HashSet存储自定义类型元素

/*
必须重写 hashCode 和 toString 方法
*/
package com.itheima.demo02.Set;

import java.util.HashSet;

/*

HashSet 存储自定义类型元素

set 集合报错元素唯一:
    存储的元素 (String,Integer,...Student,Person...), 必须重写 hashCode 方法和 equals 方法

要求:
    同名同年龄的人, 视为同一个人, 只能存储一次 

*/
public class Demo03HashSetSavePerson {

public static void main(String[] args) {
    // 创建 HashSet 集合存储 Person
    HashSet<Person> set = new HashSet<>();
    Person p1 = new Person("小美女",18);
    Person p2 = new Person("小美女",18);
    Person p3 = new Person("小美女",19);
    System.out.println(p1.hashCode());//1967205423
    System.out.println(p2.hashCode());//42121758

    System.out.println(p1==p2);//false
    System.out.println(p1.equals(p2));//false
    set.add(p1);
    set.add(p2);
    set.add(p3);
    System.out.println(set);
}

}
package com.itheima.demo02.Set;

import java.util.Objects;

public class Person {

private String name;
private int age;

public Person() {}

public Person(String name, int age) {
    this.name = name;
    this.age = age;
}

@Override
public boolean equals(Object o) {if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;
    Person person = (Person) o;
    return age == person.age &&
            Objects.equals(name, person.name);
}

@Override
public int hashCode() {return Objects.hash(name, age);
}

@Override
public String toString() {
    return "Person{" +
            "name='" + name + '\'' +
            ", 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;}

}