{"id":3058,"date":"2018-09-13T11:34:02","date_gmt":"2018-09-13T03:34:02","guid":{"rendered":"http:\/\/www.xttblog.com\/?p=3058"},"modified":"2018-09-13T11:34:02","modified_gmt":"2018-09-13T03:34:02","slug":"%e8%af%b7%e5%b0%86%e4%bd%a0%e7%9a%84-if-else-%e8%ae%be%e8%ae%a1%e6%88%90%e8%b4%a3%e4%bb%bb%e9%93%be%e6%a8%a1%e5%bc%8f%ef%bc%81","status":"publish","type":"post","link":"https:\/\/www.xttblog.com\/?p=3058","title":{"rendered":"\u8bf7\u5c06\u4f60\u7684 if else \u8bbe\u8ba1\u6210\u8d23\u4efb\u94fe\u6a21\u5f0f\uff01"},"content":{"rendered":"<p>\n\t\u6211\u53ea\u60f3\u95ee\u4f60\u4e00\u53e5\uff0c\u4f60\u771f\u7684\u61c2 if else \u5417\uff1f\u771f\u7684\u61c2\u8bbe\u8ba1\u6a21\u5f0f\u5417\uff1f\u771f\u7684\u662f\u9ad8\u7ea7\u5f00\u53d1\u4ea6\u6216\u662f\u67b6\u6784\u5e08\u5417\uff1f\u8bf7\u770b\u770b\u4f60\u7684\u4ee3\u7801 if else \u5df2\u8d85\u8fc7 200 \u884c\u4e86\u3002\u7c7b\u4f3c\u7684\u8fd8\u6709 switch case\uff0c\u8fd9\u6837\u7684\u8bbe\u8ba1\u548c\u505a\u6cd5\u5728\u65e5\u5e38\u4e2d\u5df2\u7ecf\u4e3e\u4e0d\u80dc\u4e3e\u3002\u6211\u6073\u8bf7\u4f60\u6dd8\u6c70\u8fd9\u6837\u7684\u505a\u6cd5\uff0c\u4e5f\u8bf7\u4f60\u5c06\u4f60\u7684 if else \u8bbe\u8ba1\u6210\u8d23\u4efb\u94fe\u6a21\u5f0f\u3002\n<\/p>\n<p>\n\t\u5f53\u7136\u5e76\u4e0d\u662f\u8981\u628a\u6240\u6709\u7684 if else(switch case \u4e5f\u7c7b\u4f3c\uff0c\u4e0b\u9762\u5c31\u53ea\u7528 if else \u505a\u8bf4\u660e)\u90fd\u6539\u6210\u8d23\u4efb\u94fe\u3002\u81f3\u4e8e\u5982\u4f55\u5224\u65ad\u662f\u4e0d\u662f\u8981\u8bbe\u8ba1\u6210\u8d23\u4efb\u94fe\u6a21\u5f0f\uff0c\u6211\u60f3\u8bf4\u6ca1\u6709\u6807\u51c6\uff0c\u5c31\u50cf\u62c6\u5206\u5fae\u670d\u52a1\u4e00\u6837\u3002\n<\/p>\n<p>\n\t\u867d\u7136\u6ca1\u6709\u6807\u51c6\uff0c\u4f46\u662f\u5e76\u4e0d\u4ee3\u8868\u6ca1\u6709\u89c4\u5219\u3002\u5982\u679c\u4f60\u7684 if else \u8bbe\u8ba1\u7684\u8fdd\u53cd\u4e86&ldquo;\u5355\u4e00\u804c\u8d23\u539f\u5219&rdquo;\u3001&ldquo;\u5f00\u95ed\u539f\u5219&rdquo;\u7b49\u90a3\u5c31\u53ef\u4ee5\u8fdb\u884c\u8d23\u4efb\u94fe\u6a21\u5f0f\u8bbe\u8ba1\u3002\n<\/p>\n<p>\n\t\u4e0b\u9762\u6211\u5217\u4e3e\u4e00\u4e2a\u4f8b\u5b50\uff0c\u6765\u8bf4\u660e\u3002\n<\/p>\n<p>\n\t\u5c31\u62ff\u6211\u4eec\u516c\u53f8\u6765\u8bf4\uff0c\u6709\u4e00\u4e2a\u91c7\u8d2d\u5ba1\u6279\u4e1a\u52a1\u3002\u4e1a\u52a1\u5904\u7406\u6d41\u7a0b\u5982\u4e0b\u56fe\uff1a\n<\/p>\n<p>\n\t<img decoding=\"async\" alt=\"\u8d23\u4efb\u94fe\u6a21\u5f0f\" src=\"https:\/\/raw.githubusercontent.com\/xmt1139057136\/xttblog\/master\/a1.gif\" style=\"width: 