Student类：重写hashcode()方法和equals()方法
ackage com.lx.dome;
import java.io.Serializable;
public class Student implements Serializable{
/**
*
*/
private static final long serialVersionUID = 1L;
private Integer stuId;
private Integer stuAge;
private String stuName;
public Integer getStuId() {
return stuId;
}
public void setStuId(Integer stuId) {
this.stuId = stuId;
}
public Integer getStuAge() {
return stuAge;
}
public void setStuAge(Integer stuAge) {
this.stuAge = stuAge;
}
public String getStuName() {
return stuName;
}
public void setStuName(String stuName) {
this.stuName = stuName;
}
@Override
public String toString() {
return "Student [stuId=" + stuId + ", stuAge=" + stuAge + ", stuName=" + stuName + "]";
}
public Student(Integer stuId, Integer stuAge, String stuName) {
super();
this.stuId = stuId;
this.stuAge = stuAge;
this.stuName = stuName;
}
@Override
public int hashCode() {
return stuName.hashCode()+stuAge;
}
@Override
public boolean equals(Object obj) {
if(obj==null) {
return false;
}
if(this==obj) {
return true;
}
Student person=(Student)obj;//强转为Student类型
//指定名字和年龄都相同就认为是同一个对象
if(this.stuName.equals(person.getStuName())&&this.stuAge==person.getStuAge()) {
return true;
}else {
return false;
}
}
}
测试类：
package com.lx.dome;
import java.util.ArrayList;
import java.util.List;
public class StudentTest {
/**
* 实现对象比较，如果名字和年龄都相同，就认为是同一个对象
* 在Person类重写hashCode()和equals(Object obj)方法，并且添加相对应的判断条件逻辑
* @param args
*/
public static void main(String[] args) {
/**
* 在stu1集合中不包含姓名年龄都相同的对象，输出为false
*/
List<Student>stu1=new ArrayList<>();
stu1.add(new Student(1, 22, "matureX"));
stu1.add(new Student(2, 22, "cici"));
stu1.add(new Student(3, 22, "sound"));
stu1.add(new Student(4, 23, "coco"));
System.out.println(stu1.contains(new Student(1, 22, "mature")));
//在stu2集合中包含姓名年龄都相同的对象，输出为true
List<Student>stu2=new ArrayList<>();
stu2.add(new Student(1, 22, "mature"));
stu2.add(new Student(2, 22, "cici"));
stu2.add(new Student(3, 22, "sound"));
stu2.add(new Student(4, 23, "coco"));
System.out.println(stu2.contains(new Student(1, 22, "mature")));
}
}