hashset出现了相同的元素？

[加油阿七]

hashset类中的代码为：
package cn.itcast.p2.hashset.demo;

import java.util.HashSet;
import java.util.Iterator;

import cn.itcast.p.bean.Person;

public class Hashsettest {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
HashSet hs=new HashSet();
hs.add(new Person("lisi21",2));
hs.add(new Person("lisi1",4));
hs.add(new Person("lisi21",2));
hs.add(new Person("lisi21",2));
Iterator it=hs.iterator();
while(it.hasNext())
{
Person p=(Person) it.next();
System.out.println(p.getName()+"..."+p.getAge());
}

}

}
person类中的代码为：
package cn.itcast.p.bean;

public class Person extends Object{
private String name;
private int age;

public Person() {
super();
}
public int hashcode()
{
return this.name.hashCode()+age;
}
public boolean equals(Object obj)
{
Person p=(Person) obj;
return this.name.equals(p.name)&&this.age==p.age;
}
public Person(String name, int age) {

this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}

}
运行结果是：
lisi21...2
lisi1...4
lisi21...2
lisi21...2
这是为什么哇？

[鱿鱼ing]

值虽然一样 但是person对象是不一样的 [com.bigdata.runner.Person@4c98385c, com.bigdata.runner.Person@53e25b76, com.bigdata.runner.Person@4cdf35a9, com.bigdata.runner.Person@45fe3ee3]