CDI Inject into Abstract Class

Question

I have a set of code that will deploy and execute just fine in JDK 1.6 on Glassfish 3.1.2. However, if we update to Glassfish 4 and JDK 1.7 we get the following error trying to deploy the application:

org.jboss.weld.exceptions.IllegalArgumentException: WELD-001407 Cannot declare an injection point with a type variable: [BackedAnnotatedField] @Inject protected com.co.ejb.web.AjaxGridServlet.sourceInstance 
at org.jboss.weld.manager.InjectionTargetFactoryImpl.createInjectionTarget(InjectionTargetFactoryImpl.java:82)
at org.jboss.weld.manager.InjectionTargetFactoryImpl.createInjectionTarget(InjectionTargetFactoryImpl.java:68)
at org.jboss.weld.manager.BeanManagerImpl.createInjectionTarget(BeanManagerImpl.java:1039)
at org.jboss.weld.manager.BeanManagerImpl.fireProcessInjectionTarget(BeanManagerImpl.java:1197)
at org.glassfish.weld.WeldDeployer.firePITEvent(WeldDeployer.java:390)
at org.glassfish.weld.WeldDeployer.fireProcessInjectionTargetEvents(WeldDeployer.java:360)
at org.glassfish.weld.WeldDeployer.event(WeldDeployer.java:212)
at org.glassfish.kernel.event.EventsImpl.send(EventsImpl.java:131)
at org.glassfish.internal.data.ApplicationInfo.load(ApplicationInfo.java:328)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:493)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:219)
at org.glassfish.deployment.admin.DeployCommand.execute(DeployCommand.java:491)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2.execute(CommandRunnerImpl.java:537)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:546)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:1423)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.access$1500(CommandRunnerImpl.java:108)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1762)
at org.glassfish.deployment.autodeploy.AutoOperation.run(AutoOperation.java:164)
at org.glassfish.deployment.autodeploy.AutoDeployer.deploy(AutoDeployer.java:595)
at org.glassfish.deployment.autodeploy.AutoDeployer.deployAll(AutoDeployer.java:482)
at org.glassfish.deployment.autodeploy.AutoDeployer.run(AutoDeployer.java:410)
at org.glassfish.deployment.autodeploy.AutoDeployer.run(AutoDeployer.java:401)
at org.glassfish.deployment.autodeploy.AutoDeployService$1.run(AutoDeployService.java:233)
at java.util.TimerThread.mainLoop(Timer.java:555)
at java.util.TimerThread.run(Timer.java:505)
Caused by: org.jboss.weld.exceptions.DefinitionException: WELD-001407 Cannot declare an injection point with a type variable: [BackedAnnotatedField] @Inject protected com.co.ejb.web.AjaxGridServlet.sourceInstance
at org.jboss.weld.bootstrap.Validator.checkFacadeInjectionPoint(Validator.java:765)
at org.jboss.weld.bootstrap.Validator.validateInjectionPointForDefinitionErrors(Validator.java:352)
at org.jboss.weld.injection.producer.InjectionTargetService.validateProducer(InjectionTargetService.java:39)
at org.jboss.weld.manager.InjectionTargetFactoryImpl.createInjectionTarget(InjectionTargetFactoryImpl.java:79)
... 24 more

The file in question are:

BaseJasonServlet

public abstract class BaseJsonServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doProcess(request, response);
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doProcess(request, response);
    }

    protected void doProcess(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");
        this.process(request, response);
    }

    protected abstract void process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException;
}

AjaxGridServlet which extends BaseJsonServlet. The issue is in this file where we inject an instance of TSource.

public abstract class AjaxGridServlet<TSource extends AjaxGridSource<?,?>> extends BaseJsonServlet {
    private static final long serialVersionUID = 1L;

    @Inject
    protected Instance<TSource> sourceInstance;

    @Override
    protected void process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        TSource source= sourceInstance.get();
        source.process(request, response);
        response.getWriter().write(source.toJsonString());
        }
}

AjaxGridServlet is then extended by a webservlet

@WebServlet("/api/admin-dashboard")
public class AdminDashboard extends AjaxGridServlet<AdminDashboardSource> {
    private static final long serialVersionUID = 1L;
}

Any help would be greatly appreciated. Thanks.

Answer 1

What the message tells you, is that you can't have an Instance with a type variable. That is, you can't use TSource there.

You should use Instance<AjaxGridSource> instead.