{"id":202897,"date":"2025-05-22T08:03:02","date_gmt":"2025-05-22T00:03:02","guid":{"rendered":"https:\/\/server.hk\/cnblog\/202897\/"},"modified":"2025-05-22T08:03:02","modified_gmt":"2025-05-22T00:03:02","slug":"java%e5%87%bd%e6%95%b0%e5%bc%8f%e7%bc%96%e7%a8%8b%e4%b8%ad%e7%9a%84%e9%94%99%e8%af%af%e5%a4%84%e7%90%86%e5%92%8c%e5%bc%82%e5%b8%b8%e5%a4%84%e7%90%86%e6%9c%ba%e5%88%b6","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/202897\/","title":{"rendered":"Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u4e2d\u7684\u9519\u8bef\u5904\u7406\u548c\u5f02\u5e38\u5904\u7406\u673a\u5236"},"content":{"rendered":"

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

Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u4e2d\u7684\u9519\u8bef\u5904\u7406\u548c\u5f02\u5e38\u5904\u7406\u673a\u5236<\/h1>\n

\u5404\u4f4d\u5c0f\u4f19\u4f34\u4eec\uff0c\u5927\u5bb6\u597d\u5440\uff01\u770b\u770b\u4eca\u5929\u6211\u53c8\u7ed9\u5404\u4f4d\u5e26\u6765\u4e86\u4ec0\u4e48\u6587\u7ae0\uff1f\u672c\u6587\u6807\u9898\u662f<\/span>\u300aJava\u51fd\u6570\u5f0f\u7f16\u7a0b\u4e2d\u7684\u9519\u8bef\u5904\u7406\u548c\u5f02\u5e38\u5904\u7406\u673a\u5236\u300b<\/span>\uff0c\u5f88\u660e\u663e\u662f\u5173\u4e8e\u6587\u7ae0<\/span>\u7684\u6587\u7ae0\u54c8\u54c8\u54c8\uff0c\u5176\u4e2d\u5185\u5bb9\u4e3b\u8981\u4f1a\u6d89\u53ca\u5230<\/span>\u7b49\u7b49\uff0c\u5982\u679c\u80fd\u5e2e\u5230\u4f60\uff0c\u89c9\u5f97\u5f88\u4e0d\u9519\u7684\u8bdd\uff0c\u6b22\u8fce\u5404\u4f4d\u591a\u591a\u70b9\u8bc4\u548c\u5206\u4eab\uff01<\/span><\/p>\n

<\/p>\n

Java \u51fd\u6570\u5f0f\u7f16\u7a0b\u4e2d\u7684\u9519\u8bef\u5904\u7406\u548c\u5f02\u5e38\u5904\u7406\u673a\u5236<\/strong><\/p>\n

\u5728\u51fd\u6570\u5f0f\u7f16\u7a0b\u4e2d\uff0c\u9519\u8bef\u5904\u7406\u548c\u5f02\u5e38\u5904\u7406\u81f3\u5173\u91cd\u8981\uff0c\u5b83\u4eec\u4e3a\u5904\u7406\u610f\u5916\u60c5\u51b5\u548c\u786e\u4fdd\u7a0b\u5e8f\u5065\u58ee\u6027\u63d0\u4f9b\u4e86\u673a\u5236\u3002<\/p>\n

\u9519\u8bef\u5904\u7406<\/strong><\/p>\n

\u5728 Java \u4e2d\uff0c\u4f7f\u7528 Optional<\/code> \u7c7b\u6765\u5904\u7406\u53ef\u80fd\u4e0d\u5b58\u5728\u7684\u503c\u3002Optional<\/code> \u662f\u4e00\u79cd\u5305\u88c5\u5668\u7c7b\u578b\uff0c\u5b83\u53ef\u4ee5\u5305\u542b\u4e00\u4e2a\u503c\u6216\u4ec0\u4e48\u90fd\u4e0d\u5305\u542b\uff08\u79f0\u4e3a empty<\/code>\uff09\u3002<\/p>\n

