java List中相同的数据合并到一起-Toy模板网

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代码

		List<Map<Object,Object>> mapList = new ArrayList<>();
        Map<Object,Object> map = new HashMap<>();
        map.put("C","111");
        map.put("NAME","LB");
        Map<Object,Object> map1 = new HashMap<>();
        map1.put("C","111");
        map1.put("NAME","LA");
        Map<Object,Object> map2 = new HashMap<>();
        map2.put("C","112");
        map2.put("NAME","LC");
        Map<Object,Object> map3 = new HashMap<>();
        map3.put("C","112");
        map3.put("NAME","Lh");
        Map<Object,Object> map4 = new HashMap<>();
        map4.put("C","113");
        map4.put("NAME","LC");
        Map<Object,Object> map5 = new HashMap<>();
        map5.put("C","114");
        map5.put("NAME","LF");
        mapList.add(map);
        mapList.add(map1);
        mapList.add(map2);
        mapList.add(map3);
        mapList.add(map4);
        mapList.add(map5);

        Map<Integer, List<Map<Object,Object>>> mapMap = new HashMap<>();
        for (Map<Object,Object> newMap : mapList){
            List<Map<Object, Object>>  newl = new ArrayList<>();
            // map是否包含此key，若已经包含则添加一个新的数字到对应value集合中
            if (mapMap.containsKey(Integer.valueOf(newMap.get("C").toString()))){
                //mapList.add(Integer.valueOf(newMap.get("C").toString()),newMap);
                mapMap.get(Integer.valueOf(newMap.get("C").toString())).add(newMap);
            }else{
                newl.add(newMap);
                mapMap.put(Integer.valueOf(newMap.get("C").toString()), newl);
            }
        }
        System.out.println(mapMap);