java - How to use annotation validation in Spring with error message gotten from properties file?

Question

I'm a Spring newbie.

I set up validation in my domain class like this:

public class Worker {

    @NotNull(message="Name must be input")
    @Size(min=1,max=50, message="Name must not exceed 50 characters")
    private String name;
...

}

Here's the jsp file:

<form:input path="code" readonly="false" />
<font color="red"><form:errors path="code" />

And the controller code:

@RequestMapping(value="/test",method=RequestMethod.POST)
    public void form(@Valid Worker worker, BindingResult result) {

        if (result.hasErrors()) {
            return;
        }
...

It works, but how can I replace "Name must not exceed 50 characters" with some text (like worker.name.overflow) in my messageSource? May I need to add a messageResolver into BindingResult?

All the search result seems to say about writing a custom Validator class, but I want to use annotation for now. I'm pretty sure there's a way, because in this question someone has done that.

Answer 1

To tell Hibernate validator to do a lookup on a code, put the value of message in braces, e.g., @NotNull(message="{worker.name.NotNull}", then put the translation in ValidationMessages.properties in the root of your classpath (/WEB-INF/classes, resources folder in Maven, etc.).

The validator implementation looks those up independently on its own, and they go on the BindingResult already translated as the default message. Happens outside of the Spring messagesource. You could in theory override the LocalValidatorFactory bean to put the validator's message output onto the Errors object as the code and then leave the braces off in the annotation so that the Hibernate Validator passes it through. The source code that turns JSR-303 ConstraintViolations into Spring Errors is simple enough to read and extend. It just puts the name of the annotation on as code, the annotation properties as args, and then the validator's translation as the default message. You can read the implementation here.

You can add a javax.validation.MessageInterpolator to your javax.validation.Configuration to tell it to look for messages in other properties files. If you're using the Spring LocalValidatorFactory bean, it has a setMessageInterpolator() on it that you can use to inject one. Check this source for the Hiberate provider implementation.