{"id":137,"date":"2021-10-30T11:34:01","date_gmt":"2021-10-30T03:34:01","guid":{"rendered":"https:\/\/www.xudongvp.com\/?p=137"},"modified":"2021-10-30T11:35:11","modified_gmt":"2021-10-30T03:35:11","slug":"%e5%8d%95%e4%be%8b%e6%a8%a1%e5%bc%8f%e4%b8%8e%e6%9c%80%e4%bd%b3%e5%ae%9e%e8%b7%b5","status":"publish","type":"post","link":"https:\/\/www.xudongvp.com\/?p=137","title":{"rendered":"\u5355\u4f8b\u6a21\u5f0f\u4e0e\u6700\u4f73\u5b9e\u8df5"},"content":{"rendered":"\n

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

\u4e00\u3001\u5355\u4f8b\u6a21\u5f0f\u7684\u5b9a\u4e49<\/h2>\n\n\n\n

\u5355\u4f8b\u6a21\u5f0f\uff08Singleton Pattern\uff09\u662f\u4e00\u4e2a\u6bd4\u8f83\u7b80\u5355\u7684\u6a21\u5f0f\uff0c\u5176\u5b9a\u4e49\u5982\u4e0b\uff1aEnsure a class has only one instance , and provide a global point of access to it .\uff08\u786e\u4fdd\u67d0\u4e00\u4e2a\u7c7b\u53ea\u6709\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u800c\u4e14\u81ea\u884c\u5b9e\u4f8b\u5316\u5e76\u5411\u6574\u4e2a\u7cfb\u7edf\u63d0\u4f9b\u8fd9\u4e2a\u5b9e\u4f8b\u3002\uff09\u5355\u4f8b\u6a21\u5f0f\u7684\u901a\u7528\u7c7b\u56fe\u5982\u56fe7-2\u6240\u793a\u3002<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Singleton\u7c7b\u79f0\u4e3a\u5355\u4f8b\u7c7b\uff0c\u901a\u8fc7\u4f7f\u7528private\u7684\u6784\u9020\u51fd\u6570\u786e\u4fdd\u4e86\u5728\u4e00\u4e2a\u5e94\u7528\u4e2d\u53ea\u4ea7\u751f\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u5e76\u4e14\u662f\u81ea\u884c\u5b9e\u4f8b\u5316\u7684\uff08\u5728Singleton\u4e2d\u81ea\u5df1\u4f7f\u7528new Singleton()\uff09\u3002\u5355\u4f8b\u6a21\u5f0f\u7684\u901a\u7528\u6e90\u4ee3\u7801\u5982\u4ee3\u7801\u6e05\u53557-3\u6240\u793a\u3002<\/p>\n\n\n\n

