## JavaList集合排序实现方法解析

2020年02月13日 编程语言 ⁄ 共 2759字 ⁄ 字号 评论关闭

1.使用 Collections 工具类中的 sort() 方法

void sort(List list) 在自定义类User里面实现Comparable<User>接口，并重写抽象方法compareTo(Student o);

void sort(List list, Comparator c) 第二个参数为了省事，可以直接使用匿名内部类

public class User implements Comparable<User>{ private int score; private int age; public User(int score, int age){ super(); this.score = score; this.age = age; } public int getScore() { return score; } public void setScore(int score) { this.score = score; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } @Override public int compareTo(User o) { int i = this.getAge() - o.getAge();//先按照年龄排序 if(i == 0){ return this.score - o.getScore();//如果年龄相等了再用分数进行排序 } return i; } } public static void main(String[] args) { List<User> users = new ArrayList<User>(); users.add(new User(78, 26)); users.add(new User(67, 23)); users.add(new User(34, 56)); users.add(new User(55, 23)); Collections.sort(users); for(User user : users){ System.out.println(user.getScore() + "," + user.getAge()); } }

public class Students { private int age; private int score; public Students(int age, int score){ super(); this.age = age; this.score = score; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public int getScore() { return score; } public void setScore(int score) { this.score = score; } } public static void main(String[] args) { List<Students> students = new ArrayList<Students>(); students.add(new Students(23, 100)); students.add(new Students(27, 98)); students.add(new Students(29, 99)); students.add(new Students(29, 98)); students.add(new Students(22, 89)); Collections.sort(students, new Comparator<Students>() { @Override public int compare(Students o1, Students o2) { int i = o1.getScore() - o2.getScore(); if(i == 0){ return o1.getAge() - o2.getAge(); } return i; } }); for(Students stu : students){ System.out.println("score:" + stu.getScore() + ":age" + stu.getAge()); } }

2.直接使用list.sort()方法，传入实现Comparator接口的实现类的实例，为了省事直接传入匿名内部类

public class Students { private int age; private int score; public Students(int age, int score){ this.age = age; this.score = score; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public int getScore() { return score; } public void setScore(int score) { this.score = score; }}public static void main(String[] args) {　　List<Students> students = new ArrayList<Students>();　　students.add(new Students(23, 100));　　students.add(new Students(27, 98));　　students.add(new Students(29, 99));　　students.add(new Students(29, 98));　　students.add(new Students(22, 89));　　students.sort(new Comparator<Students>() {　　　　@Override　　　　public int compare(Students o1, Students o2) {　　　　　　int i = o1.getScore() - o2.getScore();　　　　　　if (i == 0) {　　　　　　　　return o1.getAge() - o2.getAge();　　　　　　}　　　　　　return i;　　　　}　　});　　for (Students stu : students) {　　　　System.out.println("score:" + stu.getScore() + ":age" + stu.getAge());　　}}