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!
right now I make custom handler using controlleradvice and is working well. I want to add additional info to the custom validation that "the invoice process has been failed". how do I achieve that ? thank you
You can define you own exception object and uses it to pass the data from the controller method to the exception handler method.
First define an exception as :
public class InvoiceException extends RuntimeException {
private Long invoiceId;
private String additionalInfo;
}
Then in the controller if you check that if violates the related business rules, create an instance of this exception and throw it :
public class InvoiceController {
#PostMapping("/invoice")
public Long processInvoice(InvoiceRequest request){
if(fail) {
throw new InvoiceException(invoiceId, "foobar");
}
}
}
In the #ContorllerAdvice , you can then access these data from the exception instance :
#ControllerAdvice
public class MyExceptionHandler {
#ExceptionHandler(InvoiceException.class)
public ResponseEntity<ErrorMessage> handle(InvoiceException ex) {
}
}
I want to pass org.springframework.validation.Errors to CodeValidator class.
But, since I am not using RequestBody/RequestPart/ModelAttribute, I cannot put Errors in method param after variable.
I use #RequestParam for code variable, and I want to validate that using CodeValidator class that implement org.springframework.validation.Validator.
Here is my code
#RequestMapping(value = "/check-code", method = RequestMethod.POST)
public ResponseEntity<Object> checkCode(#RequestParam("code") String code, Errors errors) {
codeValidator.validate(code, errors);
if(errors.hasErrors()) {
return ResponseEntity.badRequest().body("Errors");
}
return ResponseEntity.ok("");
}
and here error result for my code:
An Errors/BindingResult argument is expected to be declared immediately after the model attribute, the #RequestBody or the #RequestPart arguments to which they apply: public org.springframework.http.ResponseEntity com.example.myapp.controller.CodeController.checkCode(java.lang.String,org.springframework.validation.BindingResult)
what should I do to be able using CodeValidator with #RequestParam?
Updated:
Code for CodeValidator
#Service
public class CodeValidator implements Validator {
#Override
public void validate(Object target, Errors errors) {
String code = ((String) target);
if(code == null || code.isEmpty()) {
errors.rejectValue("code", "", "Please fill in Code.");
}
}
}
Did you create an annotation with your validator?
Otherwise take a look at a small example/tutorial for custom validating with spring: https://www.baeldung.com/spring-mvc-custom-validator
(edit) if you are using spring boot you might need add a MethodValidationPostProcessor bean to your spring config to enable custom valdation for the #requesParam
My controller. Note the custom #Exists annotation:
#RestController
public class ClientApiController {
#RequestMapping(path = "/{client}/someaction", method = RequestMethod.GET)
String handleRequest(#Exists Client client) {
// ...
}
}
The Exists annotation:
/**
* Indicates that a controller request mapping method parametet should not be
* null. This is meant to be used on model types to indicate a required entity.
*/
#Target(ElementType.PARAMETER)
#Retention(RetentionPolicy.RUNTIME)
#Documented
public #interface Exists {}
The converter which converts the String from the path variable into a Client instance:
#Component
public class StringToClient implements Converter<String, Client> {
#Autowired
private ClientDAO clientDAO;
#Override
public Client convert(String source) {
return clientDAO.getClientById(source);
}
}
The ResourceNotFoundException exception used to trigger a 404
#ResponseStatus(value = HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException {
}
My controller method receives the converted Client as desired. If the client id used in the URL matches a client, everything works fine. If the id doesn't match, the client parameter is null empty (uses default constructor) in the handle() controller method.
What I can't get to work now is declarative checking that the Client is not null (i.e. that the id refers to an existing client). If it's null, a ResourceNotFoundException should be thrown. Checking whether the argument is null in the method body and throwing my custom ResourceNotFoundException is easy to do, but repetitive (like this one does). Also, this declarative approach should work for all model classes implementing the interface ModelWithId so it can be used for multiple model types.
I've searched the Spring documentation and I haven't found how to achieve this. I need to insert some processing somewhere after type conversion and before the controller's handleRequest method.
