Jackson ObjectMapper in RestEasy

JsonConfig.java

import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.annotate.JsonSerialize;

import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.ext.ContextResolver;
import javax.ws.rs.ext.Provider;

@Provider
@Produces({MediaType.APPLICATION_JSON})
public class JsonConfig implements ContextResolver<ObjectMapper> {
    private static final ObjectMapper mapper = new ObjectMapper();
    static {
        mapper.setSerializationInclusion(JsonSerialize.Inclusion.NON_NULL);
    }

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