JsonResourceBodyWriter.java

package sample.jersey.providers;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.emfjson.jackson.module.EMFModule;

import javax.inject.Inject;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

@Provider
@Produces("application/json")
public class JsonResourceBodyWriter implements MessageBodyWriter<Resource> {

	@Inject
	ResourceSet resourceSet;

	@Override
	public boolean isWriteable(Class<?> type, Type genericType, 
			Annotation[] annotations, MediaType mediaType) {
		return type == Resource.class || Resource.class.isAssignableFrom(type);
	}

	@Override
	public long getSize(Resource t, Class<?> type, Type genericType, 
			Annotation[] annotations, MediaType mediaType) {
		return 0;
	}

	@Override
	public void writeTo(Resource resource, Class<?> type, Type genericType,
			Annotation[] annotations, MediaType mediaType,
			MultivaluedMap<String, Object> httpHeaders,
			OutputStream entityStream) throws IOException,
			WebApplicationException {

		ObjectMapper mapper = new ObjectMapper();
		mapper.registerModule(new EMFModule(resourceSet));
		mapper.configure(SerializationFeature.INDENT_OUTPUT, true);

		mapper.writeValue(entityStream, resource);
	}

}