I use spring-boot as a backend server. It has tens of Action Methods. As usual Some of them contains validation. Actually I use BindingResult and returns validation error for returning Http 400 Status.
#CrossOrigin
#RestController
public class ValidationTestController {
#RequestMapping(value = {"/validation-test", "/validation-test/"}, method = RequestMethod.POST)
#ResponseBody
public ResponseEntity<String> login(#RequestBody #Valid final TestData data, final BindingResult result) {
if (result.hasErrors()) {
return new ResponseEntity<>("Sorry incoming data is not valid!", HttpStatus.BAD_REQUEST);
}
return new ResponseEntity<>("OK!", HttpStatus.OK);
}
private static final class TestData {
#NotNull
private String value;
}
}
My aim is removing follpwing lines:
if (result.hasErrors()) {
return new ResponseEntity<>("Sorry incoming data is not valid!", HttpStatus.BAD_REQUEST);
}
IMHO it's a cross cutting concern like Authentication and Auditing. I want to handle it in a one global ErrorHandler Method. It's possible to throw a CustomValidationException Before executing the method. So I can handle the exception in ErrorController.
Yes, you can centralize the exception handling logic at one place, using #ExceptionHandler which is a ControllerAdvice from Spring.
You can look at here
Related
I'm using Spring to create an API, but I'm having some trouble introducing custom error reporting on (a part of) the validation of the request body.
When parsing/validation errors occur, I want to give a custom response back to the user.
This works well for fields annotated with #Valid along with validators like #javax.validation.constraints.NotNull by using a custom ResponseEntityExceptionHandler annotated with #ControllerAdvice.
It does not work however if an Exception is thrown while parsing the request body (before the validations even run). In that case I get an html error page with status 500 (Server Error)
How can I make sure the exceptions during parsing lead to the same kind of response as the (custom) one I return for validation failures?
My endpoint's code looks like this:
#RequestMapping(value= "/endpoint"
produces = { "application/json" },
consumes = { "application/json" },
method = RequestMethod.POST)
default ResponseEntity<Object> postSomething(#Valid #RequestBody MyRequestBody requestData){
// ...
}
MyRequestBody class looks like this:
#Validated
public class MyRequestData {
#JsonProperty("stringValue")
private String stringValue = null;
#NotNull
#Valid
public String getStringValue() {
return stringValue;
}
// ...
public enum EnumValueEnum {
VALUE_1("value 1"),
VALUE_1("value 2");
private String value;
EnumValueEnum(String value) {
this.value = value;
}
#Override
#JsonValue
public String toString() {
return String.valueOf(value);
}
#JsonCreator
public static EnumValueEnum fromValue(String text) {
if(text == null){
return null;
}
for (EnumValueEnum b : EnumValueEnum.values()){
if (String.valueOf(b.value).equals(text)) {
return b;
}
}
throw new HttpMessageNotReadableException("EnumValueEnum \"" + text + "\" does not exist");
}
}
#JsonProperty("enumValue")
private EnumValueEnum enumValue = null;
}
The custom validation error handling (and reporting) looks like this:
#Order(Ordered.HIGHEST_PRECEDENCE)
#ControllerAdvice
public class MyValidationHandler extends ResponseEntityExceptionHandler {
#Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
// return status(BAD_REQUEST).body(new ValidationResponse(ex.getBindingResult().getFieldErrors()));
}
#Override
protected ResponseEntity<Object> handleHttpMessageNotReadable(HttpMessageNotReadableException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
// return status(BAD_REQUEST).body(new ValidationResponse((JsonMappingException) ex.getCause()));
}
}
In this code, if a user sends a request with an enum value that doesn't exist, an HttpMessageNotReadableException is thrown. I would like to catch that somewhere and replace it with a custom response that is consistent with the other exception handling I do. Where/How can I do that?
I found a solution to my own problem.
You can actually use Spring MVC's normal exception handling:
Annotating a method with #ExceptionHandler will make Spring try to use it for exception handling for the exception type specified (in the annotation's value field or the method's argument). This method can be placed in the controller or even in the ResponseEntityExceptionHandler I use for the other validation response handling.
#ExceptionHandler
public ResponseEntity handle(HttpMessageConversionException e){
// return status(BAD_REQUEST).body(new ValidationResponse((JsonMappingException) e.getCause()));
}
Mind which type of exception you handle:
The catch here was that the exception thrown while parsing is wrapped in (some subtype of) a JsonMappingException which in turn is wrapped again in a HttpMessageConversionException.
e instanceof HttpMessageConversionException
e.getCause() instanceof JsonMappingException
e.getCause().getCause() // == your original exception
The #ExceptionHandler should therefor accept HttpMessageConversionException instead of the originally thrown exception (which in my case was HttpMessageNotReadableException)
It will not work if you write an #ExceptionHandler that only accepts your original Exception!
I have a REST endpoint implemented with Spring MVC #RestController. Sometime, depends on input parameters in my controller I need to send http redirect on client.
