Spring: Map a JSON to String when JSON keys are unknown

Question

Is it possible to map a JSON to a String if its keys are unknown ? Here is a JSON I get for API:

{
  "key1.abc": "Some translation",
  "key2.abc": "Some other translation",
...
}

I tried as follows:

ResponseEntity<String> responseEntity = restTemplate.exchange(uri, HttpMethod.GET, requestEntity, String.class);

but it failed with error:

JsonMappingException: Can not deserialize instance of java.lang.String out of START_OBJECT token

Any ideas ? Thank you

Answer 1

JSONObject json= searchResult.getJSONObject("json");
Iterator keys = json.keys();

while(keys.hasNext()) {
    // loop to get the dynamic key
    String currentDynamicKey = (String)keys.next();

    // get the value of the dynamic key
    JSONObject currentDynamicValue = questionMark.getJSONObject(currentDynamicKey);

    // do something here with the value...
}

Answer 2

Finally, the solution I came to is the following. When I get a response in this form:

{
  "some.translation.key": "traslated text",
  "other.translation.key": "other traslated text"
}

Jackson parser never considers it to be a String but an Object to map to. That's why I had to map the response to a Map. To achieve this, I had to define ParameterizedTypeReferenceof Map type:

ParameterizedTypeReference<Map<String, String>> typeRef = new ParameterizedTypeReference<Map<String, String>>() {};

Then pass it in to the exchange method:

restTemplate.exchange(uri, HttpMethod.GET, requestEntity, typeRef);

where entity is an instance of HttpEntity<Object> class.

Having all the translations saved in the Map, it is easy to get a translation knowing the corresponding key:

map.get("some.translation.key");