\/\/ \u5b9a\u4e49\u4e00\u4e2a\u53ef\u80fd\u4e3a null \u7684\u503c\nString value = null;\n\n\/\/ \u4f7f\u7528 Optional \u5305\u88c5\u503c\nOptional<String> optionalValue = Optional.ofNullable(value);\n\n\/\/ \u68c0\u67e5\u503c\u662f\u5426\u5b58\u5728\nif (optionalValue.isPresent()) {\n    \/\/ \u83b7\u53d6\u503c\n    String nonNullValue = optionalValue.get();\n} else {\n    \/\/ \u5904\u7406\u7a7a\u503c\u7684\u60c5\u51b5\n}<\/pre>\n
\u5f02\u5e38\u5904\u7406<\/strong><\/p>\n
Java \u4e2d\u7684\u5f02\u5e38\u673a\u5236\u4f7f\u7528 try-catch<\/code> \u5757\u6765\u5904\u7406\u5f02\u5e38\u60c5\u51b5\u3002<\/p>\n
try {\n    \/\/ \u53ef\u80fd\u4f1a\u629b\u51fa\u5f02\u5e38\u7684\u4ee3\u7801\n} catch (Exception e) {\n    \/\/ \u5904\u7406\u5f02\u5e38\n} finally {\n    \/\/ \u65e0\u8bba\u662f\u5426\u53d1\u751f\u5f02\u5e38\u90fd\u4f1a\u6267\u884c\u7684\u4ee3\u7801\n}<\/pre>\n
\u5b9e\u6218\u6848\u4f8b<\/strong><\/p>\n
\u83b7\u53d6\u6587\u4ef6\u5185\u5bb9<\/strong><\/p>\n
try {\n    \/\/ \u8bfb\u53d6\u6587\u4ef6\n    String content = Files.readString(Paths.get(\"file.txt\"));\n} catch (IOException e) {\n    \/\/ \u5904\u7406\u8bfb\u53d6\u6587\u4ef6\u5931\u8d25\u7684\u60c5\u51b5\n}<\/pre>\n
\u89e3\u6790 JSON<\/strong><\/p>\n
try {\n    \/\/ \u89e3\u6790 JSON\n    JsonObject jsonObject = new JsonParser().parse(jsonString).getAsJsonObject();\n} catch (JsonSyntaxException e) {\n    \/\/ \u5904\u7406 JSON \u8bed\u6cd5\u9519\u8bef\u7684\u60c5\u51b5\n}<\/pre>\n
\u901a\u8fc7\u4f7f\u7528 Optional<\/code> \u548c try-catch<\/code> \u5757\uff0c\u53ef\u4ee5\u5728\u51fd\u6570\u5f0f\u7f16\u7a0b\u4e2d\u4f18\u96c5\u5730\u5904\u7406\u9519\u8bef\u548c\u5f02\u5e38\uff0c\u4ece\u800c\u63d0\u9ad8\u7a0b\u5e8f\u7684\u5065\u58ee\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u3002<\/p>\n
\u7ec8\u4e8e\u4ecb\u7ecd\u5b8c\u5566\uff01\u5c0f\u4f19\u4f34\u4eec\uff0c\u8fd9\u7bc7\u5173\u4e8e\u300aJava\u51fd\u6570\u5f0f\u7f16\u7a0b\u4e2d\u7684\u9519\u8bef\u5904\u7406\u548c\u5f02\u5e38\u5904\u7406\u673a\u5236\u300b\u7684\u4ecb\u7ecd\u5e94\u8be5\u8ba9\u4f60\u6536\u83b7\u591a\u591a\u4e86\u5427\uff01\u6b22\u8fce\u5927\u5bb6\u6536\u85cf\u6216\u5206\u4eab\u7ed9\u66f4\u591a\u9700\u8981\u5b66\u4e60\u7684\u670b\u53cb\u5427~\u516c\u4f17\u53f7\u4e5f\u4f1a\u53d1\u5e03\u6587\u7ae0\u76f8\u5173\u77e5\u8bc6\uff0c\u5feb\u6765\u5173\u6ce8\u5427\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
Java\u51fd\u6570\u5f0f\u7f16\u7a0b\u4e2d\u7684\u9519\u8bef\u5904\u7406\u548c...<\/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-202897","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202897","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=202897"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/202897\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=202897"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=202897"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=202897"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}