{"id":202794,"date":"2025-05-22T11:04:12","date_gmt":"2025-05-22T03:04:12","guid":{"rendered":"https:\/\/server.hk\/cnblog\/202794\/"},"modified":"2025-05-22T11:04:12","modified_gmt":"2025-05-22T03:04:12","slug":"java%e5%87%bd%e6%95%b0%e5%bc%8f%e7%bc%96%e7%a8%8b%e7%9a%84%e6%9c%80%e4%bd%b3%e5%ae%9e%e8%b7%b5","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/202794\/","title":{"rendered":"Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u7684\u6700\u4f73\u5b9e\u8df5"},"content":{"rendered":"

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

Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u7684\u6700\u4f73\u5b9e\u8df5<\/h1>\n

\u6587\u7ae0\u5c0f\u767d\u4e00\u679a\uff0c\u6b63\u5728\u4e0d\u65ad\u5b66\u4e60\u79ef\u7d2f\u77e5\u8bc6\uff0c\u73b0\u5c06\u5b66\u4e60\u5230\u7684\u77e5\u8bc6\u8bb0\u5f55\u4e00\u4e0b\uff0c\u4e5f\u662f\u5c06\u6211\u7684\u6240\u5f97\u5206\u4eab\u7ed9\u5927\u5bb6\uff01\u800c\u4eca\u5929\u8fd9\u7bc7\u6587\u7ae0\u300aJava\u51fd\u6570\u5f0f\u7f16\u7a0b\u7684\u6700\u4f73\u5b9e\u8df5\u300b\u5e26\u5927\u5bb6\u6765\u4e86\u89e3\u4e00\u4e0b##content_title##\uff0c\u5e0c\u671b\u5bf9\u5927\u5bb6\u7684\u77e5\u8bc6\u79ef\u7d2f\u6709\u6240\u5e2e\u52a9\uff0c\u4ece\u800c\u5f25\u8865\u81ea\u5df1\u7684\u4e0d\u8db3\uff0c\u52a9\u529b\u5b9e\u6218\u5f00\u53d1\uff01<\/p>\n

<\/p>\n

Java \u51fd\u6570\u5f0f\u7f16\u7a0b\u6700\u4f73\u5b9e\u8df5\u5305\u62ec\uff1a\u4e0d\u53ef\u53d8\u6027\uff1a \u6807\u8bb0\u5b57\u6bb5\u548c\u7c7b\u4e3a final \u4ee5\u786e\u4fdd\u4e0d\u53ef\u53d8\u3002\u7eaf\u51fd\u6570\uff1a \u4ec5\u4f9d\u8d56\u8f93\u5165\u4e14\u4e0d\u4ea7\u751f\u526f\u4f5c\u7528\uff0c\u4fbf\u4e8e\u6d4b\u8bd5\u548c\u5e76\u884c\u5316\u3002Lambda \u8868\u8fbe\u5f0f\uff1a \u7b80\u5316\u4ee3\u7801\u5e76\u63d0\u9ad8\u53ef\u8bfb\u6027\uff0c\u7528\u4f5c\u51fd\u6570\u503c\u3002\u51fd\u6570\u5f0f\u63a5\u53e3\uff1a \u521b\u5efa Lambda \u8868\u8fbe\u5f0f\u800c\u65e0\u9700\u5b9e\u73b0\u6574\u4e2a\u63a5\u53e3\u3002\u5904\u7406\u526f\u4f5c\u7528\uff1a \u4f7f\u7528 Optional\u3001CheckedExceptions \u548c ThreadLocal \u6280\u5de7\u6765\u7ba1\u7406\u526f\u4f5c\u7528\u3002<\/p>\n

<\/p>\n

Java \u51fd\u6570\u5f0f\u7f16\u7a0b\u6700\u4f73\u5b9e\u8df5<\/strong><\/p>\n

\u51fd\u6570\u5f0f\u7f16\u7a0b (FP) \u662f\u4e00\u79cd\u7a0b\u5e8f\u8bbe\u8ba1\u8303\u5f0f\uff0c\u5f3a\u8c03\u4e0d\u53ef\u53d8\u72b6\u6001\u548c\u51fd\u6570\u4f5c\u4e3a\u4e00\u7c7b\u503c\u3002Java 8 \u5f15\u5165\u4e86 Lambda \u8868\u8fbe\u5f0f\u548c\u51fd\u6570\u5f0f\u63a5\u53e3\uff0c\u4f7f FP \u6982\u5ff5\u66f4\u5bb9\u6613\u5728\u65b0\u9879\u76ee\u548c\u9057\u7559\u4ee3\u7801\u5e93\u4e2d\u5b9e\u73b0\u3002<\/p>\n

