线程安全的单例模式

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原创最新推荐文章于 2026-03-02 10:26:48 发布 309 阅读 AI 写同款· GEO 优化 ›

安卓-折叠屏平行视界适配（多厂商兼容与优先级实战）本文详细解析了安卓折叠屏平行视界适配的现状与挑战，重点探讨了多厂商兼容性策略和优先级冲突的实战解决方案。通过对比Google的Embedding方案和国内厂商的EasyGo标准，提供了检测设备支持方案、处理优先级冲突及双方案共存的最佳实践，帮助开发者高效完成折叠屏适配。阅读详情

public class SafeLazyInitialization
 { 
   private static Resource
 resource; 
   public synchronized static Resource
 getInstance() { 
      if (resource
 == null)
          resource
 = new Resource();
      return resource;
    }
}

public class EagerInitialization
 { 
  private static Resource
 resource = new Resource();
  public static Resource
 getResource() { return resource;
 } 
}

//延迟初始化
public class ResourceFactory
 { 
    private static class ResourceHolder
 { 
        public static Resource
 resource = new Resource();
    }
    public static Resource
 getResource() { 
        return ResourceHolder.resource
 ; 
    }
}

public class SingletonDemo
 {
     //注意需要volatile
    private static volatile SingletonDemo instance = null;

    private SingletonDemo() {  }

    public static SingletonDemo
 getInstance() {
        if (instance == null)
 { //二次检查，比直接用独占锁效率高
               synchronized (SingletonDemo
 .class){
                    if (instance
 == null)
 {
                               instance
 = new SingletonDemo
 (); 
                    }
             }
        }
        return instance;
    }
}