{"id":802,"date":"2021-12-18T18:18:43","date_gmt":"2021-12-18T10:18:43","guid":{"rendered":"https:\/\/blog.cauchyschwarz.com\/?p=802"},"modified":"2021-12-18T18:44:03","modified_gmt":"2021-12-18T10:44:03","slug":"%e8%ae%be%e8%ae%a1%e6%a8%a1%e5%bc%8f","status":"publish","type":"post","link":"https:\/\/blog.cauchyschwarz.com\/?p=802","title":{"rendered":"Head First\u8bbe\u8ba1\u6a21\u5f0f"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 ez-toc-wrap-right counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-69e5e258a4839\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-69e5e258a4839\" checked aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#OO%E5%9F%BA%E7%A1%80\" >OO\u57fa\u7840<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#OO%E5%8E%9F%E5%88%99\" >OO\u539f\u5219<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#OO%E6%A8%A1%E5%BC%8F\" >OO\u6a21\u5f0f<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E7%AD%96%E7%95%A5%E6%A8%A1%E5%BC%8F\" >\u7b56\u7565\u6a21\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E8%A7%82%E5%AF%9F%E8%80%85%E6%A8%A1%E5%BC%8F\" >\u89c2\u5bdf\u8005\u6a21\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E8%A3%85%E9%A5%B0%E8%80%85%E6%A8%A1%E5%BC%8F\" >\u88c5\u9970\u8005\u6a21\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E5%8D%95%E4%BE%8B%E6%A8%A1%E5%BC%8FSingleton_Pattern\" >\u5355\u4f8b\u6a21\u5f0f(Singleton Pattern)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E7%AE%80%E5%8D%95%E5%B7%A5%E5%8E%82\" >\u7b80\u5355\u5de5\u5382<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E5%B7%A5%E5%8E%82%E6%A8%A1%E5%BC%8F\" >\u5de5\u5382\u6a21\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E6%8A%BD%E8%B1%A1%E5%B7%A5%E5%8E%82%E6%A8%A1%E5%BC%8F\" >\u62bd\u8c61\u5de5\u5382\u6a21\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E5%91%BD%E4%BB%A4%E6%A8%A1%E5%BC%8F\" >\u547d\u4ee4\u6a21\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E6%A8%A1%E6%9D%BF%E6%96%B9%E6%B3%95%E6%A8%A1%E5%BC%8F\" >\u6a21\u677f\u65b9\u6cd5\u6a21\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E9%80%82%E9%85%8D%E5%99%A8%E6%A8%A1%E5%BC%8F\" >\u9002\u914d\u5668\u6a21\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E5%A4%96%E8%A7%82%E6%A8%A1%E5%BC%8FFacade_Pattern\" >\u5916\u89c2\u6a21\u5f0f(Facade Pattern)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E8%BF%AD%E4%BB%A3%E5%99%A8%E6%A8%A1%E5%BC%8F\" >\u8fed\u4ee3\u5668\u6a21\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E7%BB%84%E5%90%88%E6%A8%A1%E5%BC%8F\" >\u7ec4\u5408\u6a21\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E7%8A%B6%E6%80%81%E6%A8%A1%E5%BC%8F\" >\u72b6\u6001\u6a21\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E4%BB%A3%E7%90%86%E6%A8%A1%E5%BC%8F\" >\u4ee3\u7406\u6a21\u5f0f<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=802\/#%E7%BB%93%E6%9D%9F\" >\u7ed3\u675f<\/a><\/li><\/ul><\/nav><\/div>\n<h1 class=\"wp-block-heading\" id=\"oo%E5%9F%BA%E7%A1%80\"><span class=\"ez-toc-section\" id=\"OO%E5%9F%BA%E7%A1%80\"><\/span><strong>OO\u57fa\u7840<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<ul class=\"wp-block-list\"><li>\u62bd\u8c61<\/li><li>\u5c01\u88c5<\/li><li>\u591a\u6001<\/li><li>\u7ee7\u627f<\/li><\/ul>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"oo%E5%8E%9F%E5%88%99\"><span class=\"ez-toc-section\" id=\"OO%E5%8E%9F%E5%88%99\"><\/span><strong>OO\u539f\u5219<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<ul