Question

I have JSON response from Facebook, which I don’t want to deserialize into a custom Java object. Mostly because there is no guarantee that their API will stay stable. Once they change it my deserialization will fail for sure.

What I want is to deserialize their JSON data into HashMap<String, Object>, where Object may be a String or a HashMap. In PHP it’s called associative array and it is produced by json_decode() function. Is it possible to do the same in Java?

Answer 1

Certainly. Have a look at Jackson, it can do this easily enough, e.g.

ObjectMapper mapper = new ObjectMapper();
Map<String, Object> userData = mapper.readValue(jsonData, Map.class);

The resulting Map will nest as many levels deep as is required.