queuebrowse.java

精通Java核心技术的随书源代码

// ==================== Program Discription ==========================
// 程序名称：示例17-3:QueueBrowse.java
// 程序目的：建立JMS队列连接并游览队列消息
// ==============================================================
package examples.jms.queue;

import java.io.*;
import java.util.*;
import java.util.Date;
import javax.transaction.*;
import javax.naming.*;
import javax.jms.*;

public class QueueBrowse
{
  public final static String JNDI_FACTORY="weblogic.jndi.WLInitialContextFactory";
  public final static String JMS_FACTORY="weblogic.examples.jms.QueueConnectionFactory";
  public final static String QUEUE="weblogic.examples.jms.exampleQueue";

  private QueueConnectionFactory qconFactory;
  private QueueConnection qcon;
  private QueueSession qsession;
  private QueueBrowser qbrowser;
  private Queue queue;

  public void init(Context ctx, String queueName) throws NamingException, JMSException
  {
    qconFactory = (QueueConnectionFactory) ctx.lookup(JMS_FACTORY);
    qcon = qconFactory.createQueueConnection();
    qsession = qcon.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
    queue = (Queue) ctx.lookup(queueName);
    qbrowser = qsession.createBrowser(queue);
    qcon.start();
  }

  public void displayQueue() throws JMSException
  {
    Enumeration e = qbrowser.getEnumeration();
    Message m = null;

    if (! e.hasMoreElements()) {
      System.out.println("There are no messages on this queue.");
    } else {
      System.out.println("Queued JMS Messages: ");
      while (e.hasMoreElements()) {
        m = (Message) e.nextElement();
        System.out.println("Message ID " + m.getJMSMessageID() + 
                           " delivered " + new Date(m.getJMSTimestamp()) + 
                           " to " + m.getJMSDestination());
        System.out.print("\tExpires        ");
        if (m.getJMSExpiration() > 0) {
          System.out.println( new Date( m.getJMSExpiration()));
            }
        else 
          System.out.println("never");
        System.out.println("\tPriority       " + m.getJMSPriority());
        System.out.println("\tMode           " + (
                      m.getJMSDeliveryMode() == DeliveryMode.PERSISTENT ? 
                                       "PERSISTENT" : "NON_PERSISTENT"));
        System.out.println("\tCorrelation ID " + m.getJMSCorrelationID());
        System.out.println("\tReply to       " + m.getJMSReplyTo());
        System.out.println("\tMessage type   " + m.getJMSType());
        if (m instanceof TextMessage) {
         System.out.println("\tTextMessage    \"" + ((TextMessage)m).getText() + "\"");
        }
      }
    }
  }

  public void close() throws JMSException
  {
    qbrowser.close();
    qsession.close();
    qcon.close();
  }

  public static void main(String[] args) throws Exception 
  {
    if (args.length != 1) {
      System.out.println("Usage: java examples.jms.queue.QueueBrowse WebLogicURL");
      return;
    }
    InitialContext ic = getInitialContext(args[0]);
    QueueBrowse qb = new QueueBrowse();
    qb.init(ic, QUEUE);
    qb.displayQueue();
    qb.close();
  }

  private static InitialContext getInitialContext(String url) throws NamingException 
  {
    Hashtable env = new Hashtable();
    env.put(Context.INITIAL_CONTEXT_FACTORY, JNDI_FACTORY);
    env.put(Context.PROVIDER_URL, url);
    return new InitialContext(env);
  }
}