package testForFun.demo20181109;

import java.util.HashMap;

import java.util.HashSet;

/**

* Created with IntelliJ IDEA

* User:liu

* Date:2018/11/9

* Time:14:27

*/

public class Person {

    private Stringname;

    private  Integerage;

    public Integer getAge() {

    return age;

}

public void setAge(Integer age) {

    this.age = age;

}

/**

    * @return a hash code value for this object.

    * @see Object#equals(Object)

    * @see System#identityHashCode

*/

    @Override

    public int hashCode() {

      return this.name.hashCode()+age*50;

}

/**

    * @param obj the reference object with which to compare.

    * @return {@code true} if this object is the same as the obj

    * argument; {@code false} otherwise.

    * @see #hashCode()

    * @see HashMap

*/

  @Override
   public boolean equals(Object obj) {

    if(!(objinstanceof Person)){

        return false;

    }

    System.out.println("执行的equal方法");

    Person obju = (Person) obj;

    return ( obju.name==this.name&&obju.age==this.age)?true:false;

  }

  @Override

    public String toString() {

    return "Person{" +

    "name='" +name +'\'' +

    ", age=" +age +

    '}';

}

public static void main(String[] args){

    Person a =new Person("张三",18);

    Person b =new Person("张三",18);

    a.setAge(18);

    a.setName("李四");

    HashSet set =new HashSet<>();

    set.add(a);

    set.add(b);

//只有同时重写hashCode和equal方法才能保证自定义的对象在HashSet的唯一性。

    System.out.println("set集合的大小："+set.size());

    System.out.println("a的hashCode: "+a.hashCode()+"， a的内容： "+a.toString());

    System.out.println("b的hasnCode:"+b.hashCode()+"， b的内： "+b.toString());

//-------------------------------------------------------------------//

      Person person =new Person();

      System.out.println(person.toString());

      Person methodtest = person.methodTestThis();

      System.out.println(methodtest);

}

public Person() {

//1，this 在此处表示类的实例，在构造方法中使this关键字表示调用类中的构造方法，this只能在构造方法的第一行。

        this("HELLO",28);

}

public Person(String name, Integer age) {

    this.name = name;

    this.age = age;

}

public String getName() {

    return name;

}

public void setName(String name) {

//2，this 将局部变量的值传递给成员变量

        this.name = name;

}

public Person methodTestThis(){

//3，this 关键字返回这个类。还有一个重大的作用就是返回类的引用

      return this;

}

}