class=\"wp-block-list\"><li>\u627e\u51fa\u5e94\u7528\u4e2d\u53ef\u80fd\u9700\u8981\u53d8\u5316\u4e4b\u5904\uff0c\u628a\u5b83\u4eec\u72ec\u7acb\u51fa\u6765\uff0c\u4e0d\u8981\u548c\u90a3\u4e9b\u4e0d\u9700\u8981\u53d8\u5316\u7684\u4ee3\u7801\u6df7\u5728\u4e00\u8d77\u3002<\/li><li>\u9488\u5bf9\u63a5\u53e3\u7f16\u7a0b\uff0c\u800c\u4e0d\u662f\u9488\u5bf9\u5b9e\u73b0\u7f16\u7a0b\u3002<\/li><li>\u591a\u7528\u7ec4\u5408\uff0c\u5c11\u7528\u7ee7\u627f\u3002<\/li><li>\u4e3a\u4e86\u4ea4\u4e92\u5bf9\u8c61\u4e4b\u95f4\u7684\u677e\u8026\u5408\u8bbe\u8ba1\u800c\u52aa\u529b\u3002<\/li><li>\u7c7b\u5e94\u8be5\u5bf9\u6269\u5c55\u5f00\u653e\uff0c\u5bf9\u4fee\u6539\u5173\u95ed(\u5f00\u653e-\u5173\u95ed\u539f\u5219)\u3002<\/li><li>\u4f9d\u8d56\u62bd\u8c61\uff0c\u4e0d\u8981\u4f9d\u8d56\u5177\u4f53\u7c7b(\u4f9d\u8d56\u5012\u7f6e\u539f\u5219)\u3002<\/li><li>\u597d\u83b1\u575e\u539f\u5219\uff1a\u522b\u8c03\u7528(call)\u6211\u4eec\uff0c\u6211\u4eec\u4f1a\u8c03\u7528(call)\u4f60\u3002<br>\u5728\u597d\u83b1\u575e\u539f\u5219\u4e0b\uff0c\u6211\u4eec\u5141\u8bb8\u4f4e\u5c42\u7ec4\u4ef6\u5c06\u81ea\u5df1\u6302\u94a9\u5230\u7cfb\u7edf\u4e0a\uff0c\u4f46\u662f\u9ad8\u5c42\u7ec4\u4ef6\u4f1a\u51b3\u5b9a\u4ec0\u4e48\u65f6\u5019\u548c\u600e\u6837\u4f7f\u7528\u8fd9\u4e9b\u4f4e\u5c42\u7ec4\u4ef6\u3002\u6362\u53e5\u8bdd\u8bf4\uff0c\u9ad8\u5c42\u7ec4\u4ef6\u5bf9\u5f85\u4f4e\u5c42\u7ec4\u4ef6\u7684\u65b9\u5f0f\u201c\u522b\u8c03\u7528\u6211\u4eec\uff0c\u6211\u4eec\u4f1a\u8c03\u7528\u4f60\u201d\u3002<\/li><li>&#8220;\u6700\u5c11\u77e5\u8bc6&#8221;\u539f\u5219\uff1a\u53ea\u548c\u4f60\u7684\u5bc6\u53cb\u8c08\u8bdd(\u51cf\u5c11\u5bf9\u8c61\u4e4b\u95f4\u7684\u4ea4\u4e92)\u3002<br>\u8fd9\u4e2a\u539f\u5219\u5e0c\u671b\u6211\u4eec\u5728\u8bbe\u8ba1\u4e2d\uff0c\u4e0d\u8981\u8ba9\u592a\u591a\u7684\u7c7b\u8026\u5408\u5728\u4e00\u8d77\uff0c\u514d\u5f97\u4fee\u6539\u7cfb\u7edf\u4e2d\u4e00\u90e8\u5206\uff0c\u4f1a\u5f71\u54cd\u5230\u5176\u4ed6\u90e8\u5206\u3002\u5982\u679c\u8bb8\u591a\u7c7b\u4e4b\u95f4\u4e92\u76f8\u4f9d\u8d56\uff0c\u90a3\u4e48\u8fd9\u4e2a\u7cfb\u7edf\u5c31\u4f1a\u53d8\u6210\u4e00\u4e2a\u6613\u788e\u7684\u7cfb\u7edf\uff0c\u5b83\u9700\u8981\u82b1\u8bb8\u591a\u6210\u672c\u7ef4\u62a4\uff0c\u4e5f\u4f1a\u56e0\u4e3a\u592a\u590d\u6742\u800c\u4e0d\u5bb9\u6613\u88ab\u5176\u4ed6\u4eba\u4e86\u89e3\u3002<br>\u8fd9\u4e2a\u539f\u5219\u4e0e\u58a8\u5fd2\u8033\u6cd5\u5219(Law of Demeter)\u662f\u540c\u4e00\u56de\u4e8b\u3002<br>\u8fd9\u4e2a\u539f\u5219\u7684\u7f3a\u70b9\u662f\u4f60\u53ef\u80fd\u4e3a\u4e86\u9075\u5faa\u8fd9\u4e2a\u539f\u5219\u800c\u9020\u51fa\u5f88\u591a\u7528\u4e8e\u5305\u88c5\u7684\u7c7b\u3002<\/li><li>\u8bbe\u8ba1\u539f\u5219\uff1a\u4e00\u4e2a\u7c7b\u5e94\u8be5\u53ea\u6709\u4e00\u4e2a\u5f15\u8d77\u53d8\u5316\u7684\u539f\u56e0\u3002<ul><li>\u5185\u805a(cohesion)\uff1a\u7528\u6765\u8861\u91cf\u4e00\u4e2a\u7c7b\u6216\u6a21\u5757\u7d27\u5bc6\u5730\u8fbe\u5230\u5355\u4e00\u76ee\u7684\u6216\u8d23\u4efb\u3002<br>\u5f53\u4e00\u4e2a\u6a21\u5757\u6216\u4e00\u4e2a\u7c7b\u88ab\u8bbe\u8ba1\u6210\u53ea\u652f\u6301\u4e00\u7ec4\u76f8\u5173\u7684\u529f\u80fd\u65f6\uff0c\u6211\u4eec\u8bf4\u5b83\u5177\u6709\u9ad8\u5185\u805a\uff1b\u53cd\u4e4b\uff0c\u5f53\u88ab\u8bbe\u8ba1\u6210\u652f\u6301\u4e00\u7ec4\u4e0d\u76f8\u5173\u7684\u5171\u80fd\u65f6\uff0c\u6211\u4eec\u8bf4\u5b83\u5177\u6709\u4f4e\u5185\u805a\u3002\u5185\u805a\u662f\u4e00\u4e2a\u6bd4\u5355\u4e00\u8d23\u4efb\u539f\u5219\u66f4\u666e\u904d\u7684\u6982\u5ff5\uff0c\u4f46\u4e24\u8005\u5176\u5b9e\u5173\u7cfb\u662f\u5f88\u5bc6\u5207\u7684\u3002\u9075\u5b88\u8fd9\u4e2a\u539f\u5219\u7684\u7c7b\u5bb9\u6613\u5177\u6709\u5f88\u9ad8\u7684\u51dd\u805a\u529b\uff0c\u800c\u4e14\u6bd4\u80cc\u8d1f\u8bb8\u591a\u8d23\u4efb\u7684\u4f4e\u5185\u805a\u7c7b\u66f4\u5bb9\u6613\u7ef4\u62a4\u3002<\/li><\/ul><\/li><\/ul>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"oo%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"OO%E6%A8%A1%E5%BC%8F\"><\/span><strong>OO\u6a21\u5f0f<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E7%AD%96%E7%95%A5%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E7%AD%96%E7%95%A5%E6%A8%A1%E5%BC%8F\"><\/span>\u7b56\u7565\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>\u7b56\u7565\u6a21\u5f0f<\/strong>\u5b9a\u4e49\u4e86\u7b97\u6cd5\u65cf\uff0c\u5206\u522b\u5c01\u88c5\u8d77\u6765\uff0c\u8ba9\u5b83\u4eec\u4e4b\u95f4\u53ef\u4ee5\u4e92\u76f8\u66ff\u6362\uff0c\u6b64\u6a21\u5f0f\