Java：使用Gson解析Json以获取未知字段

Question

I making an parser for json with gson and it based on object model method. My problem is that I have an object on the json where there are some other JsonObjects in it but I don't know there names so I can't use the SerializedName. Also the number of the JsonObjects on the initial object is random. How to iterate the objects from the initial object?

Json style:

"initial_obj": {
     "random_name1": { }
     "random_name50": { }
     "random_name9": { }
}

Answer 1

If the name of fields are not known in advance then convert it into Map<String, Object> using TypeToken

String str = "{\"initial_obj\": {\"random_name1\": { },\"random_name50\": { },\"random_name9\": { }}}";
Type type = new TypeToken<Map<String, Object>>() {}.getType();
Map<String, Object> data = new Gson().fromJson(str, type);
System.out.println(new GsonBuilder().setPrettyPrinting().create().toJson(data));

output:

{
  "initial_obj": {
    "random_name1": {},
    "random_name50": {},
    "random_name9": {}
  }
}