排序之Map集合根据Map里的value排序

心已赠人 2023-02-09 14:10 22阅读 0赞

[map集合根据value排序][map_value]

import java.util.ArrayList;
    import java.util.Collections;
    import java.util.Comparator;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
     
    public class java_ListMapSort { 
        public static void main(String[] args) { 
            // TODO Auto-generated method stub 
            List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
            Map<String, Object> map1 = new HashMap<String, Object>();
            map1.put("name", "p");
            map1.put("cj", "5");
            Map<String, Object> map2 = new HashMap<String, Object>();
            map2.put("name", "h");
            map2.put("cj", "12");
            Map<String, Object> map3 = new HashMap<String, Object>();
            map3.put("name", "f");
            map3.put("cj", "31");
            list.add(map1);
            list.add(map3);
            list.add(map2);
            //排序前 
            for (Map<String, Object> map : list) { 
                System.out.println(map.get("cj"));
            }
            Collections.sort(list, new Comparator<Map<String, Object>>() { 
                public int compare(Map<String, Object> o1, Map<String, Object> o2) { 
                    Integer name1 = Integer.valueOf(o1.get("cj").toString()) ;//name1是从你list里的第一个name
                    Integer name2 = Integer.valueOf(o2.get("cj").toString()) ; //name2是从你list里的第二个name
                    return name1.compareTo(name2);
                }
            });
            //排序后 
            System.out.println("-------------------");
            for (Map<String, Object> map : list) { 
                System.out.println(map.get("cj"));
            }
        }
    }

--------------------

*  java1.8

Collections.sort(list, (o1,o2)-> {    
                   Integer name1 = Integer.valueOf(o1.get("cj").toString()) ;//name1是从你list里的第一个name
                   Integer name2 = Integer.valueOf(o2.get("cj").toString()) ; //name2是从你list里第二个name
                   return name1.compareTo(name2);
               }
           });

[map_value]: https://www.jianshu.com/p/924a3a48a188