Java中 List《map》把里面map中某个key相同记录的其他key 的 value 合并

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class ListOfMapsMerge {

    public static void main(String[] args) {
        Map<String, Long> map = new HashMap<>();

        map.put("Apple", 2L);
        map.put("Banana", 2L);

        Map<String, Long> map1 = new HashMap<>();

        map1.put("Apple", 2L);
        map1.put("Orange", 2L);

        Map<String, Long> map2 = new HashMap<>();

        map1.put("Banana", 2L);
        map1.put("Guava", 2L);

        List<Map<String, Long>> mapList = new ArrayList<>();

        mapList.add(map);
        mapList.add(map1);