How do I retrieve default validation messages from Hibernate Validator?

I’m trying to retrieve a default validation error-message using MessageSource. The code I’m working with uses reflection to retrieve the value of the message parameter. On a constraint that does not override the message parameter, I would like to retrieve the default error message. When I invoke the message method on the validation annotation, I get {org.hibernate.validator.constraints.NotBlank.message} (for example, for the @NotBlank annotation). I then tried to use MessageSource to get the error message like so:

String message = messageSource.getMessage(key, null, Locale.US);

I tried setting key to {org.hibernate.validator.constraints.NotBlank.message}, org.hibernate.validator.constraints.NotBlank.message (removed braces) and even org.hibernate.validator.constraints.NotBlank but I keep getting null. What am I doing wrong here?

UPDATE

A clarification. I am under the impression that Spring comes with a default message.properties file for its constraints. Am I correct in this assumption?

UPDATE

Changing the name of the question to better reflect what I was trying to do.

Answer

After running into a blog post from one of the Hibernate guys, and after digging around in the Hibernate Validator source, I think I’ve figured it out:

public String getMessage(final Locale locale, final String key) {
    PlatformResourceBundleLocator bundleLocator = new PlatformResourceBundleLocator("org.hibernate.validator.ValidationMessages");
    ResourceBundle resourceBundle = bundleLocator.getResourceBundle(locale);

    try {
       final String k = key.replace("{", "").replace("}", "");
       return resourceBundle.getString(k);
    }
    catch (MissingResourceException e) {
       return key;
    }
}

So first, you have to instantiate a PlatformResourceBundleLocator with the default validation messages. Then you retrieve a ResourceBundle from the locator and use that to get your message. I don’t believe this performs any interpolation though. For that you have to use an interpolator; the blog post I linked to above goes into more detail about that.

UPDATE

Another (easier) way is to update your applicationContext.xml and do this:

<bean id="resourceBundleSource" class="org.springframework.context.support.ResourceBundleMessageSource">
    <property name="basenames">
        <list>
            <value>org.hibernate.validator.ValidationMessages</value>
        </list>
    </property>
</bean>

Now your MessageSource is populated with the default messages and you can do messageSource.getMessage(). In fact, this is probably the best way.