浅学设计模式--单例模式

单例模式很简单就不多介绍了，直接提供代码

1.线程不安全

public class Singleton{

private staitc Singleton singleton = null;

private Singleton(){

}

public Singleton getInstance(){

  if(this.singleton == null){

return new Singleton();

}else{

return singleton ;

}

}

}

2.线程安全

public class Singleton{

private static final Singleton singleton = new Singleton();

private Singleton{

}

public synchronized static Singleton getInstance(){

return singleton ;

}

}