List<Map<String, Integer>> 同key的value全部累加合并

public static void main(String[] args){
        List<Map<String,Object>> list1 = new ArrayList<Map<String,Object>>();
        Map<String,Object> map1 = new HashMap<String,Object>();
        Map<String,Object> map2 = new HashMap<String,Object>();
        Map<String,Object> map3 = new HashMap<String,Object>();
        map1.put("张三", new Integer(92));
        map2.put("李四", new Integer(85));
        map3.put("张三", new Integer(90));
        list1.add(map1);
        list1.add(map2);
        list1.add(map3);

        Map<String,Object> mapAll = new HashMap<String,Object>();
        for(Map<String,Object> map:list1){
            for(Map.Entry<String, Object> entry:map.entrySet()){
                String name = entry.getKey();
                Object score = entry.getValue();
                Object scoreAll = mapAll.get(entry.getKey());
                if(scoreAll == null){
                    mapAll.put(name, score);
                }else{
                    scoreAll = new Integer((((Integer)scoreAll).intValue() + ((Integer)score).intValue()));
                    mapAll.put(name, scoreAll);
                }
            }
        }

        for(Map.Entry<String, Object> entry:mapAll.entrySet()){
            //如果需要将map再做list，在这里处理
            System.out.println(entry.getKey() + "," + entry.getValue());
        }

    }

原文地址：https://www.cnblogs.com/hahajava/p/9456479.html