The Java comparator comparator USES sample sharing

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
public class ComparatorTest implements Comparator<stuEntity> {
    
    public static void main(String[] args) {
        List<stuEntity> list = new ArrayList<stuEntity>();
        stuEntity stud1=new stuEntity();
        stud1.setAge(10);
        stud1.setName("abc");
        stuEntity stud2=new stuEntity();
        stud2.setAge(10);
        stud2.setName("bdc");
        stuEntity stud3=new stuEntity();
        stud3.setAge(5);
        stud3.setName("bdd");
        stuEntity stud4=new stuEntity();
        stud4.setAge(30);
        stud4.setName("aad");

        list.add(stud1);
        list.add(stud2);
        list.add(stud3);
        list.add(stud4);

        Collections.sort(list, new ComparatorTest());

        for(stuEntity stud:list){
            System.out.println(stud.getAge()+":"+stud.getName());
        }
    }

    @Override
    public int compare(stuEntity stud1, stuEntity stud2) {
        //Sort by name
        int maxname=stud1.getName().compareTo(stud2.getName());
        if(maxname!=0)
            return maxname;
        //Sort by age
        int maxage=stud1.getAge()-stud2.getAge();
        //if(maxage!=0)
            return maxage;
    }
}

Output:

30:aad
10:abc
10:bdc
5:bdd

The Java Comparator is useful, implementing the compare () callback method on the Comparator interface to make the collation, and then calling collections.sort (list, new ComparatorTest()); I can sort the List, very handy

Note the order in which the returns in the compare () method are used, with the precedence collation first

Entity class:

public class stuEntity {
    private int studentId;//Student id
    private String name;
    private int age;
    private String sex;//gender
    private int roomNumber;//Your room number,
    private String degree;//A degree in
    private int grade;//grade
    private String deviceNumber;//Device number
    private int groupNumber;//group
    private int javaScore;//Java performance
    private int netScore;//The NET result
    public String getDegree() {
        return degree;
    }
    public void setDegree(String degree) {
        this.degree = degree;
    }
    public int getGrade() {
        return grade;
    }
    public void setGrade(int grade) {
        this.grade = grade;
    }
 
    
    public stuEntity(String name, int age, String sex, int roomNumber,
            String deviceNumber, int groupNumber, int javaScore, int netScore) {
        this.name = name;
        this.age = age;
        this.sex = sex;
        this.roomNumber = roomNumber;
        this.deviceNumber = deviceNumber;
        this.groupNumber = groupNumber;
        this.javaScore = javaScore;
        this.netScore = netScore;
    }
    
    public stuEntity() {
    }
    public int getJavaScore() {
        return javaScore;
    }
    public void setJavaScore(int javaScore) {
        this.javaScore = javaScore;
    }
    public int getNetScore() {
        return netScore;
    }
    public void setNetScore(int netScore) {
        this.netScore = netScore;
    }
    
    public int getStudentId() {
        return studentId;
    }
    public void setStudentId(int studentId) {
        this.studentId = studentId;
    }
    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 String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public int getRoomNumber() {
        return roomNumber;
    }
    public void setRoomNumber(int roomNumber) {
        this.roomNumber = roomNumber;
    }
    public String getDeviceNumber() {
        return deviceNumber;
    }
    public void setDeviceNumber(String deviceNumber) {
        this.deviceNumber = deviceNumber;
    }
    public int getGroupNumber() {
        return groupNumber;
    }
    public void setGroupNumber(int groupNumber) {
        this.groupNumber = groupNumber;
    }
}