SpringMVC 3 + JSR 303 validation with Hibernate validator 4.x

Spring provides many ways to validate an object, I have posted an article about Spring's Validator Interface, now I will show you how to validate an object with JSR 303 in Spring 3.x by using Hibernate validator.

1. Import Hibernate Validator 4.x to project

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>4.3.1.Final</version>
</dependency>

This is an implementation of JSR 303

2. Validation annotation

There is a few difference with the validation by using Spring's Validator Interface. We define the constraints in object such properties:

public class User {
    @NotEmpty(message="First Name is required")
    private String firstName;
    @NotEmpty
    private String lastName;    
    @CodeValidator
    private String code;    
    @NotEmpty
    private String password;    
    @NotEmpty
    private String repassword;

.... 

}

For more details about validation annotations, have a look at Hibernate Validator,

3. Support validation JSR 303

To support JSR 303 in Spring application we modify the *-servlet.xml to add

<mvc:annotation-driven/>

or

<bean id="validator"
          class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean"/>

A JSR-303 provider, such as Hibernate Validator, is expected to be present in the classpath and will be detected automatically. 

4. Controller

In controller, when you want to validate an object, you put the @Valid annotation in front of its place, the framework will detect and make validation for us.

@RequestMapping(value = "/modifyUser", method = RequestMethod.POST)
    public ModelAndView updateUser(@Valid @ModelAttribute("user") User user, BindingResult bindingResult) {
        if (bindingResult.hasErrors()) {
            // show errors
            return new ModelAndView("modifyUser", "user", user);
        } else {
            // success
            return new ModelAndView("viewUser", "user", user);
        }   
    }

5. Configure ResourceBundle

• Create new properties file in folder src/main/resources
• Create new bean instance in *-servlet.xml to load resource file

<bean id="messageSource"

    class="org.springframework.context.support.ResourceBundleMessageSource">

    <property name="basename" value="application" />

</bean>

Normally, the error message must follow [Constraint].[Bean name].[Property name]

For example, the application.properties contains:

NotEmpty.user.firstName = First Name is required

NotEmpty.user.lastName = Last Name is required

NotEmpty.user.password = Password is required

NotEmpty.user.repassword = Retype password is required

6. Prepare JSP page

Do not have anything new in JSR 303 for JSP, you do it as well as Spring's Validator Interface

<tr>
    <td><form:label path="firstName">First Name</form:label></td>
    <td>
        <form:input path="firstName" />
        <form:errors path="firstName" class="errors" />
    </td>
</tr>

References:

• http://static.springsource.org/spring/docs/3.1.x/spring-framework-reference/html/validation.html#validation-beanvalidation
• http://hibernate.org/subprojects/validator

Source code:

• For the demonstration, please download source code from HERE
• My repository on Github