2 Replies Latest reply: Jun 15, 2012 4:40 AM by Riccardo Pasquini RSS

    java.lang.NullPointerException in EJB3 from JSP page

    Moazzam Munir Newbie

      I am developing my first EJB 3 application using JBOSS 7 as application server in Eclipse. The session bean is deployed successfully on the server but when i try to access it from the JSP page, then i get the java.lang.NullPointerException exception.

      Following is my code:

      Local Interface:

      package my.first;

      import javax.ejb.Local;

      @Local
      public interface CalculatorRemote {

           public float add(float x, float y);

           public float subtract(float x, float y);

           public float multiply(float x, float y);

           public float division(float x, float y);
      }

      Session bean:

       

      package my.first;

          import javax.ejb.LocalBean;
          import javax.ejb.Stateless;

          @Stateless(name = "CalculatorRemote")
          public class CalculatorBean implements CalculatorRemote {
              public float add(float x, float y) {
                  return x + y;
              }

              public float subtract(float x, float y) {
                  return x - y;
              }

              public float multiply(float x, float y) {
                  return x * y;
              }

              public float division(float x, float y) {
                  return x / y;
              }
          }

      JSP Page:

           <%!
            private CalculatorRemote calculator = null;
            float result=0;

            public void jspInit() {
            try {

            InitialContext ic = new InitialContext();

            calculator = (CalculatorRemote) ic
            .lookup("CalculatorRemote/Local");


            System.out.println("Loaded Calculator Bean");
          //CalculatorBean

            } catch (Exception ex) {
            System.out.println("Error:"+
            ex.getMessage());
            }
            }
            public void jspDestroy() {
            calculator = null;
            }
          %>

      Server Log File:

      17:17:20,552 INFO  [org.jboss.as.ejb3.deployment.processors.EjbJndiBindingsDeploymentUnitProcessor] (MSC service thread 1-4) JNDI bindings for session bean named CalculatorRemote in deployment unit deployment "EJBsession.jar" are as follows:

              java:global/EJBsession/CalculatorRemote!my.first.CalculatorBean
              java:app/EJBsession/CalculatorRemote!my.first.CalculatorBean
              java:module/CalculatorRemote!my.first.CalculatorBean
              java:global/EJBsession/CalculatorRemote!my.first.CalculatorRemote
              java:app/EJBsession/CalculatorRemote!my.first.CalculatorRemote
              java:module/CalculatorRemote!my.first.CalculatorRemote
              ......
              ......
              ......

              17:23:44,105 ERROR [stderr] (http--127.0.0.1-8080-1) java.lang.NullPointerException

              17:23:44,105 ERROR [stderr] (http--127.0.0.1-8080-1)    at org.apache.jsp.test_jsp._jspService(test_jsp.java:102)

              17:23:44,105 ERROR [stderr] (http--127.0.0.1-8080-1)    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)

              17:23:44,105 ERROR [stderr] (http--127.0.0.1-8080-1)    at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)

              ......
              ......
              ......

       

      Please help?