I'm working on rest service and learning EJB at the same time. I just run my application with simple chain controller -> service -> DAO and my EJB hotelService is not injected -- it is null.
@Path("/hotels")
public class HotelsController {
@EJB
private HotelService hotelService;
@GET
@Produces(MediaType.APPLICATION_JSON)
public Response getHotelsList(@QueryParam("startDate") String startDate,
@QueryParam("endDate") String endDate) {
List<HotelsEntity> list = hotelService.getAll();
return ResponseFactory.response(Response.Status.OK, list);
}
}
Service
@Stateless
@EJB(beanInterface = HotelService.class, name = "HotelService")
public class HotelService {
@EJB
private HotelDAO hotelDAO;
public List<HotelsEntity> getAll() {
return hotelDAO.getAll();
}
public Hotel getHotelById(final String id) {
return hotelDAO.getHotelById(id);
}
}
DAO
@Stateless
public class HotelDAO {
@PersistenceContext(unitName = Constants.PERSISTENCE_UNIT)
private EntityManager em;
public List<HotelsEntity> getAll() {
// TODO complete me
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<HotelsEntity> criteria = builder.createQuery(HotelsEntity.class);
Root<HotelsEntity> root = criteria.from(HotelsEntity.class);
criteria.select(root);
TypedQuery<HotelsEntity> resultQuery = em.createQuery(criteria);
return resultQuery.getResultList();
}
I thought that issue may be in some eror during instatiation of HotelDAO but even without it mt HotelService is null.
Do you a have any opinion where is an issue can be?
StandardWrapperValve[javax.ws.rs.core.Application]: Servlet.service() for servlet javax.ws.rs.core.Application threw exception
java.lang.NullPointerException
at com.example.controller.HotelsController.getHotelsList(HotelsController.java:29)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:125)
at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:152)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:91)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:346)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:341)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:101)
at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:224)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
at org.glassfish.jersey.internal.Errors.process(Errors.java:267)
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317)
at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:198)
at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:946)
at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:323)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:372)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:335)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:218)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:357)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
at java.lang.Thread.run(Thread.java:745)
]]
المحلول
You need to either implement a @Local annotated interface that expresses the local view of that EJB bean, or you need to add the @LocalBean annotation to the HotelService class itself to explicitly state that it is a local no-interface view of that EJB.
@Stateless
@EJB(beanInterface = HotelService.class, name = "HotelService")
@LocalBean
public class HotelService {
// ...
}
If you want the service to be available outside of the container for RMI or EJB client execution, you'll need to create a @Local and @Remote view of that service and implement both.