java根据list中的对象某个属性排序

Posted 2021-01-08 魑魅丶魍魉

1、 Collections.sort

 1 public class Test {
 2     public static void main(String[] args) throws Exception {
 3         CityModel city1 = new CityModel();
 4         city1.setCity_code(1);
 5 
 6         CityModel city2 = new CityModel();
 7         city2.setCity_code(1);
 8 
 9         CityModel city3 = new CityModel();
10         city3.setCity_code(1);
11 
12         CityModel city4 = new CityModel();
13         city4.setCity_code(1);
14 
15         CityModel city5 = new CityModel();
16         city5.setCity_code(1);
17 
18         ArrayList<CityModel> list = new ArrayList<>();
19         list.add(city1);
20         list.add(city2);
21         list.add(city3);
22         list.add(city4);
23         list.add(city5);
24 
25         Collections.sort(list, new Comparator<CityModel>(){
26             public int compare(CityModel o1, CityModel o2) {
27                 //按照CityModel的city_code字段进行降序排列
28                 if(o1.getCity_code() < o2.getCity_code()){
29                     return 1;
30                 }
31                 if(o1.getCity_code() == o2.getCity_code()){
32                     return 0;
33                 }
34                 return -1;
35             }
36         });
37 
38         System.out.println(list);
39     }
40 }