Returning JAXBElement

HelloWorldController.java

import org.ncpdp.schema.transport.MessageType;
import org.ncpdp.schema.transport.ObjectFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import javax.xml.bind.JAXBElement;

@RestController
public class HelloWorldController {

	@RequestMapping(value = "/api/message", method = RequestMethod.GET)
	public JAXBElement<MessageType> messageType() {
		MessageType type = new MessageType();
		return new ObjectFactory().createMessage(type);
	}
}

MvcConfig.java

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.xml.MarshallingHttpMessageConverter;
import org.springframework.oxm.jaxb.Jaxb2Marshaller;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

import java.util.Arrays;
import java.util.List;

@Configuration
@EnableWebMvc
public class MvcConfig extends WebMvcConfigurerAdapter {

	@Override
	public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
		converters.add(marshallingHttpMessageConverter());
	}

	@Bean
	public MarshallingHttpMessageConverter marshallingHttpMessageConverter() {
		Jaxb2Marshaller jaxb2Marshaller = new Jaxb2Marshaller();
		jaxb2Marshaller.setPackagesToScan(new String[]{"com.ncpdb.schema.transport"});

		MarshallingHttpMessageConverter converter = new MarshallingHttpMessageConverter();
		converter.setMarshaller(jaxb2Marshaller);
		converter.setUnmarshaller(jaxb2Marshaller);
		converter.setSupportedMediaTypes(Arrays.asList(MediaType.APPLICATION_XML));

		return converter;
	}
}