奧雷迪爾

package com.rf.xs.list;

import java.util.HashSet;

public class Person {

private String name;

private int 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;

}

public Person(String name, int age) {

this.name = name;

this.age = age;

}

public boolean equals(Object obj){

if(obj instanceof Person){     //判斷obj是不是 Person類型   instanceof:運算符

Person p = (Person)obj;

return this.name.equals(p.name)&& this.age == p.age;

}

return false;

}

   public int HashCode(){

  return 0;

   }

public String  toString(){

return"Person[name="+name+",age="+age+"]";

    }

@Override

public int hashCode() {                    //如果哈希值相同，才回判斷equlas是否相同，如果哈希值不同，不會調用equlas方法。

// TODO Auto-generated method stub

return 0;

}

}

package com.rf.xs.list;
import java.util.HashSet;
import java.util.Iterator;
public class TextHashSet01 {
public static void main(String[] args) {

Person per1 = new Person("q", 18);
Person per2 = new Person("q", 18);
Person per3 = new Person("u", 18);
Person per4 = new Person("w", 28);
Person per5 = new Person("r", 17);
//Person[] p = { per1, per2, per3, per4, per5 };
HashSet<Person> l = new HashSet<Person>();
l.add(per1);
l.add(per2);
l.add(per3);
l.add(per4);
l.add(per5);

HashSet<Person> pers = qc(l);
System.out.println(pers);
}

public static HashSet<Person> qc(HashSet<Person> l){
HashSet<Person> pers = new HashSet<Person>();
Iterator<Person> m = l.iterator();
while (m.hasNext()) {
Person n = m.next();
if (!pers.contains(n)) {
pers.add(n);
}
}
return pers;

}

}