{"rsdb":{"rid":"377448","subhead":"","postdate":"0","aid":"264124","fid":"97","uid":"1","topic":"1","content":"
\n

\u524d\u8a00<\/h1> \n

\u5728\u4e4b\u524d\u7684 \u8bbe\u8ba1\u6a21\u5f0f - \u5355\u4f8b\u6a21\u5f0f\uff08\u8be6\u89e3\uff09\u770b\u770b\u548c\u4f60\u7406\u89e3\u7684\u662f\u5426\u4e00\u6837\uff1f<\/a> \u4e00\u6587\u4e2d\uff0c\u6211\u4eec\u63d0\u5230\u4e86\u901a\u8fc7Idea<\/code> \u5f00\u53d1\u5de5\u5177\u8fdb\u884c\u591a\u7ebf\u7a0b\u8c03\u8bd5\u3001\u5355\u4f8b\u6a21\u5f0f\u7684\u66b4\u529b\u7834\u574f\u7684\u95ee\u9898\uff1b\u7531\u4e8e\u7bc7\u5e45\u539f\u56e0\uff0c\u73b0\u5728\u5355\u72ec\u5f00\u4e00\u7bc7\u6587\u7ae0\u8fdb\u884c\u6f14\u793a\uff1a\u7ebf\u7a0b\u4e0d\u5b89\u5168\u7684\u5355\u4f8b\u5728\u591a\u7ebf\u7a0b\u60c5\u51b5\u4e0b\u4e3a\u4f55\u88ab\u521b\u5efa\u591a\u4e2a\u3001\u5982\u4f55\u7834\u574f\u5355\u4f8b\u3002<\/p> \n

\n

\u5982\u679c\u8fd8\u4e0d\u77e5\u9053\u5982\u4f55\u4f7f\u7528IDEA\u5de5\u5177\u8fdb\u884c\u7ebf\u7a0b\u6a21\u5f0f\u7684\u8c03\u8bd5\uff0c\u8bf7\u5148\u9605\u8bfb\u6211\u4e4b\u524d\u53d1\u7684\u4e00\u7bc7\u6587\u7ae0\uff1a \u4f60\u4e0d\u77e5\u9053\u7684 IDEA Debug\u8c03\u8bd5\u5c0f\u6280\u5de7<\/a><\/p> \n <\/blockquote> \n

\u4e00\u3001\u7ebf\u7a0b\u4e0d\u5b89\u5168\u7684\u5355\u4f8b\u5728\u591a\u7ebf\u7a0b\u60c5\u51b5\u4e0b\u4e3a\u4f55\u88ab\u521b\u5efa\u591a\u4e2a<\/h1> \n

\u9996\u5148\u56de\u987e\u7b80\u5355\u7ebf\u7a0b\u4e0d\u5b89\u5168\u7684\u61d2\u6c49\u5f0f\u5355\u4f8b\u7684\u4ee3\u7801\u4ee5\u53ca\u6d4b\u8bd5\u7a0b\u5e8f\u4ee3\u7801\uff1a<\/p> \n 

\/**\n * @author eamon.zhang\n * @date 2019-09-30 \u4e0a\u534810:55\n *\/\npublic class LazySimpleSingleton {\n    private LazySimpleSingleton(){}\n    private static LazySimpleSingleton instance = null;\n\n    public static LazySimpleSingleton getInstance(){\n        if (instance == null) {\n            instance = new LazySimpleSingleton();\n        }\n        return instance;\n    }\n}\n\n\/\/ \u6d4b\u8bd5\u7a0b\u5e8f\n@Test\npublic void test() {\n    try {\n        ConcurrentExecutor.execute(() -> {\n            LazySimpleSingleton instance = LazySimpleSingleton.getInstance();\n            System.out.println(Thread.currentThread().getName() + " : " + instance);\n        }, 2, 2);\n    } catch (Exception e) {\n        e.printStackTrace();\n    }\n}<\/code><\/pre> \n 
\u5bf9\u4e8e\u8fd9\u4e2a\u5355\u4f8b\uff0c\u6211\u4eec\u6beb\u65e0\u7591\u95ee\u8ba4\u4e3a\u5b83\u662f\u7ebf\u7a0b\u4e0d\u5b89\u5168\u7684\uff0c\u81f3\u4e8e\u4e3a\u4ec0\u4e48\uff0c\u63a5\u4e0b\u6765\u4f7f\u7528IDEA<\/code>\u5de5\u5177\u7684\u7ebf\u7a0bdebug<\/code>\u6a21\u5f0f\u6765\u76f4\u89c2\u7684\u627e\u51fa\u7b54\u6848\u3002<\/p> \n 
