如何将哈希图(字符串，数组列表)转换为3d数组?

Question

我在Hashmap>中的输出是：

House cleaning = [Jack, Maria]
Computer lessons = [Leon, Maria]
Data recovery service = [Leon]
Computer repair = [Jack, Leon]
Handyman = [Jack]

预期输出为

[[["Computer lessons"],["Leon","Maria"]], 
[["Computer repair"],["Jack","Leon"]], 
[["Data recovery service"],["Leon"]], 
[["Handyman"],["Jack"]], 
[["House cleaning"],["Jack","Maria"]]]

顺序无关紧要。

Answer 1

试试这个。

Map<String, List<String>> map = new HashMap<>();
map.put("House cleaning", Arrays.asList("Jack", "Maria"));
map.put("Computer lessons", Arrays.asList("Leon", "Maria"));
map.put("Data recovery service", Arrays.asList("Leon"));
map.put("Computer repair", Arrays.asList("Jack", "Leon"));
map.put("Handyman", Arrays.asList("Jack"));
String[][][] result = map.entrySet().stream()
.map(e -> new String[][] {
new String[] {e.getKey()},
e.getValue().toArray(new String[0])})
.toArray(String[][][]::new);
for (String[][] row : result)
System.out.println(Arrays.deepToString(row));

结果是

[[House cleaning], [Jack, Maria]]
[[Computer lessons], [Leon, Maria]]
[[Data recovery service], [Leon]]
[[Computer repair], [Jack, Leon]]
[[Handyman], [Jack]]