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;}@Overridepublic 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;}@Overridepublic int hashCode() { return stuName.hashCode()+stuAge;}@Overridepublic 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 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 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")));}}