package com.test.interfacetest;

 public class TestComparaTo implements Comparable<TestComparaTo>{

  private int id;

  private String name;

  public int getId() {

   return id;

  }

  public void setId(int id) {

   this.id = id;

  }

  public String getName() {

   return name;

  }

  public void setName(String name) {

   this.name = name;

  }

  @Override

  public int compareTo(TestComparaTo o) {

   return Integer.compare(id, o.getId());

  }

 }

 import java.util.Arrays;

 import java.util.Collections;

 import java.util.List;

 import com.test.interfacetest.TestComparaTo;

 public class MainClass {

  public static void main(String[] args) {

   TestComparaTo testComparaTo = new TestComparaTo();

   testComparaTo.setId(21);

   testComparaTo.setName("钻石王老五");

   TestComparaTo testComparaTo1 = new TestComparaTo();

   testComparaTo1.setId(15);

   testComparaTo1.setName("岛市老八");

   TestComparaTo testComparaTo2 = new TestComparaTo();

   testComparaTo2.setId(19);

   testComparaTo2.setName("芜湖大司马");

   TestComparaTo[] s = {testComparaTo,testComparaTo1,testComparaTo2};

   List<TestComparaTo> asList = Arrays.asList(s);

   System.out.println("排序前集合内容：");

   for(TestComparaTo obj : asList) {

    System.out.println(obj.getName()+"id为："+obj.getId());

   }

   System.out.println("排序前数组内容：");

   for(TestComparaTo obj : s) {

    System.out.println(obj.getName()+"id为："+obj.getId());

   }

   Arrays.sort(s);

   Collections.sort(asList);

   System.out.println("排序后集合内容：");

   for(TestComparaTo obj : asList) {

    System.out.println(obj.getName()+"id为："+obj.getId());

   }

   System.out.println("排序后数组内容：");

   for(TestComparaTo obj : s) {

    System.out.println(obj.getName()+"id为："+obj.getId());

   }

  }

 }

 //以下第一个参数a、b、c、d是TestComparaTo类的实例化对象的数组，对该数组排序

 //根据TestComparaTo类的name属性排序

 Arrays.sort(a,Comparator.comparing(TestComparaTo::getName)); 

 //如果name相同则根据id排序

 Arrays.sort(b,Comparator.comparing(TestComparaTo::getName).thenComparing(TestComparaTo::getId));

 //根据name长度排序

 Arrays.sort(c,Comparator.comparing(TestComparaTo::getName,(a,t)->Integer.compare(a.length(), t.length()))); 

  //根据name长度排序  显然这个比上一个更简单

 Arrays.sort(d,Comparator.comparingInt(a -> a.getName().length()));