Bean Validation

For spring mvc to enable form validation, follow the steps below.

Step 1 – LocalValidatorFactoryBean and ResourceBundle

You need to register LocalValidatorFactorBean and resouces bundle implementation to your application context.

<bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
  <property name="basename" value="classpath:messages" /> 
</bean>

<bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean">
  <property name="validationMessageSource" ref="messageSource"/> 
</bean>

Step 2 – Define validator in your mvc:annotation-driven

<mvc:annotation-driven validator="validator" />

<bean id="messageSource" class="">
<bean id="validator" class="">

 .... // code omitted...

Step 3 – Apply annotation validation.

You can find some annotation from this post.

Step 4 – @Valid and BindingResult

The follow code is a sample programming idiom. The important part is annotation @Valid and BindingResult arguments, sequence and both must be present.

@RequestMapping(value = "/form", method = RequestMethod.POST)
public String formPost(@Valid @ModelAttribute("user") User user, 
                       BindingResult result, Model model) {
		
       String view = "resultView";

       if (result.hasErrors()) {
	   view = "formView";
       } else {
	   model.addAttribute("user", user);
       }
       return view;
}

POM

This is the library that required for the job done. I’m using spring platform, therefore i can simply ignore the version of hibernate-validator. Otherwise, you may need to include the version tag to specify the version.

<dependency>
	<groupId>org.hibernate</groupId> 
	<artifactId>hibernate-validator</artifactId>
</dependency>

 Customize error message

@Email
@NotBlank(message = "{error.not.blank}")
private String email;

// code omitted

Properties files 

error.not.blank = Please don't leave blank