Java List集合排序实现方法解析

时间:2021-05-20

这篇文章主要介绍了Java List集合排序实现方法解析,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

1.使用 Collections 工具类中的 sort() 方法

参数不同:

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());  }}

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。

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