单例模式

1． Singleton.java

package com.test;

public class Singleton {
	
	private Singleton(){
		
	}
	
	private static Singleton singleton;
	
	public static Singleton getInstance(){
		if(null==singleton){
			singleton=new Singleton();
		}
		return singleton;
	}
}

2． Test.java

package com.test;

public class Test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Singleton singleton1=Singleton.getInstance();
		
		Singleton singleton2=Singleton.getInstance();
		
		
		System.out.println(singleton1==singleton2);
	}

}