public class Singleton {\n    private static final Singleton singleton = new Singleton();\n\n    \/\/\u9650\u5236\u4ea7\u751f\u591a\u4e2a\u5bf9\u8c61\n    private Singleton() {\n    }\n\n    \/\/\u901a\u8fc7\u8be5\u65b9\u6cd5\u83b7\u5f97\u5b9e\u4f8b\u5bf9\u8c61\n    public static Singleton getSingleton() {\n        return singleton;\n    }\n\n    \/\/\u7c7b\u4e2d\u5176\u4ed6\u65b9\u6cd5\uff0c\u5c3d\u91cf\u662fstatic\n    public static void doSomething() {\n    }\n}<\/code><\/pre>\n\n\n\n
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public class Singleton {\n\n    private static Singleton singleton = null;\n\n    \/\/\u9650\u5236\u4ea7\u751f\u591a\u4e2a\u5bf9\u8c61\n    private Singleton() {\n    }\n\n    \/\/\u901a\u8fc7\u8be5\u65b9\u6cd5\u83b7\u5f97\u5b9e\u4f8b\u5bf9\u8c61\n    public static Singleton getSingleton() {\n        if (singleton == null) {\n            singleton = new Singleton();\n        }\n        return singleton;\n    }\n\n    \/\/\u7c7b\u4e2d\u5176\u4ed6\u65b9\u6cd5\uff0c\u5c3d\u91cf\u662fstatic\n    public static void doSomething() {\n    }\n}<\/code><\/pre>\n\n\n\n
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\u516d\u3001\u5355\u4f8b\u6a21\u5f0f\u5728Spring\u4e2d\u7684\u5e94\u7528<\/h2>\n\n\n\n
Spring\u4e3aBean\u63d0\u4f9b\u4e865\u79cdscope\uff0c\u5e38\u7528\u7684\u4e24\u79cd\u4e3asingleton\u4e0eprototype\u3002Spring\u7684singleton\u7684\u4e0e\u5355\u4f8b\u6a21\u5f0f\u662f\u4ec0\u4e48\u5173\u7cfb\uff1f\u666e\u904d\u610f\u4e49\u7684\u5355\u4f8b\u6a21\u5f0f\u662f\u6307\u5728\u4e00\u4e2a\u8fdb\u7a0b\u8303\u56f4\u5185\u4ec5\u6709\u7c7b\u578b\u7684\u4e00\u4e2a\u5b9e\u4f8b\u5b58\u5728\uff0c\u800cSpring\u7684\u5355\u4f8b\uff0c\u662f\u6307\u5728\u4e00\u4e2aSpring\u5bb9\u5668\u4e2d\uff0c\u4ec5\u5b58\u5728\u8be5\u7c7b\u578b\u7684\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u4e5f\u5c31\u662f\u8bf4\u5982\u679c\u8fdb\u7a0b\u4e2d\u5b58\u5728\u591a\u4e2aSpring\u5bb9\u5668\uff0c\u5219\u540c\u6837\u4e00\u4e2a\u7c7b\u4f1a\u5b58\u5728\u591a\u4e2a\u5bf9\u8c61\u5b9e\u4f8b\u3002\u8fd9\u662fSpring\u7684\u5355\u4f8b\u4e0e\u666e\u904d\u610f\u4e49\u4e0a\u7684\u5355\u4f8b\u6a21\u5f0f\u7684\u4e00\u4e2a\u7ec6\u8282\u533a\u522b\u3002<\/p>\n\n\n\n
Spring\u7684Bean\u9ed8\u8ba4scope\u4e3asingleton\uff0c\u662f\u4e3a\u4e86\u80fd\u591f\u964d\u4f4ebean\u7684\u521b\u5efa\u6b21\u6570\uff0c\u63d0\u9ad8\u6548\u7387\u3002\u4f46\u662f\u4e5f\u5bf9bean\u7684\u7f16\u5199\u63d0\u51fa\u4e86\u8981\u6c42\uff0c\u8981\u6c42\u662f\u7ebf\u7a0b\u5b89\u5168\u7684bean\u3002\u8fd9\u91cc\u7684\u7ebf\u7a0b\u5b89\u5168\u5c31\u4e0d\u4ec5\u4ec5\u662f\u5728\u524d\u9762\u4e3e\u4f8b\u7684\u6784\u9020\u7c7b\u578b\u7684\u5bf9\u8c61\u5b9e\u4f8b\u65f6\u7684\u7ebf\u7a0b\u5b89\u5168\uff0c\u800c\u662fbean\u63d0\u4f9b\u7684\u6bcf\u4e2a\u5bf9\u5916\u516c\u5f00\u7684\u65b9\u6cd5\uff0c\u90fd\u8981\u8003\u8651\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\u3002<\/p>\n\n\n\n
\u800c\u5bf9\u4e8e\u5355\u4f8b\u6a21\u5f0f\u56fa\u6709\u7684\u7f3a\u70b9\u95ee\u9898\uff0c\u7ed3\u5408Spring\u5bf9Bean\u58f0\u660e\u5468\u671f\u7684\u63a7\u5236\uff0c\u4ee5\u53ca\u5408\u7406\u7684\u975e\u529f\u80fd\u6027\u7ed3\u6784\u8bbe\u8ba1\uff0c\u80fd\u591f\u5145\u5206\u53d1\u6325\u5355\u4f8b\u6a21\u5f0f\u7684\u4f18\u52bf\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
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<\/p>\n","protected":false},"excerpt":{"rendered":"
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