injectionPoint.getBean() returns null if bean is an EJB bean in Java EE 7 (CDI 1.1)

问题

I want to get bean from producer method in order to read its properties. In some scenarios the bean is a EJB Singleton bean.

I've simplified my code to focus on the problem.

My simple qualifier:

@Qualifier
@Retention(RUNTIME)
@Target({TYPE, METHOD, FIELD, PARAMETER})
public @interface InjectMe {}

Simple producer:

@Dependent
public class SimpleProducer {

    @Produces
    @InjectMe
    public String getInjectMe(InjectionPoint ip) {
        // ip.getBean() returns null for some reason   
        return "ip=" + ip + ", bean=" + ip.getBean();
    }
}

EJB (Singleton):

@Singleton
@Startup
public class SimpleSingleton {

    @Inject
    @InjectMe
    private String injectMe;

    @PostConstruct
    public void init() {
        System.out.println(injectMe);
   }

}

Console output:

Info: ip=[BackedAnnotatedField] @Inject @InjectMe private com.test.ejb.SimpleSingleton.injectMe, bean=null

When I change Singleton bean to CDI bean everything works fine (ip.getBean() returns not null). It also worked in Java EE 6 even with Singleton bean but it does not in Java EE 7. I am using Glassfish 4 application server.

Is this behavior specified somewhere?

回答1:

Using

injectionPoint.getMember().getDeclaringClass()

works for me in WildFly 10.1.0 and I also quickly tested it in Payara Server 4.1.1.162 #badassfish (build 116). I also did a test on brand new Payara Server 4.1.1.164 #badassfish (build 28). However,I had to change the scope of the producer bean to @ApplicationScoped. Default scope did not work. In my case, it even makes sense :)

The

injectionPoint.getBean().getBeanClass()

method worked for me in the old Payara, but not in the new WildFly 10.1.0.Final and new Payara Server 4.1.1.164 #badassfish (build 28).

If you have a look at Payara, the current new version 164 contains Weld 2.4.0.Final and WildFly 10.1.0Final uses version 2.3.5.Final. In both versions, the classical code does not work !

The conclusion is, on older CDI implementations (Weld), it works. In some newer Weld (introduced in Payara 161), the behavior changed. I do not know if this is intentional or not.

However, the solution is to use

injectionPoint.getMember().getDeclaringClass()

and annotate the producer bean with

@javax.enterprise.context.ApplicationScoped

annotation.

来源：https://stackoverflow.com/questions/34643780/injectionpoint-getbean-returns-null-if-bean-is-an-ejb-bean-in-java-ee-7-cdi-1

标签

cdi

ejb-3.1

glassfish-4

java-ee-7