{"id":2134,"date":"2022-02-26T16:56:47","date_gmt":"2022-02-26T08:56:47","guid":{"rendered":"http:\/\/47.101.202.111\/?p=2134"},"modified":"2022-02-27T12:18:24","modified_gmt":"2022-02-27T04:18:24","slug":"observer-pattern","status":"publish","type":"post","link":"http:\/\/139.196.114.170\/?p=2134","title":{"rendered":"\u6df1\u5165\u6d45\u51fa\u89c2\u5bdf\u8005\u6a21\u5f0f"},"content":{"rendered":"<h3>\u89c2\u5bdf\u8005\u6a21\u5f0f\u5728\u54ea\u91cc\u5e94\u7528\uff1f<\/h3>\n<p>\u7ecf\u5e38\u5f00\u53d1\u7684\u670b\u53cb\u90fd\u719f\u6089\u4ee5\u4e0b\u573a\u666f\uff1a<\/p>\n<ul>\n<li>\u70b9\u51fb\u6309\u94ae\u54cd\u5e94\u4e00\u4e2a\u70b9\u51fb\u4e8b\u4ef6<\/li>\n<li>\u7f51\u7edc\u8bf7\u6c42\u8fd4\u56de\u62a5\u6587\u540e\u4f1a\u89e6\u53d1\u54cd\u5e94\u903b\u8f91<\/li>\n<li>\u524d\u7aef\u8981\u6839\u636e\u6570\u636e\u6e90\u7684\u53d8\u5316\u800c\u53d8\u5316<\/li>\n<li>\u6839\u636e\u952e\u9f20\u64cd\u4f5c\u5b9e\u65f6\u6e32\u67d3\u65b0\u56fe\u50cf<\/li>\n<\/ul>\n<p>\u4ece\u5e94\u7528\u573a\u666f\u4e2d\u81ea\u7136\u5730\u62bd\u8c61\u51fa\u201c\u53d8\u5316\u6e90\u201d\u548c\u201c\u54cd\u5e94\u8005\u201d\u4e24\u4e2a\u89d2\u8272\uff0c\u5728\u89c2\u5bdf\u8005\u6a21\u5f0f\u4e2d\u6211\u4eec\u5206\u522b\u79f0\u4e3a\u6d88\u606f\u7684\u201c\u53d1\u5e03\u8005\u201d\u548c\u201c\u8ba2\u9605\u8005\u201d\uff0c\u5e94\u7528\u89c2\u5bdf\u8005\u6a21\u5f0f\u53ef\u5b9e\u73b0\u4e00\u5bf9\u4e00\u3001\u4e00\u5bf9\u591a\u7684\u201c\u53d8\u5316-\u54cd\u5e94\u201d\u8fc7\u7a0b<\/p>\n<h3>\u5982\u4f55\u5f97\u77e5\u53d8\u5316\u6e90\u53d1\u751f\u4e86\u53d8\u5316\uff1f<\/h3>\n<p>\u5f88\u5bb9\u6613\u60f3\u5230\u4ee5\u4e0b\u4e24\u79cd\u65b9\u5f0f\uff1a<\/p>\n<ul>\n<li>\u62c9\u5f0f\uff1a\u8ba2\u9605\u8005\u5411\u53d1\u5e03\u8005\u53d6\u4fe1\u606f<\/li>\n<li>\u63a8\u5f0f\uff1a\u53d1\u5e03\u8005\u4e3b\u52a8\u901a\u77e5\u8ba2\u9605\u8005<\/li>\n<\/ul>\n<p>\u7ed3\u5408\u4e24\u79cd\u65b9\u6848\u8fd8\u6709\u5148\u63a8\u540e\u62c9\u5f0f\uff1a<\/p>\n<ul>\n<li>\u5148\u63a8\u540e\u62c9\uff1a\u53d1\u5e03\u8005\u544a\u77e5\u8ba2\u9605\u8005\u53d1\u751f\u53d8\u5316\uff0c\u8ba2\u9605\u8005\u6709\u7a7a\u65f6\u518d\u6765\u53d6\u8d70\u4fe1\u606f<\/li>\n<\/ul>\n<p>\u62c9\u5f0f\u65b9\u6848\u4e00\u822c\u91c7\u7528\u8f6e\u8be2\u65b9\u5f0f\uff0c\u8f6e\u8be2\u9891\u7387\u8fc7\u9ad8\u4f1a\u9020\u6210\u8d44\u6e90\u6d6a\u8d39\uff0c\u9891\u7387\u8fc7\u4f4e\u5bf9\u53d8\u5316\u7684\u54cd\u5e94\u6162<\/p>\n<p>\u63a8\u5f0f\u65b9\u6848\u5219\u6709\u4e9b\u201c\u61d2\u52a0\u8f7d\u201d\u5473\u9053\uff0c\u4ec5\u53d8\u5316\u65f6\u54cd\u5e94\uff0c\u517c\u987e\u6027\u80fd\u548c\u65f6\u6548\u66f4\u5e38\u7528<\/p>\n<p>\u89c2\u5bdf\u8005\u6a21\u5f0f\u7684\u4e24\u4e2a\u89d2\u8272\u5e76\u4e0d\u662f\u5404\u81ea\u72ec\u7acb\u8fd0\u884c\u7684\u81ea\u52a8\u673a\uff0c\u800c\u662f\u540c\u4e00\u4e2a\u8fdb\u7a0b\u4e2d\u4ee3\u7801\u7684\u6267\u884c\u6b21\u5e8f\u63a7\u5236\uff1a\u63