I'm using Spring Boot 1.3.3
After type conversion and before the controller's method there is a validation. You can implement custom validator and raise exception in it. Add new validator to DataBinder, and mark method's parameter as #Validated:
#RestController
public class ClientApiController {
#InitBinder
public void initBinder(DataBinder binder){
binder.addValidators(new Validator() {
#Override
public boolean supports(Class<?> aClass) {
return aClass==Client.class;
}
#Override
public void validate(Object o, Errors errors) {
Client client = (Client)o;
if(client.getId()==null) throw new ResourceNotFoundException();
}
});
}
#RequestMapping(path = "/{client}/someaction", method = RequestMethod.GET)
String handleRequest(#Validated #Exists Client client) {
// ...
}
#RequestMapping(path = "/{client}/anotheraction", method = RequestMethod.GET)
String handleAnotherRequest(#Validated #Exists Client client) {
// ...
}
}
Of course, you can declare validator as separate class, and use it repeatedly in other controllers. Actually, you can raise exception right in your converter, but there is possibility, that you'll need the conversion without exception in other places of your application.
I'm adding a user validator using the initBinder method:
#InitBinder
protected void initBinder(WebDataBinder binder) {
binder.setValidator(new UserValidator());
}
Here is the UserValidator
public class UserValidator implements Validator {
public boolean supports(Class clazz) {
return User.class.equals(clazz);
}
public void validate(Object target, Errors errors) {
User u = (User) target;
// more code here
}
}
The validate method is getting properly called during the controller method call.
#RequestMapping(value = "/makePayment", method = RequestMethod.POST)
public String saveUserInformation(#Valid User user, BindingResult result, Model model){
// saving User here
// Preparing CustomerPayment object for the payment page.
CustomerPayment customerPayment = new CustomerPayment();
customerPayment.setPackageTb(packageTb);
model.addAttribute(customerPayment);
logger.debug("Redirecting to Payment page.");
return "registration/payment";
}
But while returning to the payment screen I'm getting this error:
java.lang.IllegalStateException: Invalid target for Validator [com.validator.UserValidator#710db357]: com.domain.CustomerPayment[ customerPaymentId=null ]
org.springframework.validation.DataBinder.setValidator(DataBinder.java:476)
com.web.UserRegistrationController.initBinder(UserRegistrationController.java:43)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:597)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.initBinder(HandlerMethodInvoker.java:393)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.updateModelAttributes(HandlerMethodInvoker.java:222)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:429)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:414)
This might be because I'm returning a CustomerPayment and there is not validator defined for that.
I'm also not able to add multiple validators in initBinder method.
How can I fix this?
You need to set the value of the #InitBinder annotation to the name of the command you want it to validate. This tells Spring what to apply the binder to; without it, Spring will try to apply it to everything. This is why you're seeing that exception: Spring is trying to apply the binder - with your UserValidator - to a parameter of type CustomerPayment.
In your specific case, it looks like you need something like:
#InitBinder("user")
protected void initBinder(WebDataBinder binder) {
binder.setValidator(new UserValidator());
}
To your second question, as Rigg802 explained, Spring does not support attaching multiple validators to a single command. You can, however, define multiple #InitBinder methods for different commands. So, for example, you could put the following in a single controller and validate your user and payment parameters:
#InitBinder("user")
protected void initUserBinder(WebDataBinder binder) {
binder.setValidator(new UserValidator());
}
#InitBinder("customerPayment")
protected void initPaymentBinder(WebDataBinder binder) {
binder.setValidator(new CustomerPaymentValidator());
}
It's a bit tricky to do, 1 controller has only 1 validator on 1 command object.
you need to create a "Composite Validator" that will get all the validators and run them seperately.
Here is a tutorial that explains how to do it: using multiple validators
You can add multiple validators by iterating over all org.springframework.validation.Validator in an ApplicationContext and set up suitable ones in #InitBinder for each request.
