Java里面的Comparable接口

实现该接口的类可以对该类的数组进行排序Arrays.sort(list)。也可以对该类的集合进行排序list.sort(null)。

package com.andy.springtransaction.alibaba;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        //数组
        Student[] stu = {new Student(1,"1"),new Student(3,"3"),new Student(2,"2")};
        Arrays.sort(stu);
        for (Student ss : stu){
            System.out.println(ss);
        }
        System.out.println("-------我是分割线-------");
//集合
        List<Student> list  = new ArrayList<>();
        list.add(new Student(1,"1"));
        list.add(new Student(3,"3"));
        list.add(new Student(2,"2"));
        list.sort(null);
// 或 Collections.sort(list);
        for (int i = 0; i < list.size(); i++) {
            System.out.println(list.get(i));
        }
    }
}



//需要进行比较的实体，实现 Comparable 接口
class Student implements Comparable<Student>{

    public Student(){

    }

    public Student(Integer id,String name){
        this.id=id;
        this.name=name;
    }
    private Integer id;

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    @Override
    public int compareTo(Student o) {
        return this.getId() - o.getId();
    }
}