554px;height: 168px\" \/>\n<\/p>\n<p>\n\t\u91c7\u8d2d\u4eba\u5458\u63d0\u4ea4\u4e00\u4e2a\u5355\u5b50\u540e\uff0c\u9700\u8981\u7ecf\u8fc7\u4e3b\u4efb\u3001\u526f\u8463\u4e8b\u957f\u3001\u8463\u4e8b\u957f\u3001\u8463\u4e8b\u4f1a\u8fdb\u884c\u5ba1\u6279\u3002\u5982\u679c\u6211\u4eec\u6309\u7167 if else \u7684\u65b9\u5f0f\u7f16\u7801\uff0c\u4ee3\u7801\u5c31\u5982\u4e0b\u9762\u6240\u793a\uff1a\n<\/p>\n<pre class=\"brush:java;\">\r\n\/\/\u91c7\u8d2d\u5355\u5904\u7406\u7c7b  \r\npublic class PurchaseApprovalHandler {  \r\n    \/\/\u9012\u4ea4\u91c7\u8d2d\u5355\u7ed9\u4e3b\u4efb  \r\n    public void doApproval(PurchaseRequest request) {  \r\n        if (request.getAmount() &lt; 50000) {  \r\n            \/\/\u4e3b\u4efb\u53ef\u5ba1\u6279\u8be5\u91c7\u8d2d\u5355  \r\n            this.handleByDirector(request);  \r\n        } else if (request.getAmount() &lt; 100000) {  \r\n            \/\/\u526f\u8463\u4e8b\u957f\u53ef\u5ba1\u6279\u8be5\u91c7\u8d2d\u5355  \r\n            this.handleByVicePresident(request);  \r\n        } else if (request.getAmount() &lt; 500000) {  \r\n            \/\/\u8463\u4e8b\u957f\u53ef\u5ba1\u6279\u8be5\u91c7\u8d2d\u5355  \r\n            this.handleByPresident(request);  \r\n        } else {  \r\n            \/\/\u8463\u4e8b\u4f1a\u53ef\u5ba1\u6279\u8be5\u91c7\u8d2d\u5355  \r\n            this.handleByCongress(request);  \r\n        }  \r\n    }  \r\n      \r\n    \/\/\u4e3b\u4efb\u5ba1\u6279\u91c7\u8d2d\u5355  \r\n    public void handleByDirector(PurchaseRequest request) {  \r\n        \/\/\u4ee3\u7801\u7701\u7565  \r\n    }  \r\n      \r\n    \/\/\u526f\u8463\u4e8b\u957f\u5ba1\u6279\u91c7\u8d2d\u5355  \r\n    public void handleByVicePresident(PurchaseRequest request) {  \r\n        \/\/\u4ee3\u7801\u7701\u7565  \r\n    }  \r\n      \r\n    \/\/\u8463\u4e8b\u957f\u5ba1\u6279\u91c7\u8d2d\u5355  \r\n    public void handleByPresident(PurchaseRequest request) {  \r\n        \/\/\u4ee3\u7801\u7701\u7565  \r\n    }  \r\n      \r\n    \/\/\u8463\u4e8b\u4f1a\u5ba1\u6279\u91c7\u8d2d\u5355  \r\n    public void handleByCongress(PurchaseRequest request) {  \r\n        \/\/\u4ee3\u7801\u7701\u7565  \r\n    }  \r\n}  <\/pre>\n<p>\n\t\u770b\u4f3c\u5f88\u5b8c\u7f8e\uff0c\u4f46\u5b9e\u9645\u4e0a\u540e\u7eed\u7ef4\u62a4\u4f1a\u5b58\u5728\u5f88\u591a\u95ee\u9898\u3002\u6bd4\u5982\uff0c\u5f53\u524d\u8fd9\u4e2a\u7c7b\u4e1a\u52a1\u8fc7\u4e8e\u590d\u6742\u3002\u5404\u7ea7\u522b\u7684\u5ba1\u6279\u65b9\u6cd5\u90fd\u96c6\u4e2d\u5728\u4e00\u4e2a\u7c7b\u4e2d\uff0c\u8fdd\u53cd\u4e86&ldquo;\u5355\u4e00\u804c\u8d23\u539f\u5219&rdquo;\u3002\n<\/p>\n<p>\n\t\u529f\u80fd\u867d\u7136\u6ca1\u6709\u95ee\u9898\uff0c\u4f46\u662f\u7ef4\u62a4\u9ebb\u70e6\u3002\u4e3a\u4e86\u4e0d\u8fdd\u53cd&ldquo;\u5355\u4e00\u804c\u8d23\u539f\u5219&rdquo;\uff0c\u6211\u4eec\u4e5f\u53ef\u4ee5\u5c06\u4e1a\u52a1\u62c6\u5206\u4e3a\u591a\u4e2a\u7c7b\u3002\u4f46\u662f\u73b0\u5728\u6211\u53c8\u6709\u65b0\u7684\u9700\u6c42\u4e86\uff0c\u65b0\u589e\u4e00\u4e2a\u5ba1\u6279\u8282\u70b9\uff0c\u6216\u8005\u8c03\u6574\u67d0\u4e00\u8282\u70b9\u7684\u5ba1\u6279\u989d\u5ea6\u8303\u56f4\uff0c\u5fc5\u987b\u5bf9\u6e90\u4ee3\u7801\u8fdb\u884c\u4fee\u6539\uff0c\u540c\u65f6\u9700\u8981\u8fdb\u884c\u4e25\u683c\u7684\u6d4b\u8bd5\u3002\u73b0\u5728\u4f60\u8fd8\u89c9\u5f97\u4e0a\u9762\u7684\u8bbe\u8ba1\u65b9\u5f0f\u597d\u5417\uff1f\u662f\u4e0d\u662f\u611f\u89c9\u4e0a\u9762\u7684\u8bbe\u8ba1\u8fdd\u53cd\u4e86&ldquo;\u5f00\u95ed\u539f\u5219&rdquo;\u3002\n<\/p>\n<p>\n\t\u73b0\u5728\u6211\u544a\u8bc9\u4f60\u5e76\u6ca1\u6709\u5b8c\u7f8e\u65e0\u7f3a\u7684\u4ee3\u7801\u548c\u67b6\u6784\u8bbe\u8ba1\uff0c\u5c31\u50cf\u9ad8\u5185\u805a\u548c\u4f4e\u8026\u5408\u4e00\u6837\uff0c\u6211\u4eec\u53ea\u8981\u638c\u63e1\u597d\u5e73\u8861\u5373\u53ef\u3002\u4e0b\u9762\u6211\u4eec\u5c06\u4e0a\u9762\u7684 if else \u6a21\u5f0f\u6539\u4e3a\u8d23\u4efb\u94fe\u6a21\u5f0f\u770b\u770b\u662f\u5426\u7b26\u5408\u8bbe\u8ba1\u539f\u5219\u3002\n<\/p>\n<p>\n\t\u518d\u5f00\u59cb\u4e4b\u524d\uff0c\u6211\u4eec\u5148\u6765\u770b\u4e00\u4e0b\u8d23\u4efb\u94fe\u6a21\u5f0f\u7684\u7ed3\u6784\u56fe\uff1a\n<\/p>\n<p>\n\t<img decoding=\"async\" alt=\"\u8d23\u4efb\u94fe\u6a21\u5f0f\" src=\"https:\/\/raw.githubusercontent.com\/xmt1139057136\/xttblog\/master\/handler.gif\" style=\"width: 712px;height: 462px\" \/>\n<\/p>\n<p>\n\t\u6309\u7167\u4e0a\u9762\u7684\u7ed3\u6784\u56fe\uff0c\u6211\u4eec\u7167\u846b\u82a6\u753b\u74e2\u5373\u53ef\u3002\u9700\u8981\u8bf4\u660e\u7684\u4e00\u70b9\u662f\uff0c\u8d23\u4efb\u94fe\u6a21\u5f0f\u6211\u76f8\u4fe1\u5927\u5bb6\u90fd\u4e0d\u6a21\u5f0f\u4e86\uff0c\u4f46\u662f\u5927\u591a\u6570\u4eba\u7406\u89e3\u5b83\uff0c\u5c31\u662f\u4e0d\u4f1a\u7528\uff0c\u6216\u8005\u8bf4\u4e0d\u77e5\u9053\u7528\u5728\u4ec0\u4e48\u6837\u7684\u573a\u666f\uff0c\u6240\u4ee5\u4e0a\u56fe\u4e2d\u7684\u6bcf\u4e2a\u7c7b\u6211\u5c31\u4e0d\u5728\u7ec6\u8bf4\uff0c\u76f4\u63a5\u7565\u8fc7\u3002\n<\/p>\n<p>\n\t\u6309\u7167\u4e0a\u56fe\uff0c\u6211\u4eec\u5148\u62bd\u8c61\u4e00\u4e2a