I have a simple SpringMVC controller
#RestController
#Validated
#RequestMapping("/users")
public class UsersController {
#GetMapping
public String getAllUsers(#Valid Filter filter) throws MyCustomServiceException {
[...]
}
}
Since this endpoint has around 20 RequestParam instead of bloating the controller(s) with all the fields I have put them all nicely in a POJO (that actually can be reused in other controllers that needs similar query params filters)
public class UserFilter extends GenericRequestParams {
[...]
#Email(message = "Hey")
private String email;
[...]
}
Here for example I'm using javax.validation.constraints.Email to validate one of the fields.
However when this validation fails instead of throwing the usual org.springframework.web.bind.MethodArgumentNotValidException it throws a org.springframework.validation.BindException
Could someone explain me why ?
So fare I have already dealt with javax.validation.ConstraintViolationException vs org.springframework.web.bind.MethodArgumentNotValidException (and I understood which is thrown when)
but now I also have org.springframework.validation.BindException that come join the party
Related
I have a Get request: \allTopic
It inputs a filterCriteria custom object which contains multiple fields and one of those is an Enum called Role, which is either student or teacher
And there are many more different API calls with different Enums. So I want to create #controllerAdvice that can handle all these.
I need help with
Annotations to put in the Get API controller function header
Annotations to put in the filterCriteria class
What particular exception to handle in #exceptionHandler in #controlleradvice
I have some similar code as per your need, please have a look
#ControllerAdvice
public class ExceptionController {
#ExceptionHandler(value = PageNotFoundException.class)
public String pageNotFoundException(PageNotFoundException exception){
return "error/404";
}
#ExceptionHandler(value = AuthFailedException.class)
public String authFailedException(AuthFailedException exception){
return "error/401";
}
#ExceptionHandler(value = ServerException.class)
public String serverException(ServerException exception){
return "error/500";
}
}
Afterwards, you can throw any of the given type of exception.
please note, you have to create such your exception.
Example:
public class PageNotFoundException extends RuntimeException{
}
I hope, it helps!
I have a not-a-common requirement where I am two different type of consumers for my microservices. One type of consumer is okay with the type-of-response that I am sending them, whereas the other consumer has a requirement where we have to follow their structure (its pretty strict on this).
Lets say I have a StudentController
#RestController
#RequestMapping("/student")
public class StudentController {
#GetMapping("/{name}")
public Student getStudent(#PathVariable String name) {
return Student.builder()
.name(name)
.subjects(List.of("Maths", "English"))
.dateJoined(LocalDate.now().toString())
.build();
}
}
This is alright as one my consumer is accepting my response, where my response looks like this:
{"name":"smit","subjects":["Maths","English"],"dateJoined":"2020-04-26"}
However, the another consumer says that you should sending me the SAME object in a another from something like below:
#RestController
#RequestMapping("/wrapper")
public class WrapperController {
#Autowired
private StudentController studentController;
#GetMapping("/{name}")
public WrapperResponse getStudent(#PathVariable String name){
return WrapperResponse.builder()
.responseTimeStamp(LocalDateTime.now().toString())
.data(studentController.getStudent(name))
.build();
}
}
The below is the output of the above controller.
{"data":{"name":"smit","subjects":["Maths","English"],"dateJoined":"2020-04-26"},"responseTimeStamp":"2020-04-26T01:11:32.986"}
Summary: WrapperController is internally calling StudentController and then wrapping the response in the custom "WrapperResponse" class and then sending that as a response.
Problem: As of now it does solve the problem but I have many such controllers and in my different microservices. So I do not want to rewrite the "WrapperController" for each controller and each microservice.
This is very much opinion-based, but here's how I would refactor this:
Create a Student service (StudentService) that creates the Student,
rather than doing that in the Controller.
Push the code for building a WrapperResponse into the WrapperResponse class itself - either as a static 'factory' method, or as constructor. Have the method take a Student as a parameter.
For each different kind of 'Wrapper' object that you want to supply, have your controller method call the StudentService to get the base Student class, and then construct the Wrapper object by passing the Student to the factory method or constructor of the Wrapper object.
So, your WrapperController might end up looking like this:
#RestController
#RequestMapping("/wrapper")
public class WrapperController {
#Autowired
private StudentService studentService;
#GetMapping("/{name}")
public WrapperResponse getStudent(#PathVariable String name){
return new WrapperResponse(studentService.getStudent(name));
}
}
According to the current doc (5.0.0.RELEASE) Spring Webflux supports validation when working with annotated controllers:
By default if Bean Validation is present on the classpath — e.g.
