Web services and EJB3 @resource annotation

Question

This block of code works fine when NetworkViewBean is left as a @Stateless session bean.
Once I have JDeveloper 10.1.3 production expose it as a web service, I can no longer call the Entity Manager @Resource.
I always get a java.lang.NullPointerException returned.
Any ideas?? thanks for your help!
@WebService(name = "NetworkViewWS", serviceName = "NetworkViewWS")
public class NetworkViewBean {
@Resource
private EntityManager em;
public NetworkViewBean() { }
public String getDeviceVendorModel(String name) {
if (name == null || name.length()== 0) return "Null Input Parameter Specified";
NetDevice N= null;
try {
N= (NetDevice)em.createNamedQuery("findByDeviceName").setParameter(0, name).getSingleResult();
catch(Exception E) { E.printStackTrace();  return null; }
return "Vendor= "+ N.getVendor()+ ", Model= "+ N.getModelNumber();

Answer 1

Hi Joshua,
The problem is that you are using a regular Java web service and in 10.1.3.0.0 we do not have support for dependency injection in the container in the web container i.e. you cannot use annotations such as EJB, Resource in any classes in the web container.
You have two options:
1. Lookup an EJB from regular Java web service (JSR-181)
or
2. Make your Web service as a EJB 3.0 web service
Here what you can do to create an EJB 3.0 web service from JDev
1. Create an EJB 3.0 Session bean with remote interface
2. Change your remote interface to a web service end-point change @Remote to @WebService (import javax.jws.WebService)
3. You do not have to use @WebMethod, we automatically expose all methods in the end-point interface in the web service
4. You can inject EJB using @EJB
5. Create a deployment profile for the EJB-jar and deploy the ejb-jar and the EJB will be exposed as a web service. The context-uri for the web service will be /ejb-jarName
Hope this helps!
-Debu Panda
OC4J Product Management
blog: http://debupanda.com
-Debu