java 将列表<Map> 转换为地图<List>

Question

我低于List<Map>如下

List<Map<String,String>> list =
                                {"key1":"1234"}
                                {"key1":"3422"}
                                {"key1":"7565"}
                                {"key2":"foo"}
                                {"key2":"bar"}
                                {"key3":"xyz"}
                                {"key4":"pqr"}

我需要将其转换为 Map as

                    {"key1":"1234","3422","7565"}
                    {"key2":"foo","bar"}
                    {"key3":"xyz"}
                    {"key4":"pqr"}

Answer 1

Map<String, List<String> myMap = new HashMap();
List<String> tempList = new ArrayList();
for(Map<String, String> entry : myList){
    if (myMap.contains(entry.getKey()))
        tempList = myMap.getValue();
    else
        tempList = new ArrayList();
    
    tempList.add(entry.getValue());
    myMap.put(entry.getKey(), tempList);
}