Hibernate Validator, the LocalValidatorFactoryBean is registered as a
global Validator for use with #Valid and Validated on #Controller
method arguments.
However nothing is said about how to automate it with functional endpoints. In fact, the only example of input processing in the documentation doesn't validate anything:
public Mono<ServerResponse> createPerson(ServerRequest request) {
Mono<Person> person = request.bodyToMono(Person.class);
return ServerResponse.ok().build(repository.savePerson(person));
}
Are we supposed to do this manually or there is some automatic way to do it?
In Spring version 5.0, there is no automatic way to do validation in functional endpoints, and as such validation must be done manually.
Though there are currently no concrete plans to do so, we might add some sort of validation in the future. But even then it will be an explicit method call, and not an automatic mechanism. Overall, the functional endpoint model is designed to be a lot more explicit than the annotation-based model.
As arjen-poutsma said, it seems there is no way of running automated validations on Spring 5 functional endpoints.
Spring documentation is not very clear about this, and it doesn't suggest any approach.
On this Baeldung article, you'll find an idea on how you can run validations using this approach (disclaimer: I'm the writer of the article :) )
In a nutshell, you can follow these steps:
Implement Spring Validators to evaluate your resources
Create an abstract class with the basic procedure that any handler will follow when processing a request, leaving up to the children classes what to do when the data is valid
Make your request handler classes extend this abstract class, implementing this abstract method, stating the body it will be expecting, and what validator needs to be used to validate it
EDIT:
I've been following this related Spring issue, and it seems we now count with official documentation regarding this subject: https://github.com/spring-projects/spring-framework/blob/master/src/docs/asciidoc/web/webflux-functional.adoc#validation
The suggested approach is to use validators as explained in the article.
At the current version(2.0.4.RELEASE) there isn't a way to do automatic validation with handles, however you always could make a manual validation like this:
#Slf4j
#Component
#FieldDefaults(makeFinal = true, level = AccessLevel.PRIVATE)
#RequiredArgsConstructor
public class MyHandlerValidator implements HandlerValidator<MyResource> {
Validator validator;
#Override
public void callValidator(final MyResource fdr) {
final DataBinder binder = new DataBinder(fdr);
binder.setValidator(validator);
binder.validate();
if (binder.getBindingResult().hasErrors()) {
final String reason = binder.getBindingResult().getFieldError().toString();
log.error(reason);
throw new ResponseStatusException(HttpStatus.BAD_REQUEST, reason);
}
}
}
The thing with this, its that the you should throw a WebExchangeBindException like automatic validation does, however i could't create a MethodParameter witch is a dependency to create this exception.
UPDATE:
Spring show us a way to do it, which is similar to my solution, but, not enough in my opinion on documentation
Just to demo some working code. If you need simple validation based on the object annotations like:
#Value
#Builder
#Jacksonized
public class SigninRequest {
#NotBlank(message = "The username is mandatory")
#Email(message = "The username should be valid Email")
String username;
#NotBlank(message = "The password is mandatory")
String password;
}
At the handler you need just one simple additional operator doOnNext:
#Component
#RequiredArgsConstructor
public class AuthHandler {
private final AuthService authService;
private final ObjectValidator validator;
public Mono<ServerResponse> signin(ServerRequest request) {
return ok().body(
request.bodyToMono(SigninRequest.class)
.doOnNext(validator::validate) //<-- just one single line
.flatMap(login -> authService.authenticate(login.getUsername(), login.getPassword())),
AuthResult.class);
}
}
The ObjectValidator is doing actual validation and throws the runtime exception with the 4xx error in case of validation errors:
#Component
#RequiredArgsConstructor
public class ObjectValidator {
private final Validator validator;
public <T> T validate(T object) {
var errors = validator.validate(object);
if (errors.isEmpty()) {
return object;
} else {
String errorDetails = errors.stream().map(er -> er.getMessage()).collect(Collectors.joining(", "));
throw new ObjectValidationException(errorDetails);
}
}
}
And the exception:
#ResponseStatus(code = HttpStatus.UNPROCESSABLE_ENTITY)
public class ObjectValidationException extends RuntimeException {
public ObjectValidationException(String errorDetails) {
super("Please supply the valid data: " + errorDetails);
}
}
If you properly setup global error handling you can keep you handler code clean and reuse the object validator across all your handlers.