a8\u5f0f\u65b9\u6848\u4e2d\uff0c\u63a7\u5236\u6267\u884c\u5230\u53d1\u5e03\u8005\u68c0\u6d4b\u5230\u53d8\u5316\u4ee3\u7801\u540e\uff0c\u8f6c\u53bb\u6267\u884c\u8ba2\u9605\u8005\u4e2d\u8d1f\u8d23\u54cd\u5e94\u53d8\u5316\u7684\u4ee3\u7801<\/p>\n<h3>\u5982\u4f55\u53ef\u590d\u7528\u53ef\u6269\u5c55\uff1f<\/h3>\n<h4>\u4e3a\u4ec0\u4e48\u8981\u5173\u8054\u53d1\u5e03\u8005\u548c\u8ba2\u9605\u8005\uff1f<\/h4>\n<p>\u65e2\u7136\u662f\u63a7\u5236\u6267\u884c\u6b21\u5e8f\uff0c\u53ea\u8981\u6bcf\u6b21\u5728\u5ba2\u6237\u7aef\u4f9d\u6b21\u8c03\u7528\u8ba2\u9605\u8005\u548c\u53d1\u5e03\u8005\u5373\u53ef\uff0c\u4e3a\u4f55\u8981\u641e\u5f97\u8fd9\u4e48\u590d\u6742\uff1f\u590d\u7528\u6027\uff01<\/p>\n<p>\u5e73\u5e38\u5199\u9879\u76ee\u7684\u65f6\u5019\uff0c\u76f8\u540c\u7684\u6d41\u7a0b\u548c\u903b\u8f91\u6211\u4eec\u4f1a\u62bd\u51fa\u6765\u53e6\u5199\u4e00\u4e2a\u51fd\u6570\uff0c\u6211\u4eec\u62ce\u51fa\u6765\u7684\u8fd9\u79cd\u5171\u6027\uff0c\u5c31\u662f\u201c\u62bd\u8c61\u51fa\u7684\u6a21\u5f0f\u201d\u3002\u628a\u53d1\u5e03\u8005\u548c\u8ba2\u9605\u8005\u4e4b\u95f4\u7684\u5173\u7cfb\u6253\u5305\u8d77\u6765\uff0c\u8fd9\u79cd\u5171\u6027\u8282\u7701\u4e86\u4ee3\u7801\u91cf\uff0c\u4f7f\u7528\u65f6\u4e5f\u65e0\u9700\u5173\u6ce8\u5185\u90e8\u5b9e\u73b0<\/p>\n<p>\u6211\u4eec\u60f3\u8981\u7684\u6548\u679c\u662f\u62ff\u6765\u5373\u7528\uff1a\u4f7f\u7528\u8005\u4ec5\u7ed9\u51fa\u53c2\u4e0e\u89d2\u8272\u8fd9\u5957\u6a21\u5f0f\u5373\u53ef\u8fd0\u8f6c\uff0c\u800c\u4e0d\u662f\u6bcf\u6b21\u4f7f\u7528\u90fd\u8981\u91cd\u590d\u5199\u4e24\u8005\u7684\u4ea4\u4e92<\/p>\n<h4>\u4e3a\u4ec0\u4e48\u8981\u9762\u5bf9\u62bd\u8c61\u7f16\u7a0b\uff1f<\/h4>\n<p>\u677e\u8026\u5408\uff01\u5373\u964d\u4f4e\u4f9d\u8d56\u3002\u9762\u5411\u5b9e\u73b0\u7f16\u7a0b\u65f6\u4f1a\u4ea7\u751f\u5927\u91cf\u7684\u4f9d\u8d56\uff0c\u5982\u53d1\u751f\u7c7b\u540d\u4fee\u6539\u65f6\uff0c\u6240\u6709\u542b\u6709\u8be5\u5b9e\u73b0\u7c7b\u7684\u4ee3\u7801\u90fd\u9700\u8981\u4fee\u6539\uff0c\u8fd9\u53ef\u662f\u4e00\u4e2a\u5927\u5de5\u7a0b\u3002\u800c\u9762\u5bf9\u62bd\u8c61\u7f16\u7a0b\u65f6\uff0c\u6211\u4eec\u597d\u50cf\u5728\u5199\u4e00\u4e2a\u5173\u4e8e\u7c7b\u4e4b\u95f4\u7684\u8c03\u7528\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1:1 \u6216 1:n \u5bf9\u5e94\u5173\u7cfb\u8868<\/p>\n<p>\u5b9e\u73b0\u65f6\u8981\u83b7\u5f97\u6240\u6709\u8ba2\u9605\u8005\u7684\u5f15\u7528\uff08\u6216\u8f6c\u5411\u6267\u884c\u7684\u4ee3\u7801\u5730\u5740\uff09<\/p>\n<h4>\u5982\u4f55\u5b9e\u73b0\u54cd\u5e94\u8fc7\u7a0b\uff1f<\/h4>\n<p>\u53d1\u5e03\u8005\u628a\u63a7\u5236\u4f20\u9012\u5230\u8ba2\u9605\u8005\u54cd\u5e94\u51fd\u6570\u7684\u5165\u53e3\u5730\u5740<\/p>\n<p>\u5b9e\u73b0\u65f6\u76f4\u63a5\u8c03\u7528\u5df2\u5f15\u7528\u8ba2\u9605\u8005\u7684\u54cd\u5e94\u51fd\u6570<\/p>\n<h4>\u5982\u4f55\u628a\u53d8\u5316\u4fe1\u606f\u4f20\u7ed9\u8ba2\u9605\u8005\uff1f<\/h4>\n<p>\u53ef\u5728\u8c03\u7528\u8ba2\u9605\u8005\u54cd\u5e94\u51fd\u6570\u65f6\u4f20\u53c2\u8fc7\u53bb<\/p>\n<pre