Handler\uff0c\u4ee3\u7801\u5982\u4e0b\uff1a\n<\/p>\n<pre class=\"brush:java;\">\r\nabstract class Handler {  \r\n    \/\/\u7ef4\u6301\u5bf9\u4e0b\u5bb6\u7684\u5f15\u7528  \r\n    protected Handler successor;  \r\n      \r\n    public void setSuccessor(Handler successor) {  \r\n        this.successor=successor;  \r\n    }  \r\n      \r\n    public abstract void handleRequest(String request);  \r\n}<\/pre>\n<p>\n\t\u7136\u540e\u5c31\u662f Handler \u7684\u5b9e\u73b0\u7c7b\uff0c\u4e5f\u5c31\u662f\u5ba1\u6279\u5904\u7406\u7c7b\uff1a\n<\/p>\n<pre class=\"brush:java;\">\r\npublic class ConcreteHandler extends Handler {  \r\n    public void handleRequest(String request) {  \r\n        if (\u8bf7\u6c42\u6ee1\u8db3\u6761\u4ef6) {  \r\n            \/\/\u5904\u7406\u8bf7\u6c42  \r\n        }  else {  \r\n            this.successor.handleRequest(request);  \/\/\u8f6c\u53d1\u8bf7\u6c42  \r\n        }  \r\n    }  \r\n} <\/pre>\n<p>\n\t\u4f2a\u4ee3\u7801\u5199\u5b8c\u540e\uff0c\u662f\u4e0d\u662f\u611f\u89c9\u548c\u4e0a\u9762\u6ca1\u4ec0\u4e48\u533a\u522b\u3002\u662f\u7684\u529f\u80fd\u4e0a\u662f\u6ca1\u6709\u4ec0\u4e48\u533a\u522b\uff0c\u4f46\u662f\u5728\u4ee3\u7801\u7684\u7ef4\u62a4\u4e0a\u66f4\u65b9\u4fbf\uff0c\u4e5f\u66f4\u7b26\u5408\u6211\u4eec\u7684\u8bbe\u8ba1\u539f\u5219\u3002\n<\/p>\n<p>\n\t\u5e38\u89c1\u7684\u7b26\u5408\u8d23\u4efb\u94fe\u6a21\u5f0f\u7684\u8fd8\u6709\u5904\u7406\u5404\u79cd\u8bf7\u6c42\u62a5\u6587\uff0c\u4f8b\u5982 dubbo \u4e2d\u7684\u7528\u5230\u7684\u8d23\u4efb\u94fe\u6a21\u5f0f\u3002\n<\/p>\n<p>\n\t\u5b66\u4e60\u8d23\u4efb\u94fe\u6a21\u5f0f\uff0c\u6211\u4eec\u66f4\u591a\u7684\u662f\u8981\u7528\uff0c\u800c\u4e0d\u662f\u4e3a\u4e86\u5b66\u4e60\u800c\u5b66\u4e60\uff01<\/p>\n<!-- <audio autoplay=\"autoplay\" height=\"100\" width=\"100\" hidden=\"true\"><source src=\"https:\/\/c.coka.la\/orAvPR.mp3\" type=\"audio\/mp3\"\/><\/audio><img decoding=\"async\" src=\"https:\/\/images.weserv.nl\/?url=https:\/\/ws3.sinaimg.cn\/large\/8fa5dcfcgy1g4em3rzar5j20ib089ae0.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/> --><p><!-- <img decoding=\"async\" src=\"https:\/\/raw.githubusercontent.com\/xmt1139057136\/xttblog\/master\/8fa5dcfcgy1g4em3rzar5j20ib089ae0.