#InitBinder
public void setUpValidators(WebDataBinder webDataBinder) {
for (Validator validator : validators) {
if (validator.supports(webDataBinder.getTarget().getClass())
&& !validator.getClass().getName().contains("org.springframework"))
webDataBinder.addValidators(validator);
}
}
See my project for examples and simple benchmarks. https://github.com/LyashenkoGS/spring-mvc-and-jms-validation-POC/tree/benchamark
I do not see a reason why Spring does not filter out all validators which are not applicable to the current entity by default which forces to use things like CompoundValidator described by #Rigg802.
InitBinder allows you to specify name only which give you some control but not full control over how and when to apply your custom validator. Which from my perspective is not enough.
Another thing you can do is to perform check yourself and add validator to binder only if it is actually necessary, since binder itself has binding context information.
For example if you want to add a new validator which will work with your User object in addition to built-in validators you can write something like this:
#InitBinder
protected void initBinder(WebDataBinder binder) {
Optional.ofNullable(binder.getTarget())
.filter((notNullBinder) -> User.class.equals(notNullBinder.getClass()))
.ifPresent(o -> binder.addValidators(new UserValidator()));
}
There is a simple hack, always return true in supports method, and delegate the class checking to validate. Then basically you can add multiple validator in the initBinder without issue.
#Component
public class MerchantRegisterValidator implements Validator {
#Autowired
private MerchantUserService merchantUserService;
#Autowired
private MerchantCompanyService merchantCompanyService;
#Override
public boolean supports(Class<?> clazz) {
return true; // always true
}
#Override
public void validate(Object target, Errors errors) {
if (!RegisterForm.getClass().equals(target.getClass()))
return; // do checking here.
RegisterForm registerForm = (RegisterForm) target;
MerchantUser merchantUser = merchantUserService.getUserByEmail(registerForm.getUserEmail());
if (merchantUser != null) {
errors.reject("xxx");
}
MerchantCompany merchantCompany = merchantCompanyService.getByRegno(registerForm.getRegno());
if (merchantCompany != null) {
errors.reject("xxx");
}
}
}
Multiple validator on one command is supported with Spring MVC 4.x now. You could use this snippet code:
#InitBinder
protected void initBinder(WebDataBinder binder) {
binder.addValidators(new UserValidator(), new CustomerPaymentValidator());
}
The safest way is to add a generic validator handling that Controller:
#InitBinder
public void initBinder(WebDataBinder binder) {
binder.setValidator(new GenericControllerOneValidator());
}
Then, in the generic validator you can support multiple request body models and based of the instance of the object, you can invoke the appropriate validator:
public class GenericValidator implements Validator {
#Override
public boolean supports(Class<?> aClass) {
return ModelRequestOne.class.equals(aClass)
|| ModelRequestTwo.class.equals(aClass);
}
#Override
public void validate(Object body, Errors errors) {
if (body instanceof ModelRequestOne) {
ValidationUtils.invokeValidator(new ModelRequestOneValidator(), body, errors);
}
if (body instanceof ModelRequestTwo) {
ValidationUtils.invokeValidator(new ModelRequestTwoValidator(), body, errors);
}
}
}
Then you add your custom validations inside for each model validator implementatios. ModeRequestOneValidator and ModeRequestTwoValidator still need to implement the Validator interface of org.springframework.validation
Also, do not forget to use #Valid ModeRequestOne and #Valid ModeRequestTwo inside the controllers method call.
One addition to Annabelle's answer:
If controller has this method parameter and you want to validate that one specifically
#RequestMapping(value = "/users", method = RequestMethod.POST)
public String findUsers(UserRequest request){..}
Then the binding should be lower case of the class name (but just the first letter, and not everything else)
#InitBinder("userRequest")
protected void initUserBinder(WebDataBinder binder) {
binder.setValidator(new YourValidator());
}
Declare request as
(... , Model model,HttpServletRequest request)
and change
model.addAttribute(customerPayment);
to
request.setAttribute("customerPayment",customerPayment);