import 
java.util.ArrayList;

import 
java.util.Collections;

import 
java.util.Comparator;

import 
java.util.HashMap;

import 
java.util.List;

import 
java.util.Map;
 
/**

* ClassName: Sort 

* @Description: list集合按元素的某一属性排序

* @author ljw

* @date 2018年5月24日

*/

public 
class 
Sort {

public 
static 
void 
main(String[] args) {

List<Map<String, Integer>> list = 
new 
ArrayList<>();

for 
(
int 
i = 
0
; i < 
10
; i++) {

Map<String, Integer> map = 
new 
HashMap<>();

Integer random = (
int
)(Math.random() * 
100
);

map.put(
"random"
, random);

list.add(map);

}

//排序前

System.out.println(
"排序前：" 
+ list);

Collections.sort(list, 
new 
Comparator<Map<String, Integer>>() {

public 
int 
compare(Map<String, Integer> m1, Map<String, Integer> m2) {

//降序

//return m2.get("random").compareTo(m1.get("random"));

//升序

return 
m1.get(
"random"
).compareTo(m2.get(
"random"
));                

}

});

//排序后

System.out.println(
"排序后：" 
+ list);

}

}

排序前：[{random=79}, {random=44}, {random=38}, {random=65}, {random=43}, {random=83}, {random=90}, {random=87}, {random=83}, {random=13}]

排序后：[{random=13}, {random=38}, {random=43}, {random=44}, {random=65}, {random=79}, {random=83}, {random=83}, {random=87}, {random=90}]

ITPub博客

list集合按元素的某一属性排序

最新文章