u8ba9\u7b97\u6cd5\u7684\u53d8\u5316\u72ec\u7acb\u4e8e\u4f7f\u7528\u7b97\u6cd5\u7684\u5ba2\u6237\u3002<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E8%A7%82%E5%AF%9F%E8%80%85%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E8%A7%82%E5%AF%9F%E8%80%85%E6%A8%A1%E5%BC%8F\"><\/span>\u89c2\u5bdf\u8005\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>\u89c2\u5bdf\u8005\u6a21\u5f0f<\/strong>&nbsp;\u5b9a\u4e49\u4e86\u5bf9\u8c61\u4e4b\u95f4\u7684\u4e00\u5bf9\u591a\u4f9d\u8d56\uff0c\u8fd9\u6837\u4e00\u6765\uff0c\u5f53\u4e00\u4e2a\u5bf9\u8c61\u6539\u53d8\u72b6\u6001\u65f6\uff0c\u5b83\u7684\u6240\u6709\u4f9d\u8d56\u8005\u90fd\u4f1a\u6536\u5230\u901a\u77e5\u5e76\u81ea\u52a8\u66f4\u65b0\u3002<\/li><\/ul>\n\n\n\n<p>UML\u793a\u610f\u56fe\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"611\" height=\"678\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_observer.png\" alt=\"\" class=\"wp-image-803\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_observer.png 611w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_observer-270x300.png 270w\" sizes=\"auto, (max-width: 611px) 100vw, 611px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E8%A3%85%E9%A5%B0%E8%80%85%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E8%A3%85%E9%A5%B0%E8%80%85%E6%A8%A1%E5%BC%8F\"><\/span>\u88c5\u9970\u8005\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>\u88c5\u9970\u8005\u6a21\u5f0f<\/strong>&nbsp;\u52a8\u6001\u5730\u5c06\u8d23\u4efb\u9644\u52a0\u5230\u5bf9\u8c61\u4e0a\u3002\u82e5\u8981\u6269\u5c55\u529f\u80fd\uff0c\u88c5\u9970\u8005\u63d0\u4f9b\u4e86\u6bd4\u7ee7\u627f\u66f4\u6709\u5f39\u6027\u7684\u66ff\u4ee3\u65b9\u6848\u3002<\/li><\/ul>\n\n\n\n<p>UML\u793a\u610f\u56fe\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"635\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_decorator-1024x635.png\" alt=\"\" class=\"wp-image-804\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_decorator-1024x635.png 1024w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_decorator-300x186.png 300w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_decorator-768x476.png 768w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_decorator-670x416.png 670w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_decorator.png 1067w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E5%8D%95%E4%BE%8B%E6%A8%A1%E5%BC%8Fsingleton-pattern\"><span class=\"ez-toc-section\" id=\"%E5%8D%95%E4%BE%8B%E6%A8%A1%E5%BC%8FSingleton_Pattern\"><\/span>\u5355\u4f8b\u6a21\u5f0f(Singleton Pattern)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>\u5355\u4ef6\u6a21\u5f0f<\/strong>\u786e\u4fdd\u4e00\u4e2a\u7c7b\u53ea\u6709\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u5e76\u63d0\u4f9b\u4e00\u4e2a\u5168\u5c40\u8bbf\u95ee\u70b9\u3002<br>\u5bf9\u4e8e\u591a\u7ebf\u7a0b\u5e94\u7528\u573a\u666f\u4e0b\u7684\u5355\u4f8b\u6a21\u5f0f\uff0c\u53ef\u80fd\u4f1a\u51fa\u73b0\u8fd9\u6837\u7684\u95ee\u9898\uff1a\u591a\u4e2a\u7ebf\u7a0b\u5728\u8981\u8bbf\u95ee\u8fd9\u4e2a\u5355\u4f8b\u65f6\uff0c\u8fd9\u4e2a\u5355\u4f8b\u8fd8\u6ca1\u6709\u5b9e\u4f8b\u5316\uff0c\u6b64\u65f6\u5b58\u5728\u7740\u8fd9\u4e2a\u5b9e\u4f8b\u5316\u8fc7\u7a0b\u7684\u540c\u6b65\u95ee\u9898\u3002\u53ef\u4ee5\u8003\u8651\u4ee5\u4e0b\u65b9\u6848\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u4f7f\u7528synchronized\u5173\u952e\u5b57\u4fee\u9970getInstance\u65b9\u6cd5<\/li><li>\u5728\u4e00\u5f00\u59cb\u5c31\u5b9e\u4f8b\u5316\u8fd9\u4e2a\u5355\u4f8b\u800c\u4e0d\u662f\u50cf\u60ef\u4f8b\u90a3\u6837\u5c06\u5176\u8bbe\u4e3anull<\/li><li>\u53cc\u91cd\u68c0\u67e5\u52a0\u9501<br>\u7528volatile\u4fee\u9970\u5355\u4f8b\uff0c\u4e14\u53ea\u5728\u68c0\u67e5\u5355\u4f8b\u4e3a\u7a7a\u65f6\uff0c\u9700\u8981\u5b9e\u4f8b\u5316\u5355\u4f8b\u65f6\u624d\u8fdb\u884c\u540c\u6b65<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"java\" class=\"language-java\">    public class Singleton {\n\tprivate volatile static