1 Reply Latest reply on Sep 5, 2007 6:55 AM by jaikiran pai

    javax.naming.NamingException : could not dereference object[

    ashwin dhiware Newbie

      HI Someone please help me i am new to entity beans. I deployed my application successfully to jboss-4.0.4.GA server (default) i don't have ejb3 support. In my application i want to display the records of Book table (Library database)from mysql. So i created 1st entity bean first & then i developed servlet & run xdoclet after creating interfaces i make all possible changes & lastly managed to deployed the application
      Now my problem is that when i request the servlet "ReadData" through browser then Exception is arises.

      i am using
      JBoss IDE1.6
      JBoss 4.0.4.GA server
      mysql 5 with mysql connector
      Debian Etch

      my deployment descriptors are:

      ejb-jar.xml is


      <ejb-jar >
      <![CDATA[No Description.]]>
      <display-name>exampleBMPJAR</display-name>
      <enterprise-beans>

      <![CDATA[Description for exampleBMP]]>
      <display-name>Name for exampleBMP</display-name>
      <ejb-name>exampleBMP</ejb-name>
      example.BMP.interfaces.exampleBMPHome
      example.BMP.interfaces.exampleBMP

      <local-home>example.BMP.interfaces.exampleBMPLocalHome</local-home>

      example.BMP.interfaces.exampleBMPLocal

      <ejb-class>example.BMP.ejb.exampleBMPBean</ejb-class>
      <persistence-type>Bean</persistence-type>
      <prim-key-class>example.BMP.interfaces.exampleBMPPK</prim-key-class>
      False
      <resource-ref>
      <res-ref-name>jdbc/bmp-exBMP</res-ref-name>
      <res-type>javax.sql.DataSource</res-type>
      <res-auth>Container</res-auth>
      <res-sharing-scope>Shareable</res-sharing-scope>
      </resource-ref>

      </ejb-jar>

      jboss.xml is

      <enterprise-beans>

      <ejb-name>exampleBMP</ejb-name>
      <jndi-name>exampleBMPBean</jndi-name>

      </enterprise-beans>

      jboss-web.xml is

      <jboss-web>
      <ejb-ref>
      <ejb-ref-name>ejb/exampleBMP</ejb-ref-name>
      <jndi-name>ejb/exampleBMPBean</jndi-name>
      </ejb-ref>
      </jboss-web>

      web.xml is

      <servlet-name>ReadData</servlet-name>
      <display-name>Name for ReadData</display-name>
      <![CDATA[Description for ReadData]]>
      <servlet-class>example.BMP.Web.ReadData</servlet-class>

      <servlet-mapping>
      <servlet-name>ReadData</servlet-name>
      <url-pattern>/ReadData</url-pattern>
      </servlet-mapping>
      <ejb-ref >
      <![CDATA[Reference to the exampleBMP EJB]]>
      <ejb-ref-name>ejb/exampleBMP</ejb-ref-name>
      <ejb-ref-type>BMP</ejb-ref-type>
      example.BMP.interfaces.exampleBMPHome
      example.BMP.interfaces.exampleBMP
      <local-home>example.BMP.interfaces.exampleBMPLocalHome</local-home>
      example.BMP.interfaces.exampleBMPLocal
      </ejb-ref>
      </web-app>

      My "ReadData" Servlet is
      public class ReadData extends HttpServlet {
      exampleBMPHome home;
      protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException,IOException
      { resp.setContentType("text/html");
      PrintWriter out = resp.getWriter();
      try{
      Context ctx =new InitialContext();
      Object obj =ctx.lookup("java:/comp/env/ejb/exampleBMP");
      exampleBMPHome home =(exampleBMPHome)PortableRemoteObject.narrow(obj,exampleBMPHome.class);
      ResultSet rs=home.DisplayData();String s1 = rs.getString("BName");
      String s2 = rs.getString("BAuthor");
      int s3 = rs.getInt("BPrice");
      int s4 = rs.getInt("LCno");
      while(rs.next())
      {
      out.print("");
      out.print("============================================");
      out.println("<h3><FONT COLOR=RED> The Book Name is =</h3><h2>"+s1);
      out.print("</h2>");
      out.println("<h3><FONT COLOR=RED> The Author Name is =</h3><h2>"+s2);
      out.print("</h2>");
      out.println("<h3><FONT COLOR=RED> The Price of Book is =</h3><h2>"+s3);
      out.print("</h2>");
      out.println("<h3><FONT COLOR=RED> The Library card No. is=</h3><h2>"+s4);
      out.print("</h2>");
      out.println("==============================================");
      out.print("");
      out.print("");
      }
      }
      catch(Exception e){
      System.out.println("The Exception arises is ="+e);
      }
      finally {
      out.println("");
      out.close();
      }
      }
      }

      my interfaces r
      exampleBMP is

      public interface exampleBMP extends javax.ejb.EJBObject
      {
      }
      & same exampleBMPLocal interface

      exampleBMPHome is
      public interface exampleBMPHome extends javax.ejb.EJBHome
      {
      public static final String COMP_NAME="java:comp/env/ejb/exampleBMP";
      public static final String JNDI_NAME="exampleBMP";
      public example.BMP.interfaces.exampleBMP create()throws javax.ejb.CreateException,java.rmi.RemoteException; public example.BMP.interfaces.exampleBMP findByPrimaryKey(exampleBMPPK key) throws javax.ejb.FinderException, java.rmi.RemoteException;
      public ResultSet DisplayData() throws java.rmi.RemoteException;
      }

      and same exampleBMPLocalHome interface

      Nw what is the exact problem in servlet coding where i put
      Object obj =ctx.lookup("java:/comp/env/ejb/exampleBMP");
      whether this is creating problem me as::
      javax.naming.NamingException : could not dereference object[Root cause is javax.naming.NameNotFoundException:ejb not bound]
      Please Help me.....Ashwin Dhiware BE(Computers)