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

FP \u7684\u6838\u5fc3\u539f\u5219\u4e4b\u4e00\u662f\u4e0d\u53ef\u53d8\u6027\u3002\u4e0d\u53ef\u53d8\u5bf9\u8c61\u4e0d\u80fd\u88ab\u4fee\u6539\uff0c\u8fd9\u6d88\u9664\u4e86\u72b6\u6001\u76f8\u5173\u7684\u9519\u8bef\u548c\u5e76\u53d1\u95ee\u9898\u3002\u5728 Java \u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528 final<\/code> \u5173\u952e\u5b57\u6807\u8bb0\u5b57\u6bb5\u548c\u7c7b\u4e0d\u53ef\u53d8\u3002<\/p>\n

public class Person {\n    private final String name;\n    private final int age;\n\n    \/\/ ...\n}<\/pre>\n
\u4f7f\u7528\u7eaf\u51fd\u6570<\/strong><\/p>\n
\u7eaf\u51fd\u6570\u53ea\u4f9d\u8d56\u4e8e\u5176\u8f93\u5165\uff0c\u4e0d\u4f1a\u4ea7\u751f\u526f\u4f5c\u7528\uff0c\u4f8b\u5982\u4fee\u6539\u5916\u90e8\u72b6\u6001\u6216\u6267\u884c I\/O \u64cd\u4f5c\u3002\u8fd9\u4f7f\u51fd\u6570\u66f4\u6613\u4e8e\u6d4b\u8bd5\uff0c\u7ef4\u62a4\u548c\u5e76\u884c\u5316\u3002<\/p>\n
public static int sum(int a, int b) {\n    return a + b;\n}<\/pre>\n
\u4f7f\u7528 Lambda \u8868\u8fbe\u5f0f<\/strong><\/p>\n
Lambda \u8868\u8fbe\u5f0f\u63d0\u4f9b\u4e86\u5c06\u51fd\u6570\u4f5c\u4e3a\u503c\u4f20\u9012\u7684\u4fbf\u6377\u65b9\u5f0f\u3002\u5b83\u4eec\u53ef\u4ee5\u7b80\u5316\u4ee3\u7801\u5e76\u63d0\u9ad8\u53ef\u8bfb\u6027\u3002<\/p>\n
List<Integer> numbers = Arrays.asList(1, 2, 3);\nint sum = numbers.stream()\n        .map(n -> n * n)\n        .reduce(0, (a, b) -> a + b);<\/pre>\n
\u5229\u7528\u51fd\u6570\u5f0f\u63a5\u53e3<\/strong><\/p>\n
\u51fd\u6570\u5f0f\u63a5\u53e3\u662f\u4e00\u7c7b\u5177\u6709\u4e00\u4e2a\u62bd\u8c61\u65b9\u6cd5\u7684\u63a5\u53e3\u3002Java 8 \u9884\u5b9a\u4e49\u4e86\u8bb8\u591a\u5e38\u89c1\u7684\u51fd\u6570\u5f0f\u63a5\u53e3\uff0c\u5982 Predicate<\/code>\u3001Function<\/code> \u548c Consumer<\/code>\u3002\u4f7f\u7528\u51fd\u6570\u5f0f\u63a5\u53e3\u53ef\u4ee5\u5728\u4e0d\u5b9e\u73b0\u6574\u4e2a\u63a5\u53e3\u7684\u60c5\u51b5\u4e0b\u521b\u5efa Lambda \u8868\u8fbe\u5f0f\u3002<\/p>\n
List<String> names = Arrays.asList(\"John\", \"Mary\", \"Bob\");\nnames.removeIf(Predicate.isEqual(\"John\"));<\/pre>\n
\u5904\u7406\u526f\u4f5c\u7528<\/strong><\/p>\n
\u867d\u7136 FP \u5f3a\u8c03\u907f\u514d\u526f\u4f5c\u7528\uff0c\u4f46\u6709\u65f6\u5b83\u4eec\u662f\u4e0d\u53ef\u907f\u514d\u7684\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u4f7f\u7528 Optional<\/code>\u3001CheckedExceptions<\/code> \u548c ThreadLocal<\/code> \u7b49\u6280\u5de7\u6765\u5904\u7406\u526f\u4f5c\u7528\u3002<\/p>\n
Optional<Integer> value = findValue();\nvalue.ifPresent(v -> processValue(v));<\/pre>\n
