package com.Set; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.List; public class ArrayListDemo4 { public static void main(String[] args) { List<Person> list = new ArrayList<Person>(); list.add(new Person("jak", 20)); list.add(new Person("roos", 10)); list.add(new Person("marry", 30)); list.add(new Person("jack", 20)); Collections.sort(list, new Comparator<Person>() { @Override public int compare(Person o1, Person o2) { if (o1.getAge() - o2.getAge() > 0) { return 1; } else if (o1.getAge() - o2.getAge() < 0) { return -1; } return o1.getName().compareTo(o2.getName()); } }); for(Person p:list) { System.out.println(p.getAge()+p.getName()); } } } class Person { private String name; private int age; public Person(String name, int age) { this.name = name; this.age = age; } 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; } }