lang=\"java\">\n\/**\n* \u4fe1\u606f\n*\/\npublic class Infomation { ... }\n\n\n\/**\n* \u53d1\u5e03\u8005\n*\/\npublic interface Publisher {\n    List users = new Arraylist<Subscriber>; \/\/ \u8ba2\u9605\u5173\u7cfb\u5217\u8868\n    Infomation info = null;                 \/\/ \u4fe1\u606f\u5b9e\u4f53\n\n    \/**\n    * \u5efa\u7acb\u8ba2\u9605\u5173\u7cfb\n    *\/\n    void subscribe(Subscriber user) {\n        users.add(user);\n    }\n\n    \/**\n    * \u89e3\u9664\u8ba2\u9605\u5173\u7cfb\n    *\/\n    void unsubscribe(Subscriber user) {\n        users.remove(user);\n    }\n\n    \/**\n    * \u4fe1\u606f\u53d1\u751f\u53d8\u5316\n    *\/\n    void change(Information info) {\n        this.info = info;\n        notify();\n    }\n\n    \/**\n    * \u901a\u77e5\u548c\u54cd\u5e94\u8fc7\u7a0b\uff0c\u53c2\u6570\u4f20\u9012\u4fe1\u606f\n    *\/\n    void notify() {\n        for(Subscriber s:\u3000this.users) {\n            s.onChange(info);\n        }\n    }\n}\n\n\n\/**\n* \u8ba2\u9605\u8005\n*\/\npublic interface Subscriber {\n    \/**\n    * \u5177\u4f53\u54cd\u5e94\u903b\u8f91\uff0c\u5f62\u53c2\u83b7\u53d6\u4fe1\u606f\n    *\/\n    void onChange(Information info) { ... }\n}\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u89c2\u5bdf\u8005\u6a21\u5f0f\u5728\u54ea\u91cc\u5e94\u7528\uff1f \u7ecf\u5e38\u5f00\u53d1\u7684\u670b\u53cb\u90fd\u719f\u6089\u4ee5\u4e0b\u573a\u666f\uff1a \u70b9\u51fb\u6309\u94ae\u54cd\u5e94\u4e00\u4e2a\u70b9\u51fb\u4e8b\u4ef6 \u7f51\u7edc\u8bf7\u6c42\u8fd4\u56de\u62a5\u6587\u540e\u4f1a\u89e6\u53d1\u54cd\u5e94 &hellip; <\/p>\n<p class=\"link-more\"><a href=\"http:\/\/139.196.114.170\/?p=2134\" class=\"more-link\">\u7ee7\u7eed\u9605\u8bfb<span class=\"screen-reader-text\">\u201c\u6df1\u5165\u6d45\u51fa\u89c2\u5bdf\u8005\u6a21\u5f0f\u201d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[31,1],"tags":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/posts\/2134"}],"collection":[{"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/139.196.114.170\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2134"}],"version-history":[{"count":13,"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/posts\/2134\/revisions"}],"predecessor-version":[{"id":2147,"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/posts\/2134\/revisions\/2147"}],"wp:attachment":[{"href":"http:\/\/139.196.114.170\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2134"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/139.196.114.170\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2134"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/139.196.114.170\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2134"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}