Spring MVC + Hibernate Validator + Velocity

Question

I can't seem to get basic validation working with Spring MVC.

I have the following POJO:

public class Example {

    @NotNull(message="You must enter a value")
    @Size(min=2, max="2", message="You must enter 2 characters")
    private String value;

    public String getValue() { return value; }
    public void setValue(String value) { this.value = value; }

}

My very basic controller looks like this:

@Controller
@RequestMapping("/value.vm")
public class ValueController {

    @Autowired
    private Validator validator;

    @RequestMapping()
    public ModelAndView display(@Valid @ModelAttribute("example") Example e, BindingResult result) {
        //Details omitted
    }

My velocity template is equally as simple:

<form target="_self" enctype="application/x-www-form-urlencoded" action="/value.vm" method="post">
    #springBind("example")
    #springFormInput("example.value", "")
    #springShowErrors("<br />", "")
</form>

My servlet.xml file includes:

<mvc:annotation-driven />

If I manually validate a blank form submission (ie validator.validate(e)), I see that my error messages are being generated, however they never exist on my BindingResult.

Any ideas why my binding result is not getting these errors?

Answer 1

I was mistakenly using:

javax.validation.Validator 

When I needed to be using

org.springframework.validation.Validator

Changing to this version, and modifying the validation code to:

validator.validate(e, result);

solved my problem.

Answer 2

You can still use JSR 303 @Valid annotation to automatically invoke validation using javax.validation.Validator without invoking it manually.

This is enabled by default by spring if you include <mvc:annotation-driven/> element to your application context or @EnableWebMvc when you are using Java config

For this to work you need to have an implementation for Bean Validation API eg Hibernate Validator