小编dQw*_*XcQ的帖子

输入:

public static void main(String[] args) {

    final String key = "some key";
    final String value = "some value";

    Map<String, String> map1 = new HashMap<String, String>(){{put(key, value);}};
    System.out.println(new Gson().toJson(map1) + " " + map1.get(key));

    Map<String, String> map2 = new HashMap<>();
    map2.put(key, value);
    System.out.println(new Gson().toJson(map2) + " " + map2.get(key));
}

输出:

null some value
{"some key":"some value"} some value

Process finished with exit code 0