ResponseEntity<?>

example.java

	@RequestMapping(value = BASE_PATH + "/{instanceId}", method = RequestMethod.GET)
	public ResponseEntity<?> getServiceInstance(
			@PathVariable("instanceId") String instanceId) {
		
		logger.debug("GET: " + BASE_PATH + "/{instanceId}" 
				+ ", getServiceInstance(), serviceInstanceId = " + instanceId);
		
		ServiceInstance instance = service.getServiceInstance(instanceId);
		
		if (null == instance) { 
			HttpHeaders headers = new HttpHeaders();
			headers.setContentType(MediaType.APPLICATION_JSON);
			return new ResponseEntity<String>("{}", headers, HttpStatus.GONE);
		} 
		logger.debug("ServiceInstance: " + instance.getServiceInstanceId());
		return new ResponseEntity<ServiceInstance>(instance, HttpStatus.OK);
	}