import java.util.*;
public class HashSetText {

    public static void main(String [] args)
    {
        HashSet hs = new HashSet();
        hs.add(new Person("a1", 11));  →→ 为什么创建一个对象会自动调用类中的普通方法、创建对象调用其构造方法能理解，能自动调用普通
        hs.add(new Person("a2", 12));            就不能理解了
        hs.add(new Person("a3", 13));
        hs.add(new Person("a2", 12));
        Iterator a = hs.iterator();
        while(a.hasNext())
        {
            System.out.println(a.next());
        }
    }   
}
class Person
{
    private String name;
    private int age;
    public Person(String name, int age)
    {
        this.name = name;
        this.age = age;
    }

    public int hashCode()//重写了hascode 和  equals 方法；
    {
        System.out.println(this.name + "..>><<...hasCode");
        return 100;  
    }
    public boolean equals(Object obj)
    {
        if(!(obj instanceof Person))  
        {
            return false;   
        }
        Person p = (Person) obj;
        System.out.println(this.name +"..equals..."+ p.name);
        
        return this.name.equals(p.name) && this.age == (p.age);
    }
   
}

谢谢！ 听视频讲的是重写的hashCode 和Compare方法

equals 看视频看窜了。。。compare好像是treeSet方法