Good patterns for unit testing form beans that have annotation-based validation in Spring MVC

Question

When using annotation based validation for a form bean, what is the best practice for unit-testing those beans in order to ensure that correct validations annotations are sp

Answer 1

You can test it easily.

Let's say you are using Hibernate Validator. More or less, it should be something like this

    import javax.validation.ConstraintViolation;
    import junit.framework.Assert;
    import org.hibernate.validator.HibernateValidator;
    import org.junit.Before;
    import org.junit.Test;
    import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;

 private LocalValidatorFactoryBean localValidatorFactory;


@Before
public void setup() {
    localValidatorFactory = new LocalValidatorFactoryBean();
    localValidatorFactory.setProviderClass(HibernateValidator.class);
    localValidatorFactory.afterPropertiesSet();
}

  @Test
  public void testNullValidationError() {
        final MyForm myForm= new MyForm ();
        myForm.setName(null);
        Set> constraintViolations =      localValidatorFactory.validate(myForm);
        Assert.assertTrue("Your error message", constraintViolations.notNull == null);
    }