Question

Is there any way that I can use Jackson JSON Views or something like it, without having to annotate the original bean class? I’m looking for some kind of runtime/dynamic configuration to let me do something similar.

My bean is an @Entity packaged in a JAR that may be shared by multiple projects. I’m trying to avoid touching and re-packaging the shared JAR because of UI changes in the consuming projects.

Ideally I’d like to do something like

jsonViewBuilder = createViewBuilder(View.class);
jsonViewBuilder.addProperty("property1");
jsonViewBuilder.addProperty("property2");

to replace

Bean {
  @JsonView(View.class)
  String property1;

  @JsonView(View.class)
  String property2;
}

Any ideas?

Underlying environment: Spring 3.0, Spring MVC and Glassfish 3.1.1.

Answer 1

How about using the Mix-In feature?

http://wiki.fasterxml.com/JacksonMixInAnnotations

http://www.cowtowncoder.com/blog/archives/2009/08/entry_305.html

---

import org.codehaus.jackson.annotate.JsonAutoDetect.Visibility;
import org.codehaus.jackson.annotate.JsonMethod;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;
import org.codehaus.jackson.map.annotate.JsonView;

public class JacksonFoo
{
  public static void main(String[] args) throws Exception
  {
    ObjectMapper mapper = new ObjectMapper().setVisibility(JsonMethod.FIELD, Visibility.ANY)
        .configure(SerializationConfig.Feature.DEFAULT_VIEW_INCLUSION, false);
    mapper.getSerializationConfig().addMixInAnnotations(Bar.class, BarMixIn.class);
    mapper.setSerializationConfig(mapper.getSerializationConfig().withView(Expose.class));

    System.out.println(mapper.writeValueAsString(new Bar()));
    // output: {"b":"B"}
  }
}

class Bar
{
  String a = "A";
  String b = "B";
}

abstract class BarMixIn
{
  @JsonView(Expose.class)
  String b;
}

// Used only as JsonView marker.  
// Could use any existing class, like Object, instead.  
class Expose {}