\u5f0f\u7f16\u7a0b\u5e76\u884c\u6241\u5e73\u5316\u64cd\u4f5c\u300b\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u5173\u4e8e\u51fd\u6570\u5f0f\u7f16\u7a0b,\u5e76\u884c\u7684\u8d44\u6599\u8bf7\u5173\u6ce8\u516c\u4f17\u53f7\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u5e76\u884c\u6241\u5e73\u5316\u64cd\u4f5c...<\/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-202961","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202961","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=202961"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202961\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=202961"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=202961"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=202961"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}