servlets - How to inject dependencies into HttpSessionListener, using Spring?

Question

How to inject dependencies into HttpSessionListener, using Spring and without calls, like context.getBean("foo-bar") ?

Answer 1

Since the Servlet 3.0 ServletContext has an "addListener" method, instead of adding your listener in your web.xml file you could add through code like so:

@Component
public class MyHttpSessionListener implements javax.servlet.http.HttpSessionListener, ApplicationContextAware {

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        if (applicationContext instanceof WebApplicationContext) {
            ((WebApplicationContext) applicationContext).getServletContext().addListener(this);
        } else {
            //Either throw an exception or fail gracefully, up to you
            throw new RuntimeException("Must be inside a web application context");
        }
    }           
}

which means you can inject normally into the "MyHttpSessionListener" and with this, simply the presence of the bean in your application context will cause the listener to be registered with the container