0 Replies Latest reply on Jul 26, 2005 12:50 PM by Randy Wilkinson

    Generic interceptor with dependancy injection

    Randy Wilkinson Newbie

      I am trying to create an interceptor class that uses a @EJB tag to inject a site specific implementation of an interface. This is a common use case for our product where each site has specific code that is executed based on a trigger (method invocation). I am simply modifing the EJBTrail example trying to make this work. The following code compiles cleanly, deploys cleanly, yet throw an execption on execution.

      /*** Interceptor base class *****/
      package trail.interceptor;
      
      import javax.annotation.EJB;
      import javax.ejb.AroundInvoke;
      import javax.ejb.InvocationContext;
      
      
      public class BasicIntercept {
      
       // Inject EJB
       @EJB
       CalcTwoNumbers calc2;
      
       @AroundInvoke
       public Object trigger (InvocationContext ctx)
       throws Exception {
       return(calc2.doIt(ctx));
       }
      
      }
      
      /**** implementation interface ********/
      package trail.interceptor;
      
      import javax.ejb.InvocationContext;
      
      
      public interface CalcTwoNumbers {
      
       public Object doIt (InvocationContext ctx)
       throws Exception;
      
      }
      
      /***** simple example implementation ****/
      package trail.interceptor;
      
      import javax.annotation.EJB;
      import javax.ejb.*;
      
      
      
      @Stateless
      public class CalcTwoNumbersMulti implements CalcTwoNumbers {
      
      
       public Object doIt (InvocationContext ctx)
       throws Exception {
       int x = 3;
       int y = 2;
       CalculatorBean cal = (CalculatorBean) ctx.getBean();
       String className = ctx.getBean().getClass().getName();
       String methodName = ctx.getMethod().getName();
      
      
       cal.setTrace("Intercepted call to "+ className + "." + methodName +
       "!\nCalcTwoNumber x=" + x + " y=" + y +
       " result = " + (x * y) );
       try {
       return ctx.proceed();
       } catch(Exception e) {
       throw e;
       } finally {
       System.out.println("CalcTwoNumber x=" + x + " y=" + y +
       " result = " + (x * y) );
      
       }
      
       }
      
      }
      
      /*** setup interceptor ***/
      package trail.interceptor;
      
      import javax.ejb.*;
      import java.util.*;
      import java.io.Serializable;
      
      //TODO: Fix the client
      @Stateful
      @Interceptor(BasicIntercept.class)
      public class CalculatorBean implements Calculator, Serializable {
      ......
      


      According to the examples this should work and I cannot find anything in the EJB3.0 spec that forbids this type of design. But here is the exception:
      javax.ejb.EJBException: null; CausedByException is:
       null
       org.jboss.ejb3.tx.Ejb3TxPolicy.handleExceptionInOurTx(Ejb3TxPolicy.java:46)
       org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:70)
       org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:134)
       org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:88)
       org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:72)
       org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:88)
       org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:63)
       org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:88)
       org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:93)
       org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:88)
       org.jboss.ejb3.stateful.StatefulContainer.localInvoke(StatefulContainer.java:122)
       org.jboss.ejb3.stateful.StatefulLocalProxy.invoke(StatefulLocalProxy.java:86)
       $Proxy87.setTrace(Unknown Source)
       org.apache.jsp.services.interceptor.calculator_jsp._jspService(org.apache.jsp.services.interceptor.calculator_jsp:80)
       org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
       javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
       org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)
       org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
       org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
       javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
       org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:81)
      


      Any help would be appreciated.

      Randy