英文:
How to Convert List<Map<String, Object>> to List<Map<String, String>>
问题
我正在从数据库查询中检索结果，格式为 List<Map<String, Object>>，你能否提供建议，如何将其转换为 List<Map<String, String>>。
英文:
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>>.
答案1
得分: 3
迭代列表，依次转换其中的每个映射：
list.stream()
.map(map ->
map.entrySet().stream()
.collect(
Collectors.toMap(
Entry::getKey, e -> e.getValue().toString())))
.collect(Collectors.toList())
英文:
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())
答案2
得分: 1
一个简单的for-each循环遍历列表项及其映射条目即可完成：
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()); // 映射在这里进行
}
newList.add(newMap);
}
在我看来，这是最优解和最易读的解决方案。[tag:java-stream] 并不适用于与字典（映射）一起使用（尽管你总是从中获得一个集合）。
英文:
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 [tag:java-stream] is not suitable much for working with dictionaries (although you always get a collection from it).
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