\u5b9e\u6218\u6848\u4f8b<\/strong><\/p>\n
\u4e8b\u4ef6\u5904\u7406<\/strong>\uff1a<\/p>\n
\u5728\u4e8b\u4ef6\u9a71\u52a8\u7684\u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0cFP \u63d0\u4f9b\u4e86\u4e00\u79cd\u5c06\u4e8b\u4ef6\u6d41\u5efa\u6a21\u4e3a\u4e0d\u53ef\u53d8\u5217\u8868\u7684\u65b9\u6cd5\uff0c\u5e76\u4ee5\u7eaf\u51fd\u6570\u5bf9\u5176\u8fdb\u884c\u64cd\u4f5c\u3002\u4f8b\u5982\uff0c\u53ef\u4ee5\u4f7f\u7528 Lambda \u4f5c\u4e3a\u4e8b\u4ef6\u4fa6\u542c\u5668\u3002<\/p>\n
EventBus eventBus = new EventBus();\neventBus.subscribe(event -> processEvent());<\/pre>\n
\u6570\u636e\u9a8c\u8bc1<\/strong>\uff1a<\/p>\n
\u901a\u8fc7\u5c06\u9a8c\u8bc1\u903b\u8f91\u5206\u89e3\u4e3a\u7eaf\u51fd\u6570\uff0cFP \u7b80\u5316\u4e86\u6570\u636e\u9a8c\u8bc1\u3002\u4f8b\u5982\uff0c\u53ef\u4ee5\u4f7f\u7528 Lambda \u8868\u8fbe\u5f0f\u9a8c\u8bc1\u8868\u5355\u8f93\u5165\u5b57\u6bb5\u3002<\/p>\n
FormValidator validator = new FormValidator();\nvalidator.validate(form)\n        .map(result -> processForm())\n        .orElse(showErrors());<\/pre>\n
\u7ed3\u8bba<\/strong>\uff1a<\/p>\n
FP \u4e3a Java \u5f00\u53d1\u4eba\u5458\u63d0\u4f9b\u4e86\u5f3a\u5927\u7684\u5de5\u5177\uff0c\u4ee5\u7f16\u5199\u66f4\u53ef\u9760\u3001\u53ef\u7ef4\u62a4\u548c\u5e76\u884c\u7684\u4ee3\u7801\u3002\u901a\u8fc7\u91c7\u7528\u4e0d\u53ef\u53d8\u6027\u3001\u7eaf\u51fd\u6570\u3001Lambda \u8868\u8fbe\u5f0f\u548c\u51fd\u6570\u5f0f\u63a5\u53e3\uff0c\u60a8\u53ef\u4ee5\u5c06 FP \u6700\u4f73\u5b9e\u8df5\u5e94\u7528\u5230\u60a8\u7684 Java \u9879\u76ee\u4e2d\u3002<\/p>\n
\u6587\u4e2d\u5173\u4e8e\u7684\u77e5\u8bc6\u4ecb\u7ecd\uff0c\u5e0c\u671b\u5bf9\u4f60\u7684\u5b66\u4e60\u6709\u6240\u5e2e\u52a9\uff01\u82e5\u662f\u53d7\u76ca\u532a\u6d45\uff0c\u90a3\u5c31\u52a8\u52a8\u9f20\u6807\u6536\u85cf\u8fd9\u7bc7\u300aJava\u51fd\u6570\u5f0f\u7f16\u7a0b\u7684\u6700\u4f73\u5b9e\u8df5\u300b\u6587\u7ae0\u5427\uff0c\u4e5f\u53ef\u5173\u6ce8\u516c\u4f17\u53f7\u4e86\u89e3\u76f8\u5173\u6280\u672f\u6587\u7ae0\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u7684\u6700\u4f73\u5b9e\u8df5 \u6587...<\/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-202794","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202794","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=202794"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202794\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=202794"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=202794"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=202794"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}