Spring Boot + Thymeleaf - form validation - spring

i have problem with Thymeleaf when validating form. I'm trying to create simple user register form to learn Spring and i'm unfortunately stuck.
Here is my UserForm class
public class UserForm {
#NotEmpty
private String username;
#NotEmpty
private String password;
#NotEmpty
private String passwordConfirm;
\\ Getters and Setters
}
First problem is when I add my custom validator class in initBinder
#Autowired
private UserFormValidator formValidator;
#InitBinder
public void initBinder(WebDataBinder binder) {
binder.setValidator(formValidator);
}
"Default" annotated by #NotEmpty validation stops working. This is exptected behavior?
Second problem is how can I show global reject messages in thymeleaf?
My validator class is like below
public class UserFormValidator implements Validator {
#Autowired
UserService userService;
#Override
public boolean supports(Class<?> clazz) {
return UserForm.class.isAssignableFrom(clazz);
}
#Override
public void validate(Object target, Errors errors) {
UserForm userForm = (UserForm) target;
if(!userForm.getPassword().equals(userForm.getPasswordConfirm())) {
errors.reject("passwords.no.match", "Passwords not match");
}
if(userService.findOneByUsername(userForm.getUsername()).isPresent()) {
errors.reject("user.exist", "User already exists (default)");
}
}
}
and post mapping from controller
#PostMapping("/create")
public String registerUser(#ModelAttribute("form") #Valid final UserForm form, BindingResult bindingResult) {
if(bindingResult.hasErrors()) {
return "newuser";
}
userService.saveUser(form);
return "redirect:/";
}
As "default" validation errors i can show by using exth:if="${#fields.hasErrors('passwordConfirm')}" i have no idea how can i show message for error passwords.no.match or check if this error occured?

By default spring boot uses bean validation to validated form object annotated with #Valid. If you want to use your custom validator and register it through #InitBinder, then bean validation will not take place, this is expected behavior. If you want to bean validation also works with your custom validation you need to do it manually inside your validator class or even in controller.
Here comes your second problem to show password not match error message. Inside your custom validator UserFormValidator.class while rejecting any value you need to use rejectValue() method like below:
#Override
public void validate(Object target, Errors errors) {
UserForm userForm = (UserForm) target;
if(!userForm.getPassword().equals(userForm.getPasswordConfirm())) {
errors.rejectValue("passwordConfirm", "passwords.no.match", "Passwords not match");
}
if(userService.findOneByUsername(userForm.getUsername()).isPresent()) {
errors.rejectValue("username", "user.exist", "User already exists (default)");
}
}
The rejectValue() method is used to add a validation error to the Errors object.
The first parameter identifies which field the error is associated with. The second parameter is an error code which acts a message key for the messages.properties file (or messages_en.properties or messages_fr.properties etc, if these are being used). The third parameter of rejectValue() represents the fallback default message, which is displayed if no matching error code is found in the resource bundle.
Now you can show error messages using th:if="${#fields.hasErrors('passwordConfirm')} inside your form.

