Collections multiple parameter sorting

Sort by job number and time

package com;

import java.util.*;

public class Main {
    public static void main(String[] args){
        List<ConfigVO> list = new ArrayList<ConfigVO>();
        ConfigVO a1 = new ConfigVO();
        a1.setEmployeeNumber("1");
        a1.setActualCheckInTime("2020-05-23");
        ConfigVO a2 = new ConfigVO();
        a2.setEmployeeNumber("2");
        a2.setActualCheckInTime("2020-04-23");
        ConfigVO a3 = new ConfigVO();
        a3.setEmployeeNumber("1");
        a3.setActualCheckInTime("2020-03-23");
        ConfigVO a4 = new ConfigVO();
        a4.setEmployeeNumber("2");
        a4.setActualCheckInTime("2020-06-23");
        list.add(a1);list.add(a2);list.add(a3);list.add(a4);
        Collections.sort(list,new Comparator<ConfigVO>() {
            public int compare(ConfigVO o1,ConfigVO o2) {
                if(o1.getEmployeeNumber().equals(o2.getEmployeeNumber())){
                    return o1.getActualCheckInTime().compareTo(o2.getActualCheckInTime());
                }else{
                    return o1.getEmployeeNumber().compareTo(o2.getEmployeeNumber());
                }
            }
        });
        System.out.println(list.toString());
    }

}

package com;

public class ConfigVO {
    public String employeeNumber;
    public String actualCheckInTime;

    public String getEmployeeNumber() {
        return employeeNumber;
    }

    public void setEmployeeNumber(String employeeNumber) {
        this.employeeNumber = employeeNumber;
    }

    public String getActualCheckInTime() {
        return actualCheckInTime;
    }

    public void setActualCheckInTime(String actualCheckInTime) {
        this.actualCheckInTime = actualCheckInTime;
    }

    @Override
    public String toString() {
        return "ConfigVO{" +
                "employeeNumber='" + employeeNumber + '\'' +
                ", actualCheckInTime='" + actualCheckInTime + '\'' +
                '}';
    }
}