Jackson JSON Date formatter

//-------------------------------JacksonJsonProvider.java------------------------------------------------------
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.ext.Provider;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.jaxrs.json.JacksonJaxbJsonProvider;

@Provider
@Produces({ MediaType.APPLICATION_JSON })
public class JacksonJsonProvider extends JacksonJaxbJsonProvider {

    public JacksonJsonProvider() {

        ObjectMapper objectMapper = new ObjectMapper()
                .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
                .setDateFormat(new RFC3339DateFormat());

        setMapper(objectMapper);
    }
}

//-------------------------------RFC3339DateFormat.java------------------------------------------------------
import com.fasterxml.jackson.databind.util.ISO8601DateFormat;
import com.fasterxml.jackson.databind.util.ISO8601Utils;

import java.text.FieldPosition;
import java.util.Date;

public class RFC3339DateFormat extends ISO8601DateFormat {

    // Same as ISO8601DateFormat but serializing milliseconds.
    @Override
    public StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition) {
        String value = ISO8601Utils.format(date, true);
        toAppendTo.append(value);
        return toAppendTo;
    }

}

//-------------------------------MyApp.java------------------------------------------------------
import javax.ws.rs.core.Application;

public class MyApp extends Application {

    @Override
    public Set<Class<?>> getClasses() {
        Set<Class<?>> resources = new HashSet<Class<?>>();

        resources.add(MyResource.class);
        resources.add(JacksonJsonProvider.class);

        return resources;
    }

}