\u5728\u5173\u952e\u4ee3\u7801\u4e0a\u6253\u65ad\u70b9<\/h2> \n 
     \n  
  1. \u5355\u4f8b\u7c7bLazySimpleSingleton<\/code>\u7684if (instance == null)<\/code> \u5904\uff1a<\/li> \n <\/ol> \n 
    <\/p> \n 
       \n  
    1. \u6d4b\u8bd5\u7c7b\uff0c\u591a\u7ebf\u7a0b\u5165\u53e3\u8c03\u7528getInstance()<\/code>\u5904\uff1a<\/li> \n <\/ol> \n 
      <\/p> \n 
      \u5f00\u59cb\u8c03\u8bd5<\/h2> \n 
         \n  
      1. \u542f\u52a8 debug<\/code> \uff0c\u6211\u4eec\u53ef\u4ee5\u5728\u8c03\u8bd5\u7a97\u53e3\u627e\u5230\u6211\u4eec\u542f\u52a8\u7684\u7ebf\u7a0b\uff1a<\/li> \n <\/ol> \n 
        <\/p> \n 
           \n  
        1. \u5c06 pool-1-thread-1<\/code> \u7ebf\u7a0b\u5355\u6b65\u6267\u884c\u5230if (instance == null)<\/code> \u65ad\u70b9\u5904\uff0c\u89c2\u5bdfinstance<\/code>\u503c\u4e3anull<\/code>\uff1b<\/li> \n <\/ol> \n 
          <\/p> \n 
             \n  
          1. \u5c06pool-1-thread-1<\/code>\u6267\u884c\u5230instance = new LazySimpleSingleton();<\/code>\u5904\u7b49\u5f85\u521d\u59cb\u5316\uff1a<\/li> \n <\/ol> \n 
            <\/p> \n 
               \n  
            1. \u5207\u6362\u7ebf\u7a0b pool-1-thread-2<\/code> \u540c\u6837\u5355\u6b65\u6267\u884c\u5230 if (instance == null)<\/code> \u65ad\u70b9\u5904\uff0c\u6b64\u65f6\u89c2\u5bdfinstance<\/code>\u503c\u4e5f\u4e3anull<\/code>\uff08\u8fd9\u5c31\u662f\u6211\u4eec\u5e38\u8bf4\u7684\u4e24\u4e2a\u7ebf\u7a0b\u540c\u65f6\u6267\u884c\u5230\u65ad\u4ee3\u7801\u5904\uff09\uff1a<\/li> \n <\/ol> \n 
              <\/p> \n 
                 \n  
              1. \u540c\u6837\u5c06pool-1-thread-2<\/code>\u6267\u884c\u5230instance = new LazySimpleSingleton();<\/code>\u5904\u7b49\u5f85\u521d\u59cb\u5316\uff1a<\/li> \n <\/ol> \n 
                <\/p> \n 
                   \n  
                1. \u663e\u7136\uff0c\u8fd9\u4e24\u4e2a\u7ebf\u7a0b\u90fd\u6ee1\u8db3if (instance == null)<\/code> \u7684\u6761\u4ef6\uff0c\u90fd\u5e94\u8be5\u5230\u5bf9\u5e94\u7684\u4ee3\u7801\u5757\u4e2d\u6267\u884c\u5b9e\u4f8b\u5316\u64cd\u4f5c\uff0c\u90a3\u4e48\u8fd9\u4e24\u4e2a\u7ebf\u7a0b\u5c31\u4f1a\u5206\u522b\u521d\u59cb\u5316\uff1a<\/li> \n <\/ol> \n 
                  \u7ebf\u7a0b pool-1-thread-1<\/code> \u5b9e\u4f8b\u5316\u540e\uff1a<\/p> \n 
                  <\/p> \n 
                  \u5207\u6362\u7ebf\u7a0b pool-1-thread-2<\/code> \u89c2\u5bdf instance<\/code> \u503c\u5df2\u7ecf\u88ab\u521d\u59cb\u5316\u4e86\uff0c\u4f46\u662f\uff0c\u7ebf\u7a0bpool-1-thread-2<\/code> \u8fd8\u662f\u4f1a\u88ab\u5b9e\u4f8b\u5316\u4e00\u904d\uff1a<\/p> \n 
                  <\/p> \n 
