合并List<Map<String,String))中的重复数据并对某个字段做累加

package demo;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class mergeData {
    public static void main(String[] args) {
        List> l = new ArrayList>();
        Map oneMap = new HashMap();
        oneMap.put("gsId", "8000");
        oneMap.put("gsName", "总部集中处理中心");
        oneMap.put("type", "D");
        oneMap.put("yybcount", "3");
        l.add(oneMap);
        Map twoMap = new HashMap();
        twoMap.put("gsId", "8008");
        twoMap.put("gsName", "南京长江路证券营业部");
        twoMap.put("type", "H");
        twoMap.put("yybcount", "14");
        l.add(twoMap);

        List> twoList = new ArrayList>();
        Map oneMap1 = new HashMap();
        oneMap1.put("gsId", "8008");
        oneMap1.put("gsName", "南京长江路证券营业部");
        oneMap1.put("type", "H");
        oneMap1.put("yybcount", "5");
        twoList.add(oneMap1);
        Map twoMap2 = new HashMap();
        twoMap2.put("gsId", "8008");
        twoMap2.put("gsName", "南京止马营证券营业部");
        twoMap2.put("type", "F");
        twoMap2.put("yybcount", "9");
        twoList.add(twoMap2);

        l.addAll(twoList);

        List> countList = new ArrayList>();// 用于存放最后的结果
        for (int i = 0; i < l.size(); i++) {
            String gsId = l.get(i).get("gsId");
            String type = l.get(i).get("type");
            int flag = 0;// 0为新增数据，1为增加count
            for (int j = 0; j < countList.size(); j++) {
                String gsId_ = countList.get(j).get("gsId");
                String type_ = countList.get(j).get("type");

                if (gsId.equals(gsId_) && type.equals(type_)) {
                    int sum = Integer.parseInt(l.get(i).get("yybcount"))
                            + Integer.parseInt(countList.get(j).get("yybcount"));
                    countList.get(j).put("yybcount", sum + "");
                    flag = 1;
                    continue;
                }
            }
            if (flag == 0) {
                countList.add(l.get(i));
            }
        }
        for (Map map : countList) {
            System.out.println(map);
        }
    }
}