如何转换列表<map<string, object> > 列出<map<string, string> > </map<string,></map<string,>

Question

I am retrieving results from DB Query as List<Map<String, Object>> format, can you suggest, How to convert it to List<Map<String, String>> .

Answer 1

Iterate the list, transforming each of the maps in turn:

list.stream()
    .map(map ->
        map.entrySet().stream()
            .collect(
                Collectors.toMap(
                    Entry::getKey, e -> e.getValue().toString())))
    .collect(Collectors.toList())

Answer 2

A simple for-each iteration over the list items and its map entries does the trick:

List<Map<String, Object>> list = ...
List<Map<String, String>> newList = new ArrayList<>();

for (Map<String, Object> map: list) {
    Map<String, String> newMap = new HashMap<>();
    for (Entry<String, Object> entry: map.entrySet()) {
        newMap.put(entry.getKey(), entry.getValue().toString()); // mapping happens here
    }
    newList.add(newMap);
}

In my opinion, this is the optimal solution and the most readable solution. The java-stream is not suitable much for working with dictionaries (although you always get a collection from it).