                  \u7ebf\u7a0bpool-1-thread-2<\/code>\u5b9e\u4f8b\u5316\u540e\uff1a<\/p> \n 
                  <\/p> \n 
                  \u5927\u5bb6\u662f\u5426\u4e00\u76ee\u4e86\u7136\u4e86\u5462\uff1f<\/p> \n 
                     \n  
                  1. \u5c06\u4e24\u4e2a\u7ebf\u7a0b\u6267\u884c\u5b8c\uff0c\u770b\u63a7\u5236\u53f0\uff1a<\/li> \n <\/ol> \n 
                    <\/p> \n 
                    \u5927\u5bb6\u53ef\u4ee5\u770b\u5230\uff0c\u867d\u7136\u8f93\u51fa\u6253\u5370\u7684\u5bf9\u8c61\u662f\u540c\u4e00\u4e2a\uff0c\u4f46\u662f\uff0c\u786e\u5b9e\u662f\u521b\u5efa\u4e86\u4e24\u904d\uff0c\u53ea\u4e0d\u8fc7 pool-1-thread-2<\/code> \u5b9e\u4f8b\u5316\u540e\u5c06 pool-1-thread-1<\/code>\u5b9e\u4f8b\u5316\u7684\u5bf9\u8c61\u503c\u7ed9\u8986\u76d6\u4e86\u3002<\/p> \n 
                    \u5f53\u6211\u5c06\u7ebf\u7a0bpool-1-thread-1<\/code>\u548c\u7ebf\u7a0bpool-1-thread-2<\/code>\u540c\u65f6\u6267\u884c\u5230instance = new LazySimpleSingleton();<\/code>\u5904\u7136\u540e\u5148\u8ba9pool-1-thread-1<\/code>\u6267\u884c\u5b8c\u6253\u5370\u540e\uff0c\u518d\u5c06pool-1-thread-2<\/code>\u6267\u884c\u5b9e\u4f8b\u5316\u64cd\u4f5c\uff0c\u5c31\u4f1a\u770b\u5230\u6253\u5370\u7684\u5bf9\u8c61\u4f1a\u662f\u4e0d\u4e00\u6837\u7684\u4e86\uff1a<\/p> \n 
                    <\/p> \n 
                    \u8fd9\u5c31\u662f\u901a\u8fc7\u7ebf\u7a0b\u8c03\u8bd5\u6a21\u5f0f\u624b\u52a8\u63a7\u5236\u7ebf\u7a0b\u6267\u884c\u987a\u5e8f\u6765\u6a21\u62df\u8fd8\u539f\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\uff0c\u7ebf\u7a0b\u4e0d\u5b89\u5168\u7684\u60c5\u51b5\u3002<\/p> \n 
                     \n 
                    \u4e8c\u3001\u6539\u8fdb\u7ebf\u7a0b\u4e0d\u5b89\u5168\u7684\u5355\u4f8b<\/h1> \n 
                    \u6211\u4eec\u660e\u767d\u4e86\u7ebf\u7a0b\u4e0d\u5b89\u5168\u7684\u539f\u56e0\u662f\u4e24\u4e2a\u7ebf\u7a0b\u540c\u65f6\u62ff\u5230\u7684instance<\/code>\u8d44\u6e90\u90fd\u4e3anull<\/code>\uff0c\u4ece\u800c\u90fd\u8fdb\u884c\u5b9e\u4f8b\u5316\u3002\u90a3\u4e48\u6709\u6ca1\u6709\u4ec0\u4e48\u65b9\u6cd5\u80fd\u89e3\u51b3\u5462\uff1f\u5f53\u7136\u6709\uff0c\u7ed9 getInstance()<\/code>\u52a0 \u4e0a synchronized<\/code> \u5173\u952e\u5b57\uff0c\u4f7f\u8fd9\u4e2a\u65b9\u6cd5\u53d8\u6210\u7ebf\u7a0b\u540c\u6b65\u65b9\u6cd5\uff1a<\/p> \n 
                    public class LazySimpleSingleton {\n    private LazySimpleSingleton(){}\n    private static LazySimpleSingleton instance = null;\n\n    public synchronized static LazySimpleSingleton getInstance(){\n        if (instance == null) {\n            instance = new LazySimpleSingleton();\n        }\n        return instance;\n    }\n}<\/code><\/pre> \n 
