EJB warning: WELD-000411: ... Consider restricting events using @WithAnnotations or a generic type with bounds

Question

Here is the code to do some tasks before web application is launched (I'm using glassfish4):

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.ejb.Singleton;
import javax.ejb.Startup;
import javax.servlet.ServletContextEvent;
/**
 *
 * @author Ernestas Gruodis
 */
@Startup
@Singleton
public class ServerInit {
    /**
     * Do some code execution before web application starts up.
     */
    @PostConstruct
    public void init() {
        System.out.println("Initialising");
    }
    /**
     * Do some code execution on web application exit.
     * @param sce the servlet context event.
     */
    @PreDestroy
    public void destroy(ServletContextEvent sce) {

    }
}

But during startup I get these warnings:

WELD-000411: Observer method [BackedAnnotatedMethod] private org.glassfish.jersey.gf.cdi.internal.CdiComponentProvider.processAnnotatedType(@Observes ProcessAnnotatedType) receives events for all annotated types. Consider restricting events using @WithAnnotations or a generic type with bounds.

WELD-000411: Observer method [BackedAnnotatedMethod] org.glassfish.sse.impl.ServerSentEventCdiExtension.processAnnotatedType(@Observes ProcessAnnotatedType, BeanManager) receives events for all annotated types. Consider restricting events using @WithAnnotations or a generic type with bounds.

What is wrong here?

Answer 1

These warnings are caused by implicit CDI scanning in GlassFish. Resolve this by defining a beans.xml file, where you set the bean-discovery-modeto none. For example, in a Maven project place beans.xml under src/main/resources/META-INF/, where your beans.xml file might look like this:

<beans xmlns="http://xmlns.jcp.org/xml/ns/javaee"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee 
        http://xmlns.jcp.org/xml/ns/javaee/beans_1_1.xsd"
       bean-discovery-mode="none">
</beans>

This will turn off scanning for your entire application so make sure to annotate properly where needed. You may also change the global settings of GlassFish to disable scanning for all apps using the asadmin command:

asadmin set configs.config.server-config.cdi-service.enable-implicit-cdi=false

For more info on this I recommend reading Enable and disable implicit scanning per JAR in the glassfish issue queue in github.