Servlet Event to CDI event bus PE

[nickarls]

Here is a trivial class that pushes the Servlet Listener events to the CDI event bus so that you can do a

     public void here(@Observes @Created HttpSessionEvent e) {
          // session created, do work
     }

@WebListener
public class ServletListener implements ServletContextListener,
          ServletContextAttributeListener, HttpSessionListener,
          HttpSessionAttributeListener, HttpSessionActivationListener,
          HttpSessionBindingListener, ServletRequestAttributeListener {

     private BeanManager beanManager;
     
     public ServletListener() {
          try {
               beanManager = (BeanManager) new InitialContext().lookup("java:app/BeanManager");
          } catch (NamingException e) {
               e.printStackTrace();
          }
     }
     
     private void fireEvent(Object payload, Annotation... qualifiers) {
          beanManager.fireEvent(payload, qualifiers);
     }
     
     public void contextDestroyed(ServletContextEvent e) {
          fireEvent(e, new AnnotationLiteral<Destroyed>() {});
     }

     public void contextInitialized(ServletContextEvent e) {
          fireEvent(e, new AnnotationLiteral<Initialized>() {});
     }

     public void attributeAdded(ServletContextAttributeEvent e) {
          fireEvent(e, new AnnotationLiteral<AttributeAdded>() {});
     }

     public void attributeRemoved(ServletContextAttributeEvent e) {
          fireEvent(e, new AnnotationLiteral<AttributeRemoved>() {});
     }

     public void attributeReplaced(ServletContextAttributeEvent e) {
          fireEvent(e, new AnnotationLiteral<AttributeReplaced>() {});
     }

     public void sessionCreated(HttpSessionEvent e) {
          fireEvent(e, new AnnotationLiteral<Created>() {});
     }

     public void sessionDestroyed(HttpSessionEvent e) {
          fireEvent(e, new AnnotationLiteral<Destroyed>() {});
     }

     public void attributeAdded(HttpSessionBindingEvent e) {
          fireEvent(e, new AnnotationLiteral<AttributeAdded>() {});
     }

     public void attributeRemoved(HttpSessionBindingEvent e) {
          fireEvent(e, new AnnotationLiteral<AttributeRemoved>() {});
     }

     public void attributeReplaced(HttpSessionBindingEvent e) {
          fireEvent(e, new AnnotationLiteral<AttributeReplaced>() {});
     }

     public void sessionDidActivate(HttpSessionEvent e) {
          fireEvent(e, new AnnotationLiteral<DidActivate>() {});
     }

     public void sessionWillPassivate(HttpSessionEvent e) {
          fireEvent(e, new AnnotationLiteral<WillPassivate>() {});
     }

     public void valueBound(HttpSessionBindingEvent e) {
          fireEvent(e, new AnnotationLiteral<ValueBound>() {});
     }

     public void valueUnbound(HttpSessionBindingEvent e) {
          fireEvent(e, new AnnotationLiteral<ValueUnbound>() {});
     }

     public void attributeAdded(ServletRequestAttributeEvent e) {
          fireEvent(e, new AnnotationLiteral<AttributeAdded>() {});
     }

     public void attributeRemoved(ServletRequestAttributeEvent e) {
          fireEvent(e, new AnnotationLiteral<AttributeRemoved>() {});
     }

     public void attributeReplaced(ServletRequestAttributeEvent e) {
          fireEvent(e, new AnnotationLiteral<AttributeReplaced>() {});
     }

}

and the qualifiers

@Qualifier
@Target({FIELD, PARAMETER})
@Retention(RUNTIME)
public @interface AttributeAdded {}

@Qualifier
@Target({FIELD, PARAMETER})
@Retention(RUNTIME)
public @interface AttributeRemoved {}

@Qualifier
@Target({FIELD, PARAMETER})
@Retention(RUNTIME)
public @interface AttributeReplaced {}

@Qualifier
@Target({FIELD, PARAMETER})
@Retention(RUNTIME)
public @interface Created {}

@Qualifier
@Target({FIELD, PARAMETER})
@Retention(RUNTIME)
public @interface Destroyed {}

@Qualifier
@Target({FIELD, PARAMETER})
@Retention(RUNTIME)
public @interface DidActivate {}

@Qualifier
@Target({FIELD, PARAMETER})
@Retention(RUNTIME)
public @interface Initialized {}

@Qualifier
@Target({FIELD, PARAMETER})
@Retention(RUNTIME)
public @interface ValueBound {}

@Qualifier
@Target({FIELD, PARAMETER})
@Retention(RUNTIME)
public @interface ValueUnbound {}

@Qualifier
@Target({FIELD, PARAMETER})
@Retention(RUNTIME)
public @interface WillPassivate {}

Notes:

1. For a pre-Servlet-3 appserver, register the listener yourself


2. For a spec-compliant server, use the correct JNDI URL for beanmanager ;-)


3. Servlet 3 asynch listeners not yet included, didn't find any JBoss branch where they would be present

This is just a proof-of-concept, I'll package it better and put it on in.relation.to. Perhaps a JSF-CDI event bridge, too(?)

Hopefully in Java EE 7, the servlet spec would just state what CDI-events it would broadcast and there would be no listeners ;-)