一、理论

类加载时，创建实例。

二、代码实现

public class HungryManPattern {	//1.将构造函数私有化	private HungryManPattern(){};	//2.类加载时，创建实例	private static HungryManPattern hungryManPattern = new HungryManPattern();	//3.创建获取实例方法	public static HungryManPattern getHungryManPattern(){		return hungryManPattern;	}}

测试

public class Test {	public static void main(String[] args) {		//----------饿汉设计模式------------		HungryManPattern h1 = HungryManPattern.getHungryManPattern();		HungryManPattern h2 = HungryManPattern.getHungryManPattern();		if(h1 == h2){			System.out.println("h1和h2是相同的。");		}else{			System.out.println("h1和h2不是相同的。");		}	}}