I have a class:
public class user{
private String id;
private MultiPartFile file;
**Getters And Setters**
}
And in the Controller:
#PostMapping(value="/upload)
public void upload(User user){
}
In the front end I post data with form-data.I can get the user object.
But when I add #RequestBody and #RequestParam,it can't works.
in my opinion，#RequestParam is used to binding parameter to simple class . when I use #RequestBody ,spring will find HttpMessageConverter to convert http request body to class.But I'm not sure about that.Does anyone can explain to me?
So, I believe we are talking about org.springframework.web.multipart.MultipartFile, which is to be used together with #RequestParam variable. The mechanism is somewhat special in this case.
I had a similar problem, and what I ended up using was org.springframework.web.multipart.commons.CommonsMultipartResolver. From frontend I've constructed multipart request with two parts, in your scenario it could be user (containing just JSON data) and file (containing the file itself), e.g.:
#PostMapping(value="/upload")
public void upload(#RequestParam("user") User user, #RequestParam("file") MultipartFile file){
...
}
But then, you need to configure custom serialization of the User part, which can be done using org.springframework.web.multipart.commons.CommonsMultipartResolver. You can configure it using bean config like this:
#Configuration
public class MappingConfig {
#Order(Integer.MIN_VALUE)
#Bean(name = "multipartResolver")
public CommonsMultipartResolver multipartResolver() {
return new CommonsMultipartResolver();
}
#Bean
public Converter<String, User> stringToUser() {
return new Converter<String, User>() {
#Override
public User convert(String jsonString) {
return new Gson().fromJson(jsonString, User.class);
}
};
}
...
}
Also, as you can see I am using Gson manually, I couldn't find a better way how to do it. Also, it doesn't play with Java 8 lambdas, so it cannot be shortened (because of explicit types are needed for it to work).
I hope that this will at least points you to a right path.
I would like to use both #Post and #Get on the same method like
#GET
#POST
#Path("{mode}")
public void paymentFinish(#PathParam("mode") String mode, String s) {
logger.debug("Enter PayStatus POST");
logger.debug(mode);
}
Even I write like this, I got error. What I want is whatever get or post to the sameurl, the same method works. Is it possible? Now I separate two methods, one for get and one for post.
Unfortunately, only one should be used in order to avoid Jersey exception.
But you could do something like :
#GET
#Path("{mode}")
public void paymentFinish(#PathParam("mode") String mode, String s) {
commonFunction(mode);
}
#POST
#Path("{mode}")
public void paymentFinishPOST(#PathParam("mode") String mode, String s) {
commonFunction(mode);
}
private void commonFunction(String mode)
{
logger.debug("Enter PayStatus POST");
logger.debug(mode);
}
By doing so, if you want to change inner behavior of your functions, you will only have to change one function.
Note that method name in java for get vs post need to be different.
After searching a lot trying to avoid the solution above, I found nothing....
Then I decided to create a custom annotation so I didn't have to waste time duplicating methods.
Here's the github link: Jersey-Gest
It allows you to create GET and Post Methods on a single Annotation by generating a new class from it.
I hope it helps you the same way it helped me :)
Edit:
If for some reason the above link stops working, here's what I did:
Created a compile-time annotation #RestMethod for class methods.
Created a compile-time annotation #RestClass for classes.
Create an AnnotationProcessor which generates a new class with Jersey's corresponding annotations and for each method creates a GET and a POST method which callsback to the original method annotated with #RestClass.
All methods annotated with #RestMethod must be static and contained within a class annotated with #RestClass.
Example (TestService.java):
#RestClass(path = "/wsdl")
public class TestService
{
#RestMethod(path = "/helloGest")
public static String helloGest()
{
return "Hello Gest!";
}
}
Generates something like (TestServiceImpl.java):
#Path("/wsdl")
#Produces("application/xml")
public class TestServiceImpl
{
#GET
#Path("/helloGest")
#Produces(MediaType.APPLICATION_XML)
public String helloGestGet()
{
return TestService.helloGest();
}
#POST
#Path("/helloGest")
#Consumes(MediaType.WILDCARD)
#Produces(MediaType.APPLICATION_XML)
public String helloGestPost()
{
return TestService.helloGest();
}
}