Java中List根据map的某个key去重的代码

   /**
   * 根据map中的某个key 去除List中重复的map
   * @author shijing
   * @param list
   * @param mapKey
   * @return
   */
  public static List<Map<String, Object>> removeRepeatMapByKey(List<Map<String, Object>> 
      list, String mapKey){
    if (CollectionUtils.isNullOrEmpty(list)) return null;
     //把list中的数据转换成msp,去掉同一id值多余数据，保留查找到第一个id值对应的数据
    List<Map<String, Object>> listMap = new ArrayList<>();
    Map<String, Map> msp = new HashMap<>();
    for(int i = list.size()-1 ; i>=0; i--){
      Map map = list.get(i);
      String id = (String)map.get(mapKey);
      map.remove(mapKey);
      msp.put(id, map);
    }
    //把msp再转换成list,就会得到根据某一字段去掉重复的数据的List<Map>
    Set<String> mspKey = msp.keySet();
    for(String key: mspKey){
      Map newMap = msp.get(key);
      newMap.put(mapKey, key);
      listMap.add(newMap);
    }
    return listMap;
  }

public static void main(String[] args) {
    Map<String, Map> msp = new HashMap<String, Map>();
    List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
    List<Map<String, Object>> listMap = new ArrayList<Map<String,Object>>();
    Map<String, Object> map1 = new HashMap<String, Object>();
    map1.put("id", "1123");
    map1.put("name", "张三");
    Map<String, Object> map2 = new HashMap<String, Object>();
    map2.put("id", "2");
    map2.put("name", "李四");
    Map<String, Object> map3 = new HashMap<String, Object>();
    map3.put("id", "1123");
    map3.put("name", "王五");
    Map<String, Object> map4 = new HashMap<String, Object>();
    map4.put("id", "3");
    map4.put("name", "赵六");
    list.add(map1);
    list.add(map2);
    list.add(map3);
    list.add(map4);
    System.out.println("初始数据：" + list.toString());
    System.out.println("去重之后：" + removeRepeatMapByKey(list,"id"));
  }