Singleton uniqueInstance;\n\tprivate Singleton() {}\n\tpublic static Singleton getInstance() {\n\t    if (uniqueInstance == null) {\n\t\tsynchronized (Singleton.class) {\n\t\t    if (uniqueInstance == null) {\n\t\t\tuniqueInstance = new Singleton();\n\t\t    }\n\t\t}\n\t    }\n\t    return uniqueInstance;\n\t}\n    }<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E7%AE%80%E5%8D%95%E5%B7%A5%E5%8E%82\"><span class=\"ez-toc-section\" id=\"%E7%AE%80%E5%8D%95%E5%B7%A5%E5%8E%82\"><\/span>\u7b80\u5355\u5de5\u5382<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>\u5e76\u4e0d\u662f\u4e00\u4e2a\u8bbe\u8ba1\u6a21\u5f0f\uff0c\u800c\u66f4\u50cf\u662f\u4e00\u79cd\u7f16\u7a0b\u4e60\u60ef<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"java\" class=\"language-java\">public class PizzaStore {\n\tSimplePizzaFactory factory;\n\n\tpublic PizzaStore(SimplePizzaFactory factory) {\n\t\tthis.factory = factory;\n\t}\n\n\tpublic Pizza orderPizza(String type) {\n\t\tPizza pizza;\n\n\t\tpizza = factory.createPizza(type);\n\n\t\tpizza.prepare();\n\t\tpizza.bake();\n\t\tpizza.cut();\n\t\tpizza.box();\n\t\treturn pizza;\n\t}\n\n\t...\n}\n\npublic class SimplePizzaFactory {\n\tpublic Pizza createPizza(String type) {\n\t\tPizza pizza = null;\n\n\t\tif (type.equals(\"cheese\")) {\n\t\t\tpizza = new CheesePizza();\n\t\t} else if (type.equals(\"pepperoni\")) {\n\t\t\tpizza = new PepperoniPizza();\n\t\t} else if (type.equals(\"clam\")) {\n\t\t\tpizza = new ClamPizza();\n\t\t} else if (type.equals(\"veggie\")) {\n\t\t\tpizza = new VeggiePizza();\n\t\t}\n\n\t\treturn pizza;\n\t}\n}\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E5%B7%A5%E5%8E%82%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E5%B7%A5%E5%8E%82%E6%A8%A1%E5%BC%8F\"><\/span>\u5de5\u5382\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>\u5de5\u5382\u6a21\u5f0f<\/strong>\u5b9a\u4e49\u4e86\u4e00\u4e2a\u521b\u5efa\u5bf9\u8c61\u7684\u63a5\u53e3\uff0c\u4f46\u7531\u5b50\u7c7b\u51b3\u5b9a\u8981\u5b9e\u4f8b\u5316\u7684\u7c7b\u662f\u54ea\u4e00\u4e2a\u3002\u5de5\u5382\u65b9\u6cd5\u8ba9\u7c7b\u628a\u5b9e\u4f8b\u5316\u63a8\u8fdf\u5230\u5b50\u7c7b\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"710\" height=\"467\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_factory.png\" alt=\"\" class=\"wp-image-805\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_factory.png 710w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_factory-300x197.png 300w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_factory-670x441.png 670w\" sizes=\"auto, (max-width: 710px) 100vw, 710px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E6%8A%BD%E8%B1%A1%E5%B7%A5%E5%8E%82%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E6%8A%BD%E8%B1%A1%E5%B7%A5%E5%8E%82%E6%A8%A1%E5%BC%8F\"><\/span>\u62bd\u8c61\u5de5\u5382\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>\u62bd\u8c61\u5de5\u5382\u6a21\u5f0f<\/strong>\u63d0\u4f9b\u4e00\u4e2a\u63a5\u53e3\uff0c\u7528\u4e8e\u521b\u5efa\u76f8\u5173\u6216\u4f9d\u8d56\u5bf9\u8c61\u7684\u5bb6\u65cf\uff0c\u800c\u4e0d\u9700\u8981\u660e\u786e\u6307\u5b9a\u5177\u4f53\u7c7b\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"992\" height=\"456\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_abstract_factory.png\" alt=\"\" class=\"wp-image-806\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_abstract_factory.png 992w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_abstract_factory-300x138.png 300w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_abstract_factory-768x353.png 768w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_abstract_factory-670x308.png 670w\" sizes=\"auto, (max-width: 992px) 100vw, 