Java8对List<Map<String,String>>中元素排序降序

import java.util.*;  
  
public class Main {  
    public static void main(String[] args) {  
        List<Map<String, Object>> list = new ArrayList<>();  
        Map<String, Long> map = new HashMap<>();  
        map.put("count", 2L);  
        Map<String, Long> map1 = new HashMap<>();  
        map1.put("count", 3L);  
        list.add(map);  
        list.add(map1);  
  
        // 使用Java 8的Stream API进行排序  
        list.sort((map1, map2) -> {  
            Long count1= (Long) map1.get("count");  
            Long count2 = (Long) map2.get("count");  
            return count2.compareTo(count1); // 降序排序  
        });  
  
        // 输出排序后的结果  
        for (Map<String, Object> m : list) {  
            System.out.println(m);  
        }  
    }  
}

 

升序

retList.sort(map-> (Long) map1.get("count"));

 

降序

 

retList.sort((map1,map2)-> {
                    Long r1 = (Long) map1.get("count");
                    Long r2 = (Long) map1.get("count");
                    return r2.compareTo(r1);//降序
                });

 获取降序结果

            list = list.stream().sorted((map1,map2)->{
                Long r1 = (Long)map1.get("count");
                Long r2 = (Long)map2.get("count");
                return r2.compareTo(r1);
            }).collect(Collectors.toList());