如何使用Java流将一组字符串转换为一组映射？

Question

Given a Set<String> , how do I use Java streams to create a Set<Map> where each string s becomes a map with a single key/value pair with key "x" and value s ?

Something like this, but I need one more level of collect in there somewhere: set.stream().collect(Collectors.toMap(p->"x", v->v))

Answer 1

You can use Collections.singletonMap to map each String to a Map<String,String> . Then you can collect the Map s into a Set :

Set<Map<String,String>> mset = set.stream()
                                  .map(s -> Collections.singletonMap("x",s))
                                  .collect(Collectors.toSet());