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/>--><img decoding=\"async\" src=\"https:\/\/saas.51autoparts.cn\/api\/admin\/sys-file\/oss\/file?fileName=84db51f8561e448f9a4fda2eff0811f9.jpg\" alt=\"\u4e1a\u4f59\u8349\u516c\u4f17\u53f7\"\/><\/p><p>\u6700\u540e\uff0c\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u4e2a\u4eba\u5fae\u4fe1\u516c\u4f17\u53f7\uff1a\u4e1a\u4f59\u8349\uff08yyucao\uff09\uff01<b>\u53ef\u52a0\u4f5c\u8005\u5fae\u4fe1\u53f7\uff1a<font color=\"red\">xttblog2<\/font>\u3002\u5907\u6ce8\uff1a\u201c1\u201d\uff0c\u6dfb\u52a0\u535a\u4e3b\u5fae\u4fe1\u62c9\u4f60\u8fdb\u5fae\u4fe1\u7fa4\u3002\u5907\u6ce8\u9519\u8bef\u4e0d\u4f1a\u540c\u610f\u597d\u53cb\u7533\u8bf7\u3002<\/b>\u518d\u6b21\u611f\u8c22\u60a8\u7684\u5173\u6ce8\uff01\u540e\u7eed\u6709\u7cbe\u5f69\u5185\u5bb9\u4f1a\u7b2c\u4e00\u65f6\u95f4\u53d1\u7ed9\u60a8\uff01\u539f\u521b\u6587\u7ae0\u6295\u7a3f\u8bf7\u53d1\u9001\u81f3532009913@qq.com\u90ae\u7bb1\u3002\u5546\u52a1\u5408\u4f5c\u4e5f\u53ef\u6dfb\u52a0\u4f5c\u8005\u5fae\u4fe1\u8fdb\u884c\u8054\u7cfb\uff01<\/p><p>\u672c\u6587\u539f\u6587\u51fa\u5904\uff1a<a href=\"https:\/\/www.xttblog.com\">\u4e1a\u4f59\u8349<\/a>\uff1a &raquo; <a href=\"https:\/\/www.xttblog.com\/?p=3058\">\u8bf7\u5c06\u4f60\u7684 if else \u8bbe\u8ba1\u6210\u8d23\u4efb\u94fe\u6a21\u5f0f\uff01<\/a><\/p><!-- <div class=\"bd-reward-stl\"><button id=\"bdRewardBtn\"><span><\/span><\/button><\/div> -->","protected":false},"excerpt":{"rendered":"<p>\u6211\u53ea\u60f3\u95ee\u4f60\u4e00\u53e5\uff0c\u4f60\u771f\u7684\u61c2 if else \u5417\uff1f\u771f\u7684\u61c2\u8bbe\u8ba1\u6a21\u5f0f\u5417\uff1f\u771f\u7684\u662f\u9ad8\u7ea7\u5f00\u53d1\u4ea6\u6216\u662f\u67b6\u6784\u5e08\u5417\uff1f\u8bf7\u770b\u770b\u4f60\u7684\u4ee3\u7801  [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,6],"tags":[1144,106,79,1143,1684],"class_list":["post-3058","post","type-post","status-publish","format-standard","hentry","category-java","category-yyzt","tag-1144","tag-106","tag-79","tag-1143","tag-1684"],"_links":{"self":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3058","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3058"}],"version-history":[{"count":1,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3058\/revisions"}],"predecessor-version":[{"id":3059,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=\/wp\/v2\/posts\/3058\/revisions\/3059"}],"wp:attachment":[{"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3058"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3058"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xttblog.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3058"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}