I am working with Spring Framework 4.0.7, together with MVC and Rest
I can work in peace with:
@Controller
ResponseEntity<T>
For example:
@Controller
@RequestMapping("/person")
@Profile("responseentity")
public class PersonRestResponseEntityController {
With the method (just to create)
@RequestMapping(value="/", method=RequestMethod.POST)
public ResponseEntity<Void> createPerson(@RequestBody Person person, UriComponentsBuilder ucb){
logger.info("PersonRestResponseEntityController - createPerson");
if(person==null)
logger.error("person is null!!!");
else
logger.info("{}", person.toString());
personMapRepository.savePerson(person);
HttpHeaders headers = new HttpHeaders();
headers.add("1", "uno");
//http://localhost:8080/spring-utility/person/1
headers.setLocation(ucb.path("/person/{id}").buildAndExpand(person.getId()).toUri());
return new ResponseEntity<>(headers, HttpStatus.CREATED);
}
to return something
@RequestMapping(value="/{id}", method=RequestMethod.GET)
public ResponseEntity<Person> getPerson(@PathVariable Integer id){
logger.info("PersonRestResponseEntityController - getPerson - id: {}", id);
Person person = personMapRepository.findPerson(id);
return new ResponseEntity<>(person, HttpStatus.FOUND);
}
Works fine
I can do the same with:
@RestController
(I know it is the same than @Controller
+ @ResponseBody
) @ResponseStatus
For example:
@RestController
@RequestMapping("/person")
@Profile("restcontroller")
public class PersonRestController {
With the method (just to create)
@RequestMapping(value="/", method=RequestMethod.POST)
@ResponseStatus(HttpStatus.CREATED)
public void createPerson(@RequestBody Person person, HttpServletRequest request, HttpServletResponse response){
logger.info("PersonRestController - createPerson");
if(person==null)
logger.error("person is null!!!");
else
logger.info("{}", person.toString());
personMapRepository.savePerson(person);
response.setHeader("1", "uno");
//http://localhost:8080/spring-utility/person/1
response.setHeader("Location", request.getRequestURL().append(person.getId()).toString());
}
to return something
@RequestMapping(value="/{id}", method=RequestMethod.GET)
@ResponseStatus(HttpStatus.FOUND)
public Person getPerson(@PathVariable Integer id){
logger.info("PersonRestController - getPerson - id: {}", id);
Person person = personMapRepository.findPerson(id);
return person;
}
My questions are:
This question is related to
spring
spring-mvc
spring-3
spring-4
According to official documentation: Creating REST Controllers with the @RestController annotation
@RestController is a stereotype annotation that combines @ResponseBody and @Controller. More than that, it gives more meaning to your Controller and also may carry additional semantics in future releases of the framework.
It seems that it's best to use @RestController
for clarity, but you can also combine it with ResponseEntity
for flexibility when needed (According to official tutorial and the code here and my question to confirm that).
For example:
@RestController
public class MyController {
@GetMapping(path = "/test")
@ResponseStatus(HttpStatus.OK)
public User test() {
User user = new User();
user.setName("Name 1");
return user;
}
}
is the same as:
@RestController
public class MyController {
@GetMapping(path = "/test")
public ResponseEntity<User> test() {
User user = new User();
user.setName("Name 1");
HttpHeaders responseHeaders = new HttpHeaders();
// ...
return new ResponseEntity<>(user, responseHeaders, HttpStatus.OK);
}
}
This way, you can define ResponseEntity
only when needed.
Update
You can use this:
return ResponseEntity.ok().headers(responseHeaders).body(user);
To complete the answer from Sotorios Delimanolis.
It's true that ResponseEntity
gives you more flexibility but in most cases you won't need it and you'll end up with these ResponseEntity
everywhere in your controller thus making it difficult to read and understand.
If you want to handle special cases like errors (Not Found, Conflict, etc.), you can add a HandlerExceptionResolver
to your Spring configuration. So in your code, you just throw a specific exception (NotFoundException
for instance) and decide what to do in your Handler (setting the HTTP status to 404), making the Controller code more clear.
A proper REST API should have below components in response
The main purpose of ResponseEntity was to provide the option 3, rest options could be achieved without ResponseEntity.
So if you want to provide the location of resource then using ResponseEntity would be better else it can be avoided.
Consider an example where a API is modified to provide all the options mentioned
// Step 1 - Without any options provided
@RequestMapping(value="/{id}", method=RequestMethod.GET)
public @ResponseBody Spittle spittleById(@PathVariable long id) {
return spittleRepository.findOne(id);
}
// Step 2- We need to handle exception scenarios, as step 1 only caters happy path.
@ExceptionHandler(SpittleNotFoundException.class)
@ResponseStatus(HttpStatus.NOT_FOUND)
public Error spittleNotFound(SpittleNotFoundException e) {
long spittleId = e.getSpittleId();
return new Error(4, "Spittle [" + spittleId + "] not found");
}
// Step 3 - Now we will alter the service method, **if you want to provide location**
@RequestMapping(
method=RequestMethod.POST
consumes="application/json")
public ResponseEntity<Spittle> saveSpittle(
@RequestBody Spittle spittle,
UriComponentsBuilder ucb) {
Spittle spittle = spittleRepository.save(spittle);
HttpHeaders headers = new HttpHeaders();
URI locationUri =
ucb.path("/spittles/")
.path(String.valueOf(spittle.getId()))
.build()
.toUri();
headers.setLocation(locationUri);
ResponseEntity<Spittle> responseEntity =
new ResponseEntity<Spittle>(
spittle, headers, HttpStatus.CREATED)
return responseEntity;
}
// Step4 - If you are not interested to provide the url location, you can omit ResponseEntity and go with
@RequestMapping(
method=RequestMethod.POST
consumes="application/json")
@ResponseStatus(HttpStatus.CREATED)
public Spittle saveSpittle(@RequestBody Spittle spittle) {
return spittleRepository.save(spittle);
}
Source: Stackoverflow.com