992px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E5%91%BD%E4%BB%A4%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E5%91%BD%E4%BB%A4%E6%A8%A1%E5%BC%8F\"><\/span>\u547d\u4ee4\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>\u547d\u4ee4\u6a21\u5f0f<\/strong>\u5c06\u201c\u8bf7\u6c42\u201d\u5c01\u88c5\u6210\u5bf9\u8c61\uff0c\u4ee5\u4fbf\u4f7f\u7528\u4e0d\u540c\u7684\u8bf7\u6c42\u3001\u961f\u5217\u6216\u8005\u65e5\u5fd7\u6765\u53c2\u6570\u5316\u5176\u4ed6\u5bf9\u8c61\u3002\u547d\u4ee4\u6a21\u5f0f\u4e5f\u652f\u6301\u53ef\u64a4\u9500\u64cd\u4f5c\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"822\" height=\"508\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_cmd.png\" alt=\"\" class=\"wp-image-809\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_cmd.png 822w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_cmd-300x185.png 300w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_cmd-768x475.png 768w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_cmd-670x414.png 670w\" sizes=\"auto, (max-width: 822px) 100vw, 822px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E6%A8%A1%E6%9D%BF%E6%96%B9%E6%B3%95%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E6%A8%A1%E6%9D%BF%E6%96%B9%E6%B3%95%E6%A8%A1%E5%BC%8F\"><\/span>\u6a21\u677f\u65b9\u6cd5\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>\u6a21\u677f\u65b9\u6cd5\u6a21\u5f0f<\/strong>\u5728\u4e00\u4e2a\u65b9\u6cd5\u4e2d\u5b9a\u4e49\u4e00\u4e2a\u7b97\u6cd5\u7684\u9aa8\u67b6\uff0c\u800c\u5c06\u4e00\u4e9b\u6b65\u9aa4\u5ef6\u8fdf\u5230\u5b50\u7c7b\u4e2d\u3002\u6a21\u677f\u65b9\u6cd5\u4f7f\u5f97\u5b50\u7c7b\u53ef\u4ee5\u5728\u4e0d\u6539\u53d8\u7b97\u6cd5\u7ed3\u6784\u7684\u60c5\u51b5\u4e0b\uff0c\u91cd\u65b0\u5b9a\u4e49\u7b97\u6cd5\u4e2d\u7684\u67d0\u4e9b\u6b65\u9aa4\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"660\" height=\"323\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_template.png\" alt=\"\" class=\"wp-image-810\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_template.png 660w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_template-300x147.png 300w\" sizes=\"auto, (max-width: 660px) 100vw, 660px\" \/><\/figure>\n\n\n\n<p>hook\uff1a\u5982\u679c\u4f60\u4e3a\u539f\u8bed\u64cd\u4f5c\u63d0\u4f9b\u4e00\u4e2a\u9ed8\u8ba4\u7684\u5b9e\u73b0\uff0c\u90a3\u4e48\u8fd9\u4e2a\u539f\u8bed\u64cd\u4f5c\u5c31\u6210\u4e3a\u4e00\u4e2a\u94a9\u5b50(hook)\u3002\u5728\u4f60\u9700\u8981\u7684\u65f6\u5019\u53ef\u4ee5\u5728\u5b50\u7c7b\u4e2d\u91cd\u5199\u8fd9\u4e2ahook\u65b9\u6cd5\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E9%80%82%E9%85%8D%E5%99%A8%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E9%80%82%E9%85%8D%E5%99%A8%E6%A8%A1%E5%BC%8F\"><\/span>\u9002\u914d\u5668\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>\u9002\u914d\u5668\u6a21\u5f0f<\/strong>\u5c06\u4e00\u4e2a\u7c7b\u7684\u63a5\u53e3\uff0c\u8f6c\u6362\u6210\u5ba2\u6237\u671f\u671b\u7684\u53e6\u4e00\u4e2a\u63a5\u53e3\u3002\u9002\u914d\u5668\u8ba9\u539f\u672c\u4e0d\u517c\u5bb9\u7684\u7c7b\u53ef\u4ee5\u5408\u4f5c\u65e0\u95f4\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"581\" height=\"224\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_adapter_object.png\" alt=\"\" class=\"wp-image-811\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_adapter_object.png 581w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_adapter_object-300x116.png 300w\" sizes=\"auto, (max-width: 581px) 100vw, 581px\" \/><\/figure>\n\n\n\n<p>\u4e0a\u9762\u7684uml\u56fe\u5176\u5b9e\u8bb2\u7684\u662f&#8221;\u5bf9\u8c61&#8221;\u9002\u914d\u5668\uff0c\u4f7f\u7528\u7684\u7ec4\u5408\u7684\u65b9\u5f0f\u3002\u53e6\u5916\u8fd8\u5b58\u5728\u7740\u201c\u7c7b\u201d\u9002\u914d\u5668\uff0c\u4f7f\u7528\u7ee7\u627f\u7684\u65b9\u5f0f\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"236\" height=\"201\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_adapter_class.png\" alt=\"\" class=\"wp-image-812\"\/><\/figure>\n\n\n\n<p>\u5bf9\u8c61\u9002\u914d\u5668\u9700\u8981\u7f16\u7a0b\u8bed\u8a00\u63d0\u4f9b\u591a\u91cd\u7ee7\u627f\u7684\u652f\u6301\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E5%A4%96%E8%A7%82%E6%A8%A1%E5%BC%8Ffacade-pattern\"><span