Grails: Accessing spring beans in the destory closure of Bootstrap code?

Question

Hello,

I'm looking to access a bean in my destroy closure in the Bootstrap.groovy of my grails project. Any ideas on how to achieve this?

I seem to have no access to servletContext...?

Answer 1

Hmm, I can't find any examples of anyone even using the destroy block closure in Bootstrap. From the docs:

    It is not guaranteed that {{destroy}} will be called unless the 
application exits gracefully (for example by using the application 
server's shutdown command) so don't rely on it too much 

As a guess, I'd have to say that the servletContext has already been destroyed before the {{destroy}} closure of Bootstrap is executed, so that bean you're trying to access is gone already. Can anyone confirm?

Answer 2

Hey Willi ;)

You can obtain a a reference to the applicationContext from everywhere (including the destroy closure of BootStrap) using that chunk of code:

def ctx = org.codehaus.groovy.grails.web.context.ServletContextHolder.servletContext.getAttribute(org.codehaus.groovy.grails.web.servlet.GrailsApplicationAttributes.APPLICATION_CONTEXT);

or

def ctx = org.codehaus.groovy.grails.commons.ApplicationHolder.application.parentContext

Getting a reference to a bean is as easy as ctx.beanName.

Here is a small util class (written in Java) that can simplify this task:

import org.springframework.context.ApplicationContext;
import org.codehaus.groovy.grails.web.context.ServletContextHolder;
import org.codehaus.groovy.grails.web.servlet.GrailsApplicationAttributes;

public class SpringUtil {

    public static ApplicationContext getCtx() {
        return getApplicationContext();
    }

    public static ApplicationContext getApplicationContext() {
        return (ApplicationContext) ServletContextHolder.getServletContext().getAttribute(GrailsApplicationAttributes.APPLICATION_CONTEXT);
    }

    @SuppressWarnings("unchecked")
    public static <T> T getBean(String beanName) {
        return (T) getApplicationContext().getBean(beanName);
    }

}

and an example:

def bean = SpringUtil.getBean("beanName")

Cheers, Sigi

Answer 3

I know I'm all late here and all but since I found this via Google...

Your BootStrap class gets injected with Spring beans by name, just like all the services and controllers and stuff. If you want a bean, just def it by name and it'll show up. Otherwise, just def grailsApplication and go to grailsApplication.mainContext.getBean etc.