public class SingLazy { //类的初始化 不初始化这个对象(延迟加载,用到再创建) private static SingLazy instane; //私有化构造器 private SingLazy(){ //多次调用,抛出异常,防止反射 if(instane!=null){ throw new RuntimeException(); } } //方法同步,销量低 public static synchronized SingLazy gets(){ if(instane==null){ instane=new SingLazy(); } return instane; } }