package examples.jms.messageformat;

import java.io.IOException;
import java.io.StringReader;
import java.util.Hashtable;
import javax.jms.*;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import weblogic.jms.extensions.WLQueueSession;
import weblogic.jms.extensions.XMLMessage;

/**
 * This class shows how to establish a connection to and receive messages from
 * a JMS queue.
 * <p>Run this class after you have run the ClientSend class to send XML
 * data to a JMS queue.  After ClientSend has sent its message, the Message-
 * driven EJB <code>MessageTraderBean</code> retrieves the XML data from the
 * queue, parses it, then sends the output to another JMS queue.  This class,
 * ClientReceive, gets the final message from this JMS queue.
 *
 * @author Copyright (c) 2005 by BEA Systems, Inc. All Rights Reserved.
 */

public class ClientReceive {

  public final static String JNDI_FACTORY="weblogic.jndi.WLInitialContextFactory";
  public final static String JMS_FACTORY="weblogic.examples.jms.messageformat.QueueConnectionFactory";
  public final static String QUEUE="weblogic.examples.jms.messageformat.exampleQueueReceive";
  private static String xmlMessage = null;

  public String getXmlMessage() { return xmlMessage; }

  /**
   * Establishes a connection to the JMS queue and receives the
   * trade result in the form of XML data.
   *
   * @exception NamingException if a JNDI naming exception occurred
   * @exception JMSException if a JMS exception occurred
   * @exception IOException if an IO naming exception occurred
   * @exception ParserConfigurationException if a parser configuration exception occurred
   * @exception SAXException if a SAX exception occurred
   */
  public void receive(String url)
    throws NamingException, JMSException, IOException,
      ParserConfigurationException, SAXException, Exception
  {
    // Look up the Queue and the QueueConnection Factory
    // in a JNDI naming and directory service, or create
    // them directly.

    Hashtable<String,String> env = new Hashtable<String,String>();
    env.put(Context.INITIAL_CONTEXT_FACTORY, JNDI_FACTORY);
    env.put(Context.PROVIDER_URL, url);
    Context context = new InitialContext(env);

    Queue queue = null;
    queue = (Queue)context.lookup(QUEUE);

    QueueConnectionFactory queueconnectionfactory = null;
    queueconnectionfactory = (QueueConnectionFactory)context.lookup(JMS_FACTORY);

    QueueConnection queueconnection = null;
    queueconnection = queueconnectionfactory.createQueueConnection();
    queueconnection.start();

    QueueSession queuesession = null;
    queuesession = (WLQueueSession)queueconnection.createQueueSession(false,
      Session.AUTO_ACKNOWLEDGE);

    // Create the QueueReceiver.
    QueueReceiver queuereceiver = null;
    queuereceiver = queuesession.createReceiver(queue);

    // Retrieve a XML message.  Validate
    // the XML before returning it.
    XMLMessage xmlmessage;

    while(true) {
       try {
         xmlmessage = (XMLMessage)queuereceiver.receive(1000);
       } catch(Exception e) {
         System.out.println("Failed to receive XML message: " + e.getMessage());
         throw e;
     }

     if(xmlmessage != null) {
       try {
         xmlMessage = xmlmessage.getText();

        // NOTE: This example demonstrates how to use JAXP
        // to obtain a parser in a CLIENT without explicitly referring
        // a particular parser implementation. Server-side objects
        // should use WebLogic's XML registry to specify and
        // obtain a parser. The following code sets the java system property used by
        // JAXP to determine which parser factory to return.

         System.setProperty("javax.xml.parsers.SAXParserFactory",
                            "weblogic.apache.xerces.jaxp.SAXParserFactoryImpl");

         SAXParserFactory fact = SAXParserFactory.newInstance();
         SAXParser sp = fact.newSAXParser();

         RequestHandler rh = new RequestHandler();
         InputSource inSource = new InputSource();

         inSource.setCharacterStream(new StringReader(xmlMessage));
         sp.parse(inSource, rh);
       } catch(JMSException jmse) {
         System.err.println("An exception occurred: "+jmse.getMessage());
         throw jmse;
       } catch (Exception ex) {
         System.err.println("An exception occurred: "+ex.getMessage());
         throw ex;
       }
     } else {
       System.out.println("There is no message in the queue: " + QUEUE);
       break;
     }
    }
  }

  /**
   * Runs this example from the command line.
   * <p>
   * Use this command:
   * <tt>java examples.jms.messageformat.ClientReceive t3://localhost:7001</tt>
   */
  public static void main(String[] args) throws Exception {
    if (args.length != 1) {
      System.out.println("Usage: java examples.jms.messageformat.ClientReceive WebLogicURL");
      return;
    }
    ClientReceive receiver = new ClientReceive();
    receiver.receive(args[0]);
  }
}