CDI doesn't work in a simple adapter

Question

I've added the CDI feature to the server.xml file<feature>cdi-1.2</feature>.

My maven module contains the beans.xml inside the <module_name>/src/main/resources/META-INF folder.

This is the beans.xml content:

<?xml version="1.0" encoding="UTF-8"?>
<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"
       version="1.1" bean-discovery-mode="all">
</beans>

But when I use the @Inject annotation it doesn't work, my bean is always null.

Code:

package ch.webapp.presentation;

...

@Path("/test/")
public class MyController {
    @Inject
    private MyService myService;

    @GET
    @Path("/foo/{count}")
    @OAuthSecurity(scope = "login")
    @Produces("application/json")
    public Response news(@PathParam("count") int count) {
        return Response
                .ok(myService.getBar(count))
                .build();
    }
}

EDIT:

That's my bean

package ch.webapp.service;

...

@RequestScoped
public class MyService {
    public String getBar(int count) {
        return "foo";
    }
}

I initialize jax-rs by extended the MFPJAXRSApplication class

package ch.webapp;

...

public class AccountApplication extends MFPJAXRSApplication {
    @Override
    protected void init() throws Exception {
    }

    @Override
    protected void destroy() throws Exception {
    }

    @Override
    protected String getPackageToScan() {
        return getClass().getPackage().getName();
    }
}

Environment details:

Launching mfp (WebSphere Application Server 8.5.5.8/wlp-1.0.11.cl50820151201-1942) on Java HotSpot(TM) 64-Bit Server VM, version 1.8.0_172-b11 (en_CH)

Console Product version: 8.0.0.00-20180717-175523

What's wrong?

Answer 1

First it seems that websphere jax-rs implementation does not integrate jax-rs resources automatically unless you annotate them appropriately.

Put the jax-rs in a CDI managed context by annotating it appropriately

@Path("/test/")
@javax.enterprise.context.RequestScoped
public class MyController {

    @Inject
    private MyService myService;

    @GET
    @Path("/foo/{count}")
    @OAuthSecurity(scope = "login")
    @Produces("application/json")
    public Response news(@PathParam("count") int count) {
        return Response
                .ok(myService.getBar(count))
                .build();
    }

}

Also be sure that the annotation used for your service is @javax.enterprise.context.RequestScoped

Answer 2

Based on the inputs provided by you please go through the below checklist.

1. Your services and controllers are in the same module and its packaging type is war, So you must place your beans.xml in this path src/main/resources/WEB-INF/beans.xml. (If this is Java EE 7 application then beans.xml is optional.

2. In your AccountApplication class try hardcoding the package name to ch.webapp.presentation

   @Override protected String getPackageToScan() { return "ch.webapp.presentation"; }

This is just to check Behaviour of MFPJAXRSApplication.getPackageToScan() method whether it is scanning the specified package only or its child packages too.

3. Except these, everything seems fine to me. If this still doesn't work add complete application startup logs so that community can find the root cause of it.

Answer 3

This is classical mistake. CDI works for managed beans (for instance EJB's and servlets). If you want to enable it on your JAXRS bean, you have to make it "managed", that is annotate MyController as (for instance) javax.annotation.ManagedBean or as a javax.ejb.Stateless.

Also beware that in case of webapp (.war), the beans.xml file has to be located in the WEB-INF folder !