class=\"ez-toc-section\" id=\"%E5%A4%96%E8%A7%82%E6%A8%A1%E5%BC%8FFacade_Pattern\"><\/span>\u5916\u89c2\u6a21\u5f0f(Facade Pattern)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>\u5916\u89c2\u6a21\u5f0f<\/strong>\u63d0\u4f9b\u4e86\u4e00\u4e2a\u7edf\u4e00\u7684\u63a5\u53e3\uff0c\u7528\u6765\u8bbf\u95ee\u5b50\u7cfb\u7edf\u4e2d\u7684\u4e00\u7fa4\u63a5\u53e3\u3002\u5916\u89c2\u5b9a\u4e49\u4e86\u4e00\u4e2a\u9ad8\u5c42\u63a5\u53e3\uff0c\u8ba9\u5b50\u7cfb\u7edf\u66f4\u5bb9\u6613\u4f7f\u7528\u3002<br>\u7b80\u8a00\u4e4b\uff1a\u9690\u85cf\u7ec6\u8282\uff0c\u7b80\u5316\u63a5\u53e3\uff0c\u8ba9\u5ba2\u6237\u4e0e\u4f4e\u5c42\u7ec4\u4ef6\u89e3\u8026\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E8%BF%AD%E4%BB%A3%E5%99%A8%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E8%BF%AD%E4%BB%A3%E5%99%A8%E6%A8%A1%E5%BC%8F\"><\/span>\u8fed\u4ee3\u5668\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>\u8fed\u4ee3\u5668\u6a21\u5f0f<\/strong>\u63d0\u4f9b\u4e00\u79cd\u65b9\u6cd5\u987a\u5e8f\u8bbf\u95ee\u4e00\u4e2a\u805a\u5408\u5bf9\u8c61\u4e2d\u7684\u5404\u4e2a\u5143\u7d20\uff0c\u800c\u53c8\u4e0d\u66b4\u9732\u5176\u5185\u90e8\u7684\u8868\u793a\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"310\" height=\"417\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_iterator.png\" alt=\"\" class=\"wp-image-813\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_iterator.png 310w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_iterator-223x300.png 223w\" sizes=\"auto, (max-width: 310px) 100vw, 310px\" \/><\/figure>\n\n\n\n<p>\u8fd9\u91cc\u8bb2\u8ff0\u7684\u8fed\u4ee3\u5668\u662f\u201c\u5185\u90e8\u201d\u8fed\u4ee3\u5668\uff0c\u5373\u6211\u4eec\u5728\u624b\u52a8\u63a7\u5236\u8fed\u4ee3\u5668\u7684\u79fb\u52a8(\u901a\u8fc7<em>next<\/em>\u64cd\u4f5c)\uff0c\u800c\u201c\u5916\u90e8\u201d\u8fed\u4ee3\u5668\u5219\u662f\u7c7b\u4f3c\u4e8e\u6d41\u8ba1\u7b97\u90a3\u79cd\u6211\u4eec\u544a\u8bc9\u8fed\u4ee3\u5668\u5728\u53d6\u5f97\u6bcf\u4e2a\u5143\u7d20\u65f6\u505a\u4ec0\u4e48\u4e8b\u60c5\u7684\u8fed\u4ee3\u5668\uff1b<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E7%BB%84%E5%90%88%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E7%BB%84%E5%90%88%E6%A8%A1%E5%BC%8F\"><\/span>\u7ec4\u5408\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>\u7ec4\u5408\u6a21\u5f0f<\/strong>\u5141\u8bb8\u4f60\u5c06\u5bf9\u8c61\u7ec4\u5408\u6210\u6811\u5f62\u7ed3\u6784\u6765\u8868\u73b0\u201c\u6574\u4f53\/\u90e8\u5206\u201d\u5c42\u6b21\u7ed3\u6784\u3002\u7ec4\u5408\u80fd\u8ba9\u5ba2\u6237\u4ee5\u4e00\u81f4\u7684\u65b9\u5f0f\u5904\u7406\u4e2a\u522b\u5bf9\u8c61\u4ee5\u53ca\u5bf9\u8c61\u7ec4\u5408\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"467\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_component-1024x467.png\" alt=\"\" class=\"wp-image-814\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_component-1024x467.png 1024w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_component-300x137.png 300w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_component-768x350.png 768w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_component-670x305.png 670w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_component.png 1097w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>\u4e00\u4e2a\u7ec4\u5408\u8fed\u4ee3\u5668\uff0c\u4e0d\u4ec5\u904d\u5386\u7ec4\u4ef6\u5185\u7684\u83dc\u5355\u9879\uff0c\u800c\u4e14\u786e\u4fdd\u6240\u6709\u7684\u5b50\u83dc\u5355(\u4ee5\u53ca\u5b50\u5b50\u83dc\u5355&#8230;&#8230;)\u90fd\u88ab\u5305\u542b\u8fdb\u6765\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"java\" class=\"language-java\">import java.util.