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?