Custom JsonDeserializer using inheritance causes StackOverflowError

Question

I'm having an issue with a custom JsonDeserializer. I'm trying to use different implementations of an abstract class depending on the JSON message received by a Rest service call (if the data is an Array use one and if it's a String use another):

@Path("/rest/cipher")
public interface CipherManager {

    @POST
    @Consumes("application/json")
    @Produces("application/json")
    @Path("/encrypt")
    public Response cipher(AbstractCipherRequestBean jsonRequestData);
}

The deserializer looks like this:

public class CipherRequestDeserializer extends JsonDeserializer<AbstractCipherRequestBean> {

@Override
public AbstractCipherRequestBean deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
    ObjectMapper mapper = (ObjectMapper) jp.getCodec();
    ObjectNode root = (ObjectNode) mapper.readTree(jp);
    Class<? extends AbstractCipherRequestBean> abstractCipherRequestBeanClass = null;
    Iterator<Entry<String, JsonNode>> elementsIterator = root.getFields();
    while (elementsIterator.hasNext()) {
        Entry<String, JsonNode> element = elementsIterator.next();
        String name = element.getKey();
        if(name.equals("b64Data")){
            if(element.getValue().isArray()){
                abstractCipherRequestBeanClass = CipherMultRequestBean.class;
            }else{
                abstractCipherRequestBeanClass = CipherRequestBean.class;
            }
        }
    }
    if (abstractCipherRequestBeanClass == null){
        return null;
    }
    return mapper.readValue(root, abstractCipherRequestBeanClass);
}

}

The inheritance is the following:

public class RequestBean {
    protected String b64Data;
    ...
}

@JsonDeserialize(using = CipherRequestDeserializer.class)
public abstract class AbstractCipherRequestBean extends RequestBean{
    ...
}

public class CipherRequestBean extends AbstractCipherRequestBean{
    ...
}

public class CipherMultRequestBean extends AbstractCipherRequestBean {
    private List<String> b64Data;
    ...
}

I believe that since both implementations are inheriting the @JsonDeserialize annotation, each call to mapper.readValue(root, abstractCipherRequestBeanClass) calles the deserialize method again, ending in a StackOverflowError.

Is there a way to avoid this? Since at the end I'm calling the mapper with an actual class, I thought it'd use the default mapper implementation, not the CipherRequestDeserializer one.

Answer 1

I finally found the solution. Just annotating my two subclasses like this was enough:

@JsonDeserialize(as = CipherRequestBean.class)
public class CipherRequestBean extends AbstractCipherRequestBean{
...
}

@JsonDeserialize(as = CipherMultRequestBean.class)
public class CipherMultRequestBean extends AbstractCipherRequestBean {
private List<String> b64Data;
...
}