java concurrency in practice推荐的单例模式

public class ResourceFactory {
    private static class ResourceHolder {
        public static Resource resource = new Resource();
    }

    public static Resource getResource() {
        return ResourceFactory.ResourceHolder.resource;
    }

    static class Resource {
          private Resource(){}; 
    }
}

评论

2 楼 shenhui134 2009-12-02  

恩 对 多谢

1 楼 kingsford 2009-12-02  

后面的那段加上红字部分:

static class Resource {
private Resource(){}; }


防止外部直接调用:
ResourceFactory.Resource res3 = new ResourceFactory.Resource();