设计模式之单例模式(2种方法)

 方法一(懒汉式)：

package singleton;

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

package singleton;

public class SingletonTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		
		Singleton singleton = Singleton.getInstance();

	}

}

 

 

方法二(饿汉式)：

package singleton;

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

package singleton;

public class SingletonTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		
		Singleton singleton = Singleton.getInstance();

	}

}