Related

Spring Validation Errors for RequestParam

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

Hibernate Validator custom messages key with class name and field name

I've been trying to add custom messages for validation errors for a REST Service managed by Spring MVC within a #Controller class.
The Employee class:
public class Employee {
#NotNull
#NotEmpty
private String company;
...
}
My REST Service:
#ResponseStatus(value = HttpStatus.CREATED)
#RequestMapping(method = RequestMethod.POST)
public void add(#RequestBody #Valid Employee employee) {
employees.add(employee);
}
And the validation errors parses
#ResponseStatus(value = HttpStatus.BAD_REQUEST)
#ExceptionHandler(MethodArgumentNotValidException.class)
public #ResponseBody
List<String> validationExceptions(MethodArgumentNotValidException e) {
List<String> errors = new ArrayList<String>();
for (FieldError error : e.getBindingResult().getFieldErrors()) {
errors.add(error.getDefaultMessage());
}
return errors;
}
So I've put a ValidationMessages.properties on the root of my classpath, and I'm not able to get my custom messages with the following key NotEmpty.employee.company.
I know there are many ways to do this with a ResourceBundle and error.getCode(), or even with the key org.hibernate.validator.constraints.NotEmpty.message, but I'd like have specific messages to specific field of specific objects.
I also don't want to do this with #NotEmpty(message = "NotEmpty.employee.company}"). I want it the simplest.
What should I do?
Have you tried to implement your own
org.springframework.validation.MessageCodesResolver
and then declaring your implementation in the config file:
<mvc:annotation-driven message-codes-resolver="org.example.YourMessageCodesResolverImpl"/>
I'd give it a try, it seems this one is able to build custom error codes like the ones you want:
String[] resolveMessageCodes(String errorCode, String objectName, String field, Class<?> fieldType)
The only and important thing I'm not sure is whether it'll override the error codes generated by the hibernate validators...
I hope it helps (and works).
Cheers,
Chico.

Adding multiple validators using initBinder

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);

JSR 303 set custom validator for cascade #valid

I want to validate a form object which is contained in another form object. I have something like this:
#Controller
public class FormController {
#RequestMapping(method = RequestMethod.POST)
public void process(#ModelAttribute("form") #Valid FormObject formObject,
BindingResult result) {
...
#InitBinder("form")
protected void initBinder(WebDataBinder binder) {
binder.setValidator(customFormValidator);
}
}
public class FormObject {
#Valid
private FormObject2 formObject2;
}
// This is the class that needs to be validated.
public class FormObject2 {
#NotEmpty
private String name;
}
}
The problem I'm having is that I want the object formObject2 to be validated by another custom validator (e.g. "customFormValidator2"), but I can't find how to register it. If I let it like this, the spring validator will validate the second form.
I have tried inside customFormValidator to validate the second form, but then the paths for the errors in the second form are not relative to the first form and I can't display the errors in the jsp page.
I have structured my form object like this, because I might need the second form inside other forms and by doing this I make it more modularized.
Is it possible what I'm trying to do? Do you have better suggestions?
You can use custom validator to validate form Object2 like
public void process(#ModelAttribute("form") #Valid FormObject formObject,
BindingResult result) {
customFormValidator2.validate(formObject.getFormObject2(), result);
}
And remove #Valid to remove JSR validation
public class FormObject {
// #Valid REMOVE THIS
private FormObject2 formObject2;
}
Also you can use path attribute for nested classes like
<form:input path="formObject2.any_property_name">
You can also use same path for errors without any problem.
Check this link for more details.

Spring validation not inside web controllers

I want to use validation not with web controllers. Suppose I have a class Person
public class Person {
private String name;
private String surname;
//getters and setters
...
}
Also I have a validator class:
public class PersonValidator implements Validator {
#Override
public boolean supports(Class<?> clazz) {
return Person.class.equals(clazz);
}
#Override
public void validate(Object target, Errors errors) {
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "name", "name.empty");
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "surname",
"surname.empty");
}
}
How I can use this validator for example in console application? Or validation is only for web application in spring?
You can use the validation tools in a console application. You simply need to call ValidationUtils.invokeValidator(validator, object, errors). Your main concern would be having a suitable Errors instance. You would probably end up using BeanPropertyBindingResult, or subclassing AbstractErrors.
You probably know, but you should consult the Spring reference and javadoc.
Rough guess at untested code:
Person person = new Person();
Errors errors = new BeanPropertyBindingResult(person, "person");
ValidationUtuls.invokeValidator(new PersonValidator(), person, errors);
if (errors.hasErrors()) { ... }
Out of interest, why are you using Spring validation in preference to javax.validation? I've found that it's generally easier to use the javax.validaton/JSR-303 API. Hibernate Validator is the reference implementation and Spring integrates with JSR-303.

Resources