                    \u5f53\u6211\u4eec\u5c06\u5176\u4e2d\u4e00\u4e2a\u7ebf\u7a0b\u6267\u884c\u5e76\u8c03\u7528 getInstance()<\/code>\u65b9\u6cd5\u65f6\uff0c\u53e6\u4e00\u4e2a\u7ebf\u7a0b\u5728\u8c03\u7528 getInstance()<\/code>\u65b9\u6cd5\uff0c\u7ebf\u7a0b\u7684\u72b6\u6001\u7531 RUNNING<\/code> \u53d8\u6210\u4e86MONITOR<\/code>,\u51fa\u73b0\u963b\u585e\u3002\u76f4\u5230\u7b2c\u4e00\u4e2a\u7ebf\u7a0b\u6267\u884c\u5b8c\uff0c\u7b2c\u4e8c\u4e2a\u7ebf\u7a0b\u624d\u6062\u590d RUNNING<\/code> \u72b6\u6001\u7ee7\u7eed\u8c03\u7528 getInstance()<\/code> \u65b9\u6cd5<\/p> \n 
                    <\/p> \n 
                    \u8fd9\u5c31\u89e3\u51b3\u4e86\u4e4b\u524d\u6240\u8bf4\u7684\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\uff0c\u4f46\u662f\u8fd9\u6837\u5b50\u5728\u7ebf\u7a0b\u6570\u91cf\u6bd4\u8f83\u591a\u60c5\u51b5\u4e0b\uff0c\u5982\u679c CPU<\/code>\u5206\u914d\u538b\u529b\u4e0a\u5347\uff0c\u4f1a\u5bfc\u81f4\u5927\u6279\u91cf\u7ebf\u7a0b\u51fa\u73b0\u963b\u585e\uff0c\u4ece\u800c\u5bfc\u81f4\u7a0b\u5e8f\u8fd0\u884c\u6027\u80fd\u5927\u5e45\u4e0b\u964d\uff1b\u4e3a\u4e86\u89e3\u51b3\u7ebf\u7a0b\u5b89\u5168\u548c\u7a0b\u5e8f\u6027\u80fd\u95ee\u9898\uff0c\u4e8e\u662f\u4e4e\u6709\u4e86\u6211\u4eec\u7684\u53cc\u91cd\u68c0\u67e5\u5f0f\u7684\u5355\u4f8b\u3002\u8fd9\u91cc\u5c31\u4e0d\u518d\u591a\u8bf4\u4e86\u3002<\/p> \n 
                     \n 
                    \u4e09\u3001\u7834\u574f\u5355\u4f8b<\/h1> \n 
                    \u4e00\u822c\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u521b\u5efa\u4f7f\u7528\u997f\u6c49\u5f0f\u5355\u4f8b\u6216\u53cc\u91cd\u68c0\u67e5\u7684\u61d2\u6c49\u5f0f\u5355\u4f8b\u662f\u6ca1\u6709\u95ee\u9898\u7684\uff0c\u4f46\u662f\u5728\u4e00\u5b9a\u60c5\u51b5\u4e0b\uff0c\u4f1a\u53d1\u751f\u5355\u4f8b\u88ab\u7834\u574f\u3002<\/p> \n 
                    \u53cd\u5c04\u7834\u574f\u5355\u4f8b<\/h2> \n 
                    \u5b9e\u9645\u60c5\u51b5\u4e0b\uff0c\u516c\u53f8\u4e00\u4e2a\u7a0b\u5e8f\u5458\u5199\u4e86\u4e00\u4e2a\u5355\u4f8b\uff0c\u4f46\u662f\u53e6\u5916\u4e00\u4e2a\u7a0b\u5e8f\u5458\uff0c\u53ef\u80fd\u6bd4\u8f83\u725b X\uff0c\u5199\u4ee3\u7801\u98ce\u683c\u6709\u70b9\u4e0d\u4e00\u6837\uff0c\u4ed6\u901a\u8fc7\u53cd\u5c04\u6765\u8c03\u7528\u522b\u4eba\u5199\u7684\u63a5\u53e3\uff0c\u8fd9\u5c31\u4f1a\u51fa\u73b0\u6b64\u5355\u4f8b\u5e76\u975e\u5f7c\u5355\u4f8b\u7684\u60c5\u51b5\u3002\u8fd9\u5c31\u7834\u574f\u4e86\u5355\u4f8b\u3002<\/p> \n 
                    \u6f14\u793a<\/h3> \n 