Is it possible with Spring MVC #RestController and if so, could you please show an example ?
Add an HttpServletResponse parameter to your Handler Method then call response.sendRedirect("some-url");
Something like:
#RestController
public class FooController {
#RequestMapping("/foo")
void handleFoo(HttpServletResponse response) throws IOException {
response.sendRedirect("some-url");
}
}
To avoid any direct dependency on HttpServletRequest or HttpServletResponse I suggest a "pure Spring" implementation returning a ResponseEntity like this:
HttpHeaders headers = new HttpHeaders();
headers.setLocation(URI.create(newUrl));
return new ResponseEntity<>(headers, HttpStatus.MOVED_PERMANENTLY);
If your method always returns a redirect, use ResponseEntity<Void>, otherwise whatever is returned normally as generic type.
Came across this question and was surprised that no-one mentioned RedirectView. I have just tested it, and you can solve this in a clean 100% spring way with:
#RestController
public class FooController {
#RequestMapping("/foo")
public RedirectView handleFoo() {
return new RedirectView("some-url");
}
}
redirect means http code 302, which means Found in springMVC.
Here is an util method, which could be placed in some kind of BaseController:
protected ResponseEntity found(HttpServletResponse response, String url) throws IOException { // 302, found, redirect,
response.sendRedirect(url);
return null;
}
But sometimes might want to return http code 301 instead, which means moved permanently.
In that case, here is the util method:
protected ResponseEntity movedPermanently(HttpServletResponse response, String url) { // 301, moved permanently,
return ResponseEntity.status(HttpStatus.MOVED_PERMANENTLY).header(HttpHeaders.LOCATION, url).build();
}
As the redirections are usually needed in a not-straightforward path, I think throwing an exception and handling it later is my favourite solution.
Using a ControllerAdvice
#ControllerAdvice
public class RestResponseEntityExceptionHandler
extends ResponseEntityExceptionHandler {
#ExceptionHandler(value = {
NotLoggedInException.class
})
protected ResponseEntity<Object> handleNotLoggedIn(
final NotLoggedInException ex, final WebRequest request
) {
final String bodyOfResponse = ex.getMessage();
final HttpHeaders headers = new HttpHeaders();
headers.add("Location", ex.getRedirectUri());
return handleExceptionInternal(
ex, bodyOfResponse,
headers, HttpStatus.FOUND, request
);
}
}
The exception class in my case:
#Getter
public class NotLoggedInException extends RuntimeException {
private static final long serialVersionUID = -4900004519786666447L;
String redirectUri;
public NotLoggedInException(final String message, final String uri) {
super(message);
redirectUri = uri;
}
}
And I trigger it like this:
if (null == remoteUser)
throw new NotLoggedInException("please log in", LOGIN_URL);
if you #RestController returns an String you can use something like this
return "redirect:/other/controller/";
and this kind of redirect is only for GET request, if you want to use other type of request use HttpServletResponse
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:
when for a solid reason or specific scenario one option must be used mandatorily over the other
If (1) does not matter, what approach is suggested and why.
ResponseEntity is meant to represent the entire HTTP response. You can control anything that goes into it: status code, headers, and body.
#ResponseBody is a marker for the HTTP response body and #ResponseStatus declares the status code of the HTTP response.
#ResponseStatus isn't very flexible. It marks the entire method so you have to be sure that your handler method will always behave the same way. And you still can't set the headers. You'd need the HttpServletResponse.
Basically, ResponseEntity lets you do more.
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.
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);
A proper REST API should have below components in response
Status Code
Response Body
Location to the resource which was altered(for example, if a resource was created, client would be interested to know the url of that location)
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);
}
I am using Spring Boot for a simple REST API and would like to return a correct HTTP statuscode if something fails.
#RequestMapping(value="/rawdata/", method = RequestMethod.PUT)
#ResponseBody
#ResponseStatus( HttpStatus.OK )
public RestModel create(#RequestBody String data) {
// code ommitted..
// how do i return a correct status code if something fails?
}
Being new to Spring and Spring Boot, the basic question is how do i return different status codes when something is ok or fails?
There are several options you can use. Quite good way is to use exceptions and class for handling called #ControllerAdvice:
#ControllerAdvice
class GlobalControllerExceptionHandler {
#ResponseStatus(HttpStatus.CONFLICT) // 409
#ExceptionHandler(DataIntegrityViolationException.class)
public void handleConflict() {
// Nothing to do
}
}
Also you can pass HttpServletResponse to controller method and just set response code:
public RestModel create(#RequestBody String data, HttpServletResponse response) {
// response committed...
response.setStatus(HttpServletResponse.SC_ACCEPTED);
}
Please refer to the this great blog post for details: Exception Handling in Spring MVC
NOTE
In Spring MVC using #ResponseBody annotation is redundant - it's already included in #RestController annotation.
