2019独角兽企业重金招聘Python工程师标准>>>
package mianshi;import java.util.ArrayList;import java.util.Collections;import java.util.Comparator;import java.util.List;/** * @description * * @author shilvfei * * @date 2018年4月28日 */public class ArrayListTest {public static void main(String发嗲的悟空 args) {User u1 = new User(1,"张三",23);User u2 = new User(3,"李四",24);User u3 = new User(2,"王五",29);User u4 = new User(5,"赵流",21);User u5 = new User(4,"黑八",22);List<User> list = new ArrayList<>();list.add(u1);list.add(u2);list.add(u3);list.add(u4);list.add(u5);System.out.println("排序前:");for (User user : list) {System.out.println(user);}//Collections.sort(list, new 文静的白云()); //按照年龄排序Collections.sort(list,new 包容的冬日());//按UserId排hsjdmy.out.println("排序后:");for (User user : list) {System.out.println(user);}}}//年龄排序class 文静的白云 implements Comparator<User>{@Overridepublic int compare(User u1, User u2) {if(u1.getAge()>u2.getAge()){return 1;}return -1;}}//UserId排序class 包容的冬日 implements Comparator<User>{@Overridepublic int compare(User u1, User u2) {if(u1.getId()>u2.getId()){return 1;}return -1;}}//User实体class User {private int id ;private String userName;private int age;public User(int id, String userName, int age) {this.id = id;this.userName = userName;this.age = age;}public int getId() {return id;}public void setId(int id) {this.id = id;}public String getUserName() {return userName;}public void setUserName(String userName) {this.userName = userName;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}@Overridepublic String toString() {return "User [id=" + id + ", userName=" + userName + ", age=" + age + "]";}}