*;\n\npublic class CompositeIterator implements Iterator {\n\tStack stack = new Stack();\n\n\tpublic CompositeIterator(Iterator iterator) {\n\t\tstack.push(iterator);\n\t}\n\n\tpublic Object next() {\n\t\tif (hasNext()) {\n\t\t\tIterator iterator = (Iterator) stack.peek();\n\t\t\tMenuComponent  component = (MenuComponent) iterator.next();\n\t\t\tif (component instanceof Menu) {\n\t\t\t\tstack.push(component.createIterator());\n\t\t\t}\n\t\t\treturn component;\n\t\t} else {\n\t\t\treturn null;\n\t\t}\n\t}\n\n\tpublic boolean hasNext() {\n\t\tif (stack.empty()) {\n\t\t\treturn false;\n\t\t} else {\n\t\t\tIterator iterator = (Iterator) stack.peek();\n\t\t\tif (!iterator.hasNext()) {\n\t\t\t\tstack.pop();\n\t\t\t\treturn hasNext();\n\t\t\t} else {\n\t\t\t\treturn true;\n\t\t\t}\n\t\t}\n\t}\n\n\tpublic void remove() {\n\t\tthrow new UnsupportedOperationException();\n\t}\n}\n<\/code><\/pre>\n\n\n\n<p><strong>\u7a7a\u8fed\u4ee3\u5668(NullIterator)<\/strong>\uff1a\u8fd4\u56de\u4e00\u4e2a\u8fed\u4ee3\u5668\uff0c\u800c\u8fd9\u4e2a\u8fed\u4ee3\u5668\u7684hasNext()\u6c38\u8fdc\u8fd4\u56defalse\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"java\" class=\"language-java\">import java.util.Iterator;\n\npublic class NullIterator implements Iterator {\n\tpublic Object next() {\n\t\treturn null;\n\t}\n\n\tpublic boolean hasNext() {\n\t\treturn false;\n\t}\n\n\tpublic void remove() {\n\t\tthrow new UnsupportedOperationException();\n\t}\n}<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E7%8A%B6%E6%80%81%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E7%8A%B6%E6%80%81%E6%A8%A1%E5%BC%8F\"><\/span>\u72b6\u6001\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>\u72b6\u6001\u6a21\u5f0f<\/strong>\u5141\u8bb8\u5bf9\u8c61\u5728\u5185\u90e8\u72b6\u6001\u6539\u53d8\u65f6\u6539\u53d8\u5b83\u7684\u884c\u4e3a\uff0c\u5bf9\u8c61\u770b\u8d77\u6765\u597d\u50cf\u4fee\u6539\u4e86\u5b83\u7684\u7c7b\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"773\" height=\"440\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_state.png\" alt=\"\" class=\"wp-image-815\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_state.png 773w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_state-300x171.png 300w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_state-768x437.png 768w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_state-670x381.png 670w\" sizes=\"auto, (max-width: 773px) 100vw, 773px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E4%BB%A3%E7%90%86%E6%A8%A1%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E4%BB%A3%E7%90%86%E6%A8%A1%E5%BC%8F\"><\/span>\u4ee3\u7406\u6a21\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>\u4ee3\u7406\u6a21\u5f0f<\/strong>\u4e3a\u53e6\u4e00\u4e2a\u5bf9\u8c61\u63d0\u4f9b\u4e00\u4e2a\u66ff\u8eab\u6216\u5360\u4f4d\u7b26\u4ee5\u63a7\u5236\u5bf9\u8fd9\u4e2a\u5bf9\u8c61\u7684\u8bbf\u95ee\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"671\" height=\"425\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_proxy.png\" alt=\"\" class=\"wp-image-816\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_proxy.png 671w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern_proxy-300x190.png 300w\" sizes=\"auto, (max-width: 671px) 100vw, 671px\" \/><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"%E7%BB%93%E6%9D%9F\"><span class=\"ez-toc-section\" id=\"%E7%BB%93%E6%9D%9F\"><\/span>\u7ed3\u675f<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p>\u7528\u4e66\u4e2d\u9644\u5e26\u7684\u4e00\u4e2a\u8868\u6765\u7ed3\u675f\u8fd9\u7bc7\u7b14\u8bb0\u3002\u4e3b\u8981\u662f\u5173\u4e8e\u672c\u4e66\u8be6\u7ec6\u4ecb\u7ecd\u7684\u8bbe\u8ba1\u6a21\u5f0f\u7684\u7b80\u5355\u603b\u7ed3\uff0c\u4e66\u4e2d\u672a\u8be6\u7ec6\u4ecb\u7ecd\u7684\u8bbe\u8ba1\u6a21\u5f0f\u5c31\u61d2\u5f97\u770b\u4e86\uff0c\u7b49\u4ee5\u540e\u6709\u9700\u8981\u770b\u6240\u8c13\u7684\u56db\u4eba\u5e2e\u5199\u7684\u90a3\u672c\u4ecb\u7ecd\u4e8c\u5341\u591a\u79cd\u8bbe\u8ba1\u6a21\u5f0f\u7684\u4e66\u6216\u8005\u5b66spring\u65f6\u518d\u6765\u6298\u817e\u8bbe\u8ba1\u6a21\u5f0f\u5427\u3002\u770b\u4e86\u8fd9\u672c\u4e66\u5e94\u8be5\u7b97\u662f\u5bf9\u8bbe\u8ba1\u6a21\