Jersey Ignore Null Fields with Jackson

Entity.java

@JsonInclude(JsonInclude.Include.NON_NULL)  // Class level
@Document(collection = "Project")
public class Project extends AbstractDocument {
    
    private String name;
    private String serialNumber;
    private Double updatedAt;
    
    @DBRef
    private Customer customer;
    
    @DBRef
    private Universe universe;
  
    // constructor, setter and getter...
  
}

ObjectMapperContextResolver.java

@Provider
public class ObjectMapperContextResolver implements ContextResolver<ObjectMapper> {

    private final ObjectMapper mapper;

    public ObjectMapperContextResolver() {
        mapper = new ObjectMapper();
        // Ignore null value in JSON serialization
        mapper.setSerializationInclusion(Include.NON_NULL);
    }

    @Override
    public ObjectMapper getContext(Class<?> type) {
        return mapper;
    }
}

//Jersey config 
//register(ObjectMapperContextResolver.class);