One of the way to do this is you can use ResponseEntity as a return object.
#RequestMapping(value="/rawdata/", method = RequestMethod.PUT)
public ResponseEntity<?> create(#RequestBody String data) {
if(everything_fine) {
return new ResponseEntity<>(RestModel, HttpStatus.OK);
} else {
return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
}
}
A nice way is to use Spring's ResponseStatusException
Rather than returning a ResponseEntityor similar you simply throw the ResponseStatusException from the controller with an HttpStatus and cause, for example:
throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Cause description here");
This results in a response to the client containing the HTTP status:
{
"timestamp": "2020-07-09T04:43:04.695+0000",
"status": 400,
"error": "Bad Request",
"message": "Cause description here",
"path": "/test-api/v1/search"
}
Note: HttpStatus provides many different status codes for your convenience.
In case you want to return a custom defined status code, you can use the ResponseEntity as here:
#RequestMapping(value="/rawdata/", method = RequestMethod.PUT)
public ResponseEntity<?> create(#RequestBody String data) {
int customHttpStatusValue = 499;
Foo foo = bar();
return ResponseEntity.status(customHttpStatusValue).body(foo);
}
The CustomHttpStatusValue could be any integer within or outside of standard HTTP Status Codes.
Try this code:
#RequestMapping(value = "/validate", method = RequestMethod.GET, produces = "application/json")
public ResponseEntity<ErrorBean> validateUser(#QueryParam("jsonInput") final String jsonInput) {
int numberHTTPDesired = 400;
ErrorBean responseBean = new ErrorBean();
responseBean.setError("ERROR");
responseBean.setMensaje("Error in validation!");
return new ResponseEntity<ErrorBean>(responseBean, HttpStatus.valueOf(numberHTTPDesired));
}
There are different ways to return status code,
1 : RestController class should extends BaseRest class, in BaseRest class we can handle exception and return expected error codes.
for example :
#RestController
#RequestMapping
class RestController extends BaseRest{
}
#ControllerAdvice
public class BaseRest {
#ExceptionHandler({Exception.class,...})
#ResponseStatus(value=HttpStatus.INTERNAL_SERVER_ERROR)
public ErrorModel genericError(HttpServletRequest request,
HttpServletResponse response, Exception exception) {
ErrorModel error = new ErrorModel();
resource.addError("error code", exception.getLocalizedMessage());
return error;
}
I think the easiest way is to make return type of your method as
ResponseEntity<WHATEVER YOU WANT TO RETURN>
and for sending any status code, just add return statement as
return ResponseEntity.status(HTTP STATUS).build();
For example, if you want to return a list of books,
public ResponseEntity<List<books>> getBooks(){
List<books> list = this.bookService.getAllBooks();
if(list.size() <= 0)
return ResponseEntity.status(HttpStatus.NOT_FOUND).build();
else
return ResponseEntity.of(Optional.of(list));
}
I'm using Spring 3.1.0.RELEASE. For some reason, in my controller, when I POST my form and return the original screen when an error occurs, model attributes are not getting populated like they do when I invoke the page through a GET method. In my controller I have
#Controller
public class StandardsUploadController {
…
#RequestMapping(value = "/upload")
public String getUploadForm(Model model) {
model.addAttribute(new StandardsUploadItem());
model.addAttribute("gradeList", gradeList);
model.addAttribute("subjectList", subjectList);
return "upload/index";
}
#RequestMapping(value = "/upload", method = RequestMethod.POST)
public ModelAndView processFile(final StandardsUploadItem uploadItem,
final BindingResult result,
final HttpServletRequest request,
final HttpServletResponse response) throws InvalidFormatException, CreateException, NamingException {
stdsUploadValidator.validate(uploadItem, result);
if (!result.hasErrors()) {
try {
…
} catch (IOException e) {
LOG.error(e.getMessage(), e);
e.printStackTrace();
}
} // if
return new ModelAndView("upload/index");
}
What am I doing wrong and how can I correct it?
When you return to the upload/index view from the POST, it is not re-populating the Model, since your code to populate the model is done on the GET.
One potential option is to use the #ModelAttribute annotation in your Controller class
You would have, for example, a method that looks like this for the StandardsUploadItem:
#ModelAttribute("uploadItem")
public StandardsUploadItem getStandardsUploadItem(){
return new StandardsUploadItem();
}
You could then remove the line below from your GET method:
model.addAttribute(new StandardsUploadItem());
Since a method annotated with #ModelAttribute and returning an object will automatically be put in the ModelMap, regardless of which Controller RequestMapping method is activated.
Your method signature for the POST method would contain something like this:
..., #ModelAttribute("uploadItem") StandardsUploadItem uploadItem, ...
You would need to do something similar for the other attributes in your model (gradeList, and subjectList), but since you do not seem to need them on the POST, you could do something like add a Model parameter to your POST method signature, and re-populate that Model before you return the ModelAndView in the error case.