Parse unnamed mappings in JSON using Jackson - json

Question

I have some JSON in the following format that I'm trying to parse with Jackson -
"response":{
"response_inner":{
"a":{"field1":2,"field2":0,"field3":5,"field4":0,"field5":[{"field5_1":"b","field5_2":1},{"field5_1":"c","field5_2":1}]},
"d":{"field1":2,"field2":6,"field3":11,"field4":0,"field5":[{"field5_1":"c","field5_2":1},{"field5_1":"b","field5_2":1}]},
"response_inner_bool":false
}
}
Here "a", "b" etc. are some Strings that can change in each response.
I've created a Java object to represent the 'response_inner' (let's call it ResponseInner) and another to represent the object containing the field?s (let's call this one FieldInfo) but I'm not sure how to parse this using the #JsonCreator and #JsonProperty annotations - ResponseInner objects can contain any number of String -> FieldInfo mappings.
I tried parsing it like this -
public class Response {
private ResponseInner responseInner;
#JsonCreator
public Response(#JsonProperty("response_inner") ResponseInner responseInner) {
this.reponseInner = responseInner;
}
}
public class ResponseInner {
private Map<String, FieldInfo> stringToFieldInfoMap;
private boolean responseInnerBool;
#JsonCreator
public ResponseInner(Map<String, FieldInfo> stringToFieldInfoMap, #JsonProperty("response_inner_bool") boolean responseInnerBool ) {
this.stringToFieldInfoMap = stringToFieldInfoMap;
this.responseInnerBool = responseInnerBool;
}
}
But it complains that Argument #0 of constructor has no property name annotation; must have name when multiple-paramater constructor annotated as Creator. Any suggestions for how to get around this?

Answer 1

You don't seem to be using the stringToFieldInfoMap within ResponseInner anyway. Why do you need to pass it as parameter?
If you do need it in that class, you can simply set it via a setter rather than passing it to constructor.
Alternatively, you could perhaps utilize a third class which deals with that actual mapping of the response, which consumes the Response object (which would in turn consume the ResponseInner object which has had the Map removed from it). This would actually allow you to decouple the mapping logic from the response logic perhaps.
public class MappedResponse {
private Map<String, FieldInfo> stringToFieldInfoMap;
private Response response;
public MappedResponse(Map<String, FieldInfo> stringToFieldInfoMap, Response response) {
this.stringToFieldInfoMap = stringToFieldInfoMap;
this.response = response;
}
}