4 Replies Latest reply on Mar 12, 2002 10:34 AM by Chris Mactaggart

    Applet getting ClassCastException on lookup

    Christian Holliday Newbie

      I am trying to create a simple applet that receives topic messages. I get a ClassCastException on the lookup. I tried to use the example in the documentation but to no avail. I am using appletviewer. My code looks like this.

      Properties jndiProps = new Properties() ;
      jndiProps.setProperty("java.naming.factory.initial", "org.jnp.interfaces.NamingContextFactory" ) ;
      jndiProps.setProperty("java.naming.factory.url.pkgs", "org.jboss.naming:org.jnp.interfaces" ) ;

      Context context = new InitialContext(jndiProps);

      TopicConnectionFactory topicFactory =
      (TopicConnectionFactory)context.lookup("ConnectionFactory");


      The code dies on assigning the topicFactory to the lookup
      exception is:

      java.lang.ClassCastException: javax.naming.Reference

      Can anybody help.

      Thanx,
      Christian

        • 1. Re: Applet getting ClassCastException on lookup
          Christian Holliday Newbie

          Nevermind I got to work with Netscape browser.

          • 2. Re: Applet getting ClassCastException on lookup
            Chris Mactaggart Newbie

            I am having the same problem

            import java.applet.Applet;
            import java.awt.Graphics;

            import java.util.Hashtable;

            import javax.naming.Context;
            import javax.naming.InitialContext;
            import javax.naming.NamingException;

            import javax.jms.TopicConnectionFactory;
            import javax.jms.TopicConnection;
            import javax.jms.Session;
            import javax.jms.Topic;
            import javax.jms.TopicSubscriber;
            import javax.jms.TopicSession;
            import javax.jms.JMSException;
            import javax.jms.Message;
            import javax.jms.TextMessage;
            import javax.jms.MessageListener;


            public class LatencyApplet extends Applet
            {
            Graphics g = null;

            String error = "er ";

            public void init()
            {
            Hashtable props = new Hashtable();





            try
            {
            props.put(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
            props.put(Context.PROVIDER_URL, "localhost:1099");
            props.put("java.naming.rmi.security.manager", "yes");
            props.put(Context.URL_PKG_PREFIXES, "org.jboss.naming");


            Context context = new InitialContext(props);

            error += "created context\r\n";

            TopicConnectionFactory topicFactory = (TopicConnectionFactory)context.lookup("UILConnectionFactory");

            error += "created topic factory\15\12";

            TopicConnection topicConnection = topicFactory.createTopicConnection();

            error += "created topic connection\15\12";

            TopicSession topicSession = topicConnection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);



            Topic topic = (Topic)context.lookup("topic/heartbeat");



            TopicSubscriber topicSubscriber = topicSession.createSubscriber(topic);



            topicSubscriber.setMessageListener(new MsgListener());

            topicConnection.start();




            }
            catch(NamingException eNAM)
            {
            error += eNAM.getMessage();
            }

            catch(JMSException eJMS)
            {
            error += "JMS ERROR ";
            //error += eJMS.getLocalizedMessage();
            }

            }

            public void paint(Graphics g)
            {
            try
            {
            g.drawString(error, 100, 100);

            for(int i = 0; i < 100; i++)
            {
            g.drawString(String.valueOf(Latency.getLatency()), 25, 25);

            Thread.sleep(1000);
            }
            }
            catch(Exception e)
            {

            }
            }
            }




            Help

            • 3. Re: Applet getting ClassCastException on lookup
              Christian Holliday Newbie

              I am not sure what I had to do to get that working. My code now looks like this though.

              Properties jndiProps = new Properties() ;
              jndiProps.setProperty("java.naming.factory.initial", "org.jnp.interfaces.NamingContextFactory" ) ;
              jndiProps.setProperty("java.naming.factory.url.pkgs", "org.jboss.naming:org.jnp.interfaces" ) ;
              jndiProps.setProperty("java.naming.provider.url", "myhostname.mynetwork.com:1099" ) ;

              Context context = new InitialContext(jndiProps);

              TopicConnectionFactory topicFactory =
              (TopicConnectionFactory)context.lookup("RMIConnectionFactory");

              topicConnection = topicFactory.createTopicConnection();

              topicSession = topicConnection.createTopicSession(
              false, Session.AUTO_ACKNOWLEDGE);

              topic = (Topic)context.lookup("topic/application");

              topicSubscriber = topicSession.createSubscriber(topic);

              topicSubscriber.setMessageListener(msgListener);

              topicConnection.start();


              And I have a jndi.properties file in my applet directory that looks like this

              java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory
              java.naming.factory.url.pkgs=org.jnp.interfaces
              java.naming.provider.url=localhost

              You also have to make sure your applet includes the archive jar's in your html file.

              <APPLET CODE = "YourApplet.class" CODEBASE="/prdjar/" ARCHIVE = "./jbossmq-client.jar,
              ./jboss-client.jar, ./sl2.jar, ./jboss-j2ee.jar, ./jbosssx-client.jar, ./jnp-client.jar, ./jndi.jar,
              ./jaas.jar, ./log4j.jar" WIDTH = 800 HEIGHT = 400>


              Let me know if this helps

              Christian

              • 4. Re: Applet getting ClassCastException on lookup
                Chris Mactaggart Newbie

                I figured out my problem. I mistyped the file name of one of the .jar files that I needed in the applet tag in my html.