NullPointerException while parsing jsonapi object

[jasminb]

NullPointerException while parsing jsonapi object

[jasminb]

Hello,

Reason for the NPE is a fact that you are using readObjectCollection instead of readObject;

readObjectCollection() is expecting a collection of elements to be present:

{
  "data" : [
    {
      "id" : "id",
      "type" : "some-type"
    }
  ]
}

If you switch to readObject method, it should work fine.

I will add proper exception handling in order to communicate these cases accordingly.

[fabricehong]

Hi,

I'm not using readObjectCollection by myself, JSONAPIResponseBodyConverter is doing it.

I'm initializing retrofit this way :

 ObjectMapper objectMapper = new ObjectMapper();

        return new Retrofit.Builder()
                .addConverterFactory(new JSONAPIConverterFactory(objectMapper, Offer.class, OfferVariation.class, Product.class))
                .baseUrl("xxx")
                .client(client)
                .build();

as suggested in the README.md

my Offer object, is something like that:

@Type("offer")
@JsonIgnoreProperties(ignoreUnknown = true)
public class Offer {
    @Id
    private String id;

should I init retrofit differently ?

[jasminb]

Hey,

Do you mind sharing your retrofit service interface?

It looks like you defined a method in your service stub that expects List<YourType> as result and it should be YourType instead.

[fabricehong]

my bad sorry. My interface didn't match the json :

@GET("offers/current")
@Headers("Content-Type:application/json")
Call<List<Offer>> getCurrentDeal(@Query("locale") String locale, @Query("website_identifier") String websiteId);

while it should be

Call<Offer> getCurrentDeal(@Query("locale") String locale, @Query("website_identifier") String websiteId);

I suggest to check for type of the jsonelement, and throw an addequate exception if it's expecting a list while it's not

thanks a lot for your very fast support

[jasminb]

No problem at all, I've already pushed change to develop that validates inputs and throws exceptions in case data being parsed is not matching expected inputs.

[dodos90]

Hi,

I've got a similar issue with the following JSON :
{ "data":[ { "type":"device", "id":4001, "attributes":{ "id":4001, "serial":"0a621724c372cc07", "activationCode":"4000123412341235", "creationDate":1467099796000, "lastCommDate":0 }, "relationships":{ "userDeviceMap":{ "data":[ { "type":"user_device_map", "id":4001 } ] } } } ], "included":[ { "type":"user_device_map", "id":4001, "attributes":{ "id":4001, "active":true, "name":"Device1", "ack":true, "creationDate":1467099796000 } } ] }

When I try to deserialize this JSON, I got the following error :

java.lang.NullPointerException: Attempt to invoke virtual method 'void java.lang.reflect.Field.set(java.lang.Object, java.lang.Object)' on a null object reference at com.github.jasminb.jsonapi.ResourceConverter.setIdValue(ResourceConverter.java:523) at com.github.jasminb.jsonapi.ResourceConverter.readObject(ResourceConverter.java:297) at com.github.jasminb.jsonapi.ResourceConverter.parseRelationship(ResourceConverter.java:483)

This JSON is obtained through a Retrofit client created like this :

this.retrofit = new Retrofit.Builder().baseUrl("xxx) .addConverterFactory(new JSONAPIConverterFactory(new ResourceConverter(Device.class))) .client(new OkHttpClient.Builder().build()) .build();

My Device class looks like this :

@Type("device")
@Parcel
public class Device extends DeviceBeforeCreation implements Model {
@Id String id;
// SOME ATTRIBUTES HERE
@Relationship("userDeviceMap")
private UserDeviceMap userDeviceMap;

// GETTERS AND SETTERS
}

And my "UserDeviceMap" looks like this :

@Type("user_device_map")
@Parcel
@JsonIgnoreProperties(ignoreUnknown = true)
public class UserDeviceMap {
@Id private String id;
public UserDeviceMap() { }

// GETTERS AND SETTERS

}

I don't know if there is something missing from the JSON, or if my client configuration is wrong... I just need to read the data from the "included" block inside my UserDeviceMap object...

Thanks for your help !

EDIT : The Retrofit interface looks like this :

public interface DeviceService { @GET("users/{userId}/boxes/{boxId}/devices") Call<List<Device>> getDevices(@Path("userId") int userId, @Path("boxId") int boxId); }

When I remove the @relationship annotation, I'm able to get the serialization working...

[jasminb]

Hey @dodos90, UserDeviceMap also needs to be registered in ResourceConverter when creating it (besides Device class).

Edit:

It looks like that one device can have many device map entries, so your model should look like this:

@Type("device")
@Parcel
public class Device extends DeviceBeforeCreation implements Model {
@Id String id;
// SOME ATTRIBUTES HERE
@Relationship("userDeviceMap")
private List<UserDeviceMap> userDeviceMap;

[dodos90]

Oh yeah ! I didn't really understand that we need to add the compound classes (like UserDeviceMap) to the ResourceConverter as well. Now it works perfectly, thanks !