How does @JsonView annotation can be used for nested entities?

Question

I am trying to use @JsonView annotation for my nested entities. To be more clear, assume that, we have 2 entities, each entity have its own view class.

public class JsonViewAddress {
     //some view classes
}


public class Address {
   //fields annotated by JsonViewAddress's classes and @JsonProperty
}

public class JsonViewPerson {
  //some view classes
}

public class Person {

 //some fields (yes annotated with JsonViewPerson classes and @JsonProperty)

 //also assume that this is annotated with any JsonViewPerson's class.
 private Address address;

}

Let's try to achieve this Person class with Json type from response

@Path("hey")
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
public class Resource {


   @GET
   @Path("/stack/overflow")
   @JsonView(value = { /* WHAT SHOULD BE WRITTEN HERE ? */ })
   public Response method() {
       //return Person entity in response
   }
}

@JsonView annotation takes String array, but how should i determine that these written view classes must be work explicitly for each entity they belonged ? I want to see that UserView works for User, AddressView works for Address, shortly.

thanks.

Answer 1

I had a similar problem, it's not exactly your problem but maybe the approach will be usefull for you.

I only use one ViewObject

public class Views {

    public static class Low {
    }

    public static class Medium extends Low {
    }

    public static class High extends Medium {
    }
}

Every time that i have a nested object i need it in the Views.Low View, so i write a Serializer to do this.

public class Serializer extends JsonSerializer<Object> {

    @Override
    public void serialize(Object value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonGenerationException {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.writerWithView(Views.Low.class).writeValue(jgen, value);
    }
} 

Finally in my objects i used like this:

public class Person {

   @JsonView(Views.High.class)
   @JsonSerialize(using = Serializer.class)
   private Address address;

}

The resource:

@Path("hey")
@Produces(MediaType.APPLICATION_JSON)
@Consumes(MediaType.APPLICATION_JSON)
public class Resource {


   @GET
   @Path("/stack/overflow")
   @JsonView(Views.High.class)
   public Response method() {
       //return Person entity in response with address low view
   }

   @GET
   @Path("/stack/overflow")
   @JsonView(Views.Medium.class)
   public Response method() {
       //return Person entity in response with no address
   }

}

You can use this approach to your problem, but if you use different Class Views you have to write a lot of Serializers.