List 根据 元素属性进行排序

`

1package com.utils;
2
3
4import java.util.*;
5
6
7public class UserPaixu  {
8    int age ;
9    String name;
10
11public UserPaixu(int age,String name){
12    this.age = age;
13    this.name = name;
14}
15
16
17
18@Override
19public String toString() {
20    return this.age+" "+this.name;
21}
22
23public static void main(String [] a){
24    UserPaixu u1 = new UserPaixu(1,"z");
25    UserPaixu u2 = new UserPaixu(11,"x");
26    UserPaixu u3 = new UserPaixu(2,"c");
27    UserPaixu u4 = new UserPaixu(33,"v");
28    UserPaixu u5 = new UserPaixu(4,"b");
29    UserPaixu u6 = new UserPaixu(15,"n");
30    List<UserPaixu> list = new ArrayList<UserPaixu>();
31    list.add(u3);
32    list.add(u6);
33    list.add(u1);
34    list.add(u2);
35    list.add(u4);
36    list.add(u5);
37    System.out.println("排序前:  " + list);
38    
39    System.out.println("*************************** ");
40    Collections.sort(list, new Comparator<UserPaixu>() {
41        @Override
42        public int compare(UserPaixu o1, UserPaixu o2) {
43            if (o1.age>o2.age){
44                return 1;
45            }
46            if (o1.age==o2.age){
47                return 0;
48            }
49            return -1;
50        }
51
52    });
53    System.out.println("排序后:  " + list);
54    }
55 }
56    // 输出结果
57    排序前:  [2 c, 15 n, 1 z, 11 x, 33 v, 4 b]
58    *************************** 
59    排序后:  [1 z, 2 c, 4 b, 11 x, 15 n, 33 v]

`