                    \u5728\u6211\u4eec\u5199\u5355\u4f8b\u7684\u65f6\u5019\uff0c\u5927\u5bb6\u6709\u6ca1\u6709\u6ce8\u610f\u5230\u79c1\u6709\u7684\u6784\u9020\u65b9\u6cd5\u524d\u9762\u7684\u4fee\u9970\u7b26\u4ec5\u4e3a private<\/code>\uff0c\u5982\u679c\u6211\u4eec\u4f7f\u7528\u53cd\u5c04\u6765\u8c03\u7528\u5176\u6784\u9020\u65b9\u6cd5\uff0c\u7136\u540e\uff0c\u518d\u8c03\u7528 getInstance()<\/code>\u65b9\u6cd5\uff0c\u5e94\u8be5\u5c31\u4f1a\u6709\u4e24\u4e2a\u4e0d\u540c\u7684\u5b9e\u4f8b\u3002<\/p> \n 
                    \u6211\u4eec\u4ee5\u524d\u9762\u8bf4\u5355\u4f8b\u7684\u6587\u7ae0\u4e2d\u7684 LazyInnerClassSingleton<\/code>\u4e3a\u4f8b\uff0c\u7f16\u5199\u53cd\u5c04\u8c03\u7528\u6d4b\u8bd5\u4ee3\u7801\uff1a<\/p> \n 
                    @Test\npublic void testReflex() {\n    try {\n        \/\/ \u5f88\u65e0\u804a\u7684\u60c5\u51b5\u4e0b\uff0c\u8fdb\u884c\u7834\u574f\n        Class<LazyInnerClassSingleton> clazz = LazyInnerClassSingleton.class;\n        \/\/ \u901a\u8fc7\u53cd\u5c04\u62ff\u5230\u79c1\u6709\u7684\u6784\u9020\u65b9\u6cd5\n        Constructor<LazyInnerClassSingleton> c = clazz.getDeclaredConstructor(null);\n        \/\/ \u8bbe\u7f6e\u8bbf\u95ee\u5c5e\u6027\uff0c\u5f3a\u5236\u8bbf\u95ee\n        c.setAccessible(true);\n\n        \/\/ \u66b4\u529b\u521d\u59cb\u5316\u4e24\u6b21\uff0c\u8fd9\u5c31\u76f8\u5f53\u4e8e\u8c03\u7528\u4e86\u4e24\u6b21\u6784\u9020\u65b9\u6cd5\n        LazyInnerClassSingleton o1 =","orderid":"0","title":"\u8bbe\u8ba1\u6a21\u5f0f - \u5355\u4f8b\u6a21\u5f0f\u4e4b\u591a\u7ebf\u7a0b\u8c03\u8bd5\u4e0e\u7834\u574f\u5355\u4f8b(\u4e00)","smalltitle":"","mid":"0","fname":"\u5206\u6790\u8bbe\u8ba1","special_id":"0","bak_id":"0","info":"0","hits":"474","pages":"5","comments":"0","posttime":"2019-10-10 11:17:42","list":"1570677462","username":"admin","author":"","copyfrom":"","copyfromurl":"","titlecolor":"","fonttype":"0","titleicon":"0","picurl":"https:\/\/www.cppentry.com\/upload_files\/","ispic":"0","yz":"1","yzer":"","yztime":"0","levels":"0","levelstime":"0","keywords":"\u8bbe\u8ba1\u6a21\u5f0f<\/A> \u5355\u4f8b<\/A> \u6a21\u5f0f<\/A> \u7ebf\u7a0b<\/A> \u8c03\u8bd5<\/A> \u7834\u574f<\/A>","jumpurl":"","iframeurl":"","style":"","template":"a:3:{s:4:\"head\";s:0:\"\";s:4:\"foot\";s:0:\"\";s:8:\"bencandy\";s:0:\"\";}","target":"0","ip":"14.17.22.37","lastfid":"0","money":"0","buyuser":"","passwd":"","allowdown":"","allowview":"","editer":"","edittime":"0","begintime":"0","endtime":"0","description":"\u8bbe\u8ba1\u6a21\u5f0f - \u5355\u4f8b\u6a21\u5f0f\u4e4b\u591a\u7ebf\u7a0b\u8c03\u8bd5\u4e0e\u7834\u574f\u5355\u4f8b","lastview":"1714689670","digg_num":"0","digg_time":"0","forbidcomment":"0","ifvote":"0","heart":"","htmlname":"","city_id":"0"},"page":"1"}