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<Map<String, String>> l = new ArrayList<Map<String, String>>();
Map<String, String> oneMap = new HashMap<String, String>();
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<String, String> twoMap = new HashMap<String, String>();
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<Map<String, String>> twoList = new ArrayList<Map<String, String>>();
Map<String, String> oneMap1 = new HashMap<String, String>();
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<String, String> twoMap2 = new HashMap<String, String>();
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<Map<String, String>> countList = new ArrayList<Map<String, String>>();// 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<String, String> map : countList) {
System.out.println(map);
}
}
}

返回结果： 
{gsName=总部集中处理中心, yybcount=3, type=D, gsId=8000} 
{gsName=南京长江路证券营业部, yybcount=19, type=H, gsId=8008} 
{gsName=南京止马营证券营业部, yybcount=9, type=F, gsId=8008}