import java.util.*;
/*
往hashSet集合中存入自定对象
姓名和年龄相同为同一个人,重复元素。
*/
class HashSetTest
{
public static void sop(Object obj)
{
System.out.println(obj);
}
public static void main(String[] args)
{
HashSet hs = new HashSet();
hs.add(new Person("a1",11));
hs.add(new Person("a2",12));
hs.add(new Person("a3",13));
hs.add(new Person("a2",12));
Iterator it = hs.iterator();
while(it.hasNext())
{
Person p = (Person)it.next();
sop(p.getName()+"::"+p.getAge());
}
}
}
class Person
{
private String name;
private int age;
Person(String name,int age)
{
this.name = name;
this.age = age;
}
public int hashCode()
{
System.out.println(this.name+"....hashCode");
return name.hashCode()+age*37;//*37防止n.hashCode()+age的hashCode相等
//覆写hashCode方法,因为底层自动调用hashCode()和equals()方法
//所以如果hashCode相等就不需要调用equals()
//出去重复
public boolean equals(Object obj)
{
if(!(obj instanceof Person)) //所传元素类型是否Person类型,不是错误
return false;
Person p = (Person)obj;
System.out.println(this.name+"...equals.."+p.name);
return this.name.equals(p.name) && this.age == p.age; //比较内容是否相等
}
public String getName()
{
return name;
}
public int getAge()
{
return age;
}
}