u5f0f\u521d\u6b65\u5165\u95e8\u4e86\u3002<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>\u6a21\u5f0f<\/th><th>\u63cf\u8ff0<\/th><\/tr><\/thead><tbody><tr><td>\u88c5\u9970\u8005<\/td><td>\u5305\u88c5\u4e00\u4e2a\u5bf9\u8c61\uff0c\u4ee5\u63d0\u4f9b\u65b0\u7684\u884c\u4e3a<\/td><\/tr><tr><td>\u72b6\u6001<\/td><td>\u5c01\u88c5\u4e86\u57fa\u4e8e\u72b6\u6001\u7684\u884c\u4e3a\uff0c\u5e76\u4f7f\u7528\u59d4\u6258\u5728\u884c\u4e3a\u4e4b\u95f4\u5207\u6362<\/td><\/tr><tr><td>\u8fed\u4ee3\u5668<\/td><td>\u5728\u5bf9\u8c61\u7684\u96c6\u5408\u4e4b\u4e2d\u6e38\u8d70\uff0c\u800c\u4e0d\u66b4\u9732\u96c6\u5408\u7684\u5b9e\u73b0<\/td><\/tr><tr><td>\u5916\u89c2<\/td><td>\u7b80\u5316\u4e00\u7fa4\u7c7b\u7684\u63a5\u53e3<\/td><\/tr><tr><td>\u7b56\u7565<\/td><td>\u5c01\u88c5\u53ef\u4ee5\u4e92\u6362\u7684\u884c\u4e3a\uff0c\u5e76\u4f7f\u7528\u59d4\u6258\u6765\u51b3\u5b9a\u8981\u4f7f\u7528\u54ea\u4e00\u4e2a<\/td><\/tr><tr><td>\u4ee3\u7406<\/td><td>\u5305\u88c5\u5bf9\u8c61\uff0c\u4ee5\u63a7\u5236\u5bf9\u6b64\u5bf9\u8c61\u7684\u8bbf\u95ee<\/td><\/tr><tr><td>\u5de5\u5382\u65b9\u6cd5<\/td><td>\u7531\u5b50\u7c7b\u51b3\u5b9a\u8981\u521b\u5efa\u7684\u5177\u4f53\u7c7b\u662f\u54ea\u4e00\u4e2a<\/td><\/tr><tr><td>\u9002\u914d\u5668<\/td><td>\u5c01\u88c5\u5bf9\u8c61\uff0c\u5e76\u63d0\u4f9b\u4e0d\u540c\u7684\u63a5\u53e3<\/td><\/tr><tr><td>\u89c2\u5bdf\u8005<\/td><td>\u8ba9\u5bf9\u8c61\u80fd\u591f\u5728\u72b6\u6001\u6539\u53d8\u65f6\u88ab\u901a\u77e5<\/td><\/tr><tr><td>\u6a21\u677f\u65b9\u6cd5<\/td><td>\u7531\u5b50\u7c7b\u51b3\u5b9a\u5982\u4f55\u5b9e\u73b0\u4e00\u4e2a\u7b97\u6cd5\u4e2d\u7684\u6b65\u9aa4<\/td><\/tr><tr><td>\u7ec4\u5408<\/td><td>\u5ba2\u6237\u7528\u4e00\u81f4\u7684\u65b9\u5f0f\u5904\u7406\u5bf9\u8c61\u96c6\u5408\u548c\u5355\u4e2a\u5bf9\u8c61<\/td><\/tr><tr><td>\u5355\u4ef6<\/td><td>\u786e\u4fdd\u6709\u4e14\u53ea\u6709\u4e00\u4e2a\u5bf9\u8c61\u88ab\u521b\u5efa<\/td><\/tr><tr><td>\u62bd\u8c61\u5de5\u5382<\/td><td>\u5141\u8bb8\u5ba2\u6237\u521b\u5efa\u5bf9\u8c61\u7684\u5bb6\u65cf\uff0c\u800c\u65e0\u9700\u6307\u5b9a\u4ed6\u4eec\u7684\u5177\u4f53\u7c7b<\/td><\/tr><tr><td>\u547d\u4ee4<\/td><td>\u5c01\u88c5\u8bf7\u6c42\u6210\u4e3a\u5bf9\u8c61<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<div class=\"wp-block-file\"><a href=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern.tar.gz\">design_pattern.tar<\/a><a href=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/design_pattern.tar.gz\" class=\"wp-block-file__button\" download>\u8bbe\u8ba1\u6a21\u5f0fplantuml\u6e90\u7801\u53ca\u56fe\u7247<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"<p>OO\u57fa\u7840 \u62bd\u8c61 \u5c01\u88c5 \u591a\u6001 \u7ee7\u627f OO\u539f\u5219 \u627e\u51fa\u5e94\u7528\u4e2d\u53ef\u80fd\u9700\u8981\u53d8\u5316\u4e4b\u5904\uff0c\u628a\u5b83\u4eec\u72ec\u7acb\u51fa\u6765\uff0c\u4e0d\u8981\u548c\u90a3\u4e9b\u4e0d\u9700\u8981\u53d8\u5316\u7684\u4ee3\u7801\u6df7\u5728\u4e00\u8d77\u3002 \u9488\u5bf9\u63a5\u53e3\u7f16\u7a0b\uff0c\u800c\u4e0d\u662f\u9488\u5bf9\u5b9e\u73b0\u7f16\u7a0b\u3002 \u591a\u7528\u7ec4\u5408\uff0c\u5c11\u7528\u7ee7\u627f\u3002 \u4e3a\u4e86\u4ea4\u4e92\u5bf9\u8c61\u4e4b\u95f4&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[86,9],"class_list":["post-802","post","type-post","status-publish","format-standard","hentry","category-10","tag-86","tag-9"],"_links":{"self":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts\/802","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=802"}],"version-history":[{"count":4,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts\/802\/revisions"}],"predecessor-version":[{"id":820,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts\/802\/revisions\/820"}],"wp:attachment":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=802"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=802"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=802"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}