import java.util.Map ;import java.util.HashMap ;class Person{	private String name ;	private int age ;	public Person(String name,int age){		this.name = name ;		this.age = age ;	}	public String toString(){		return "姓名：" + this.name + "；年龄：" + this.age ;	}	public boolean equals(Object obj){		if(this==obj){			return true ;		}		if(!(obj instanceof Person)){			return false ;		}		Person p = (Person)obj ;		if(this.name.equals(p.name)&&this.age==p.age){			return true ;		}else{			return false ;		}	}	public int hashCode(){		return this.name.hashCode() * this.age ;	}};public class HashMapDemo08{	public static void main(String args[]){		Map
    
      map = null ;		map = new HashMap
     
      () ;		map.put(new Person("张三",30),"zhangsan");	// 增加内容		System.out.println(map.get(new Person("张三",30))) ;	}};