/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2009, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.classic.net;
  
  import java.io.Serializable;
  
  import javax.jms.ObjectMessage;
  import javax.jms.Queue;
  import javax.jms.QueueConnection;
  import javax.jms.QueueConnectionFactory;
  import javax.jms.QueueSender;
  import javax.jms.QueueSession;
  import javax.jms.Session;
  import javax.naming.Context;
  
  import ch.qos.logback.classic.spi.ILoggingEvent;
  import ch.qos.logback.core.AppenderBase;
  import ch.qos.logback.core.net.JMSAppenderBase;
  import ch.qos.logback.core.spi.PreSerializationTransformer;
  
  /**
   * A simple appender that publishes events to a JMS Queue. The events are
   * serialized and transmitted as JMS message type {@link
   * javax.jms.ObjectMessage}.
   * <p>
   * For more information about this appender, please refer to:
   * http://logback.qos.ch/manual/appenders.html#JMSQueueAppender
   * 
   * @author Ceki G&uuml;lc&uuml;
   */
  public class JMSQueueAppender extends JMSAppenderBase<ILoggingEvent> {
  
    static int SUCCESSIVE_FAILURE_LIMIT = 3;
  
    String queueBindingName;
    String qcfBindingName;
    QueueConnection queueConnection;
    QueueSession queueSession;
    QueueSender queueSender;
  
    int successiveFailureCount = 0;
  
    private PreSerializationTransformer<ILoggingEvent> pst = new LoggingEventPreSerializationTransformer();
    
    public JMSQueueAppender() {
    }
  
    /**
     * The <b>QueueConnectionFactoryBindingName</b> option takes a string value.
     * Its value will be used to lookup the appropriate
     * <code>QueueConnectionFactory</code> from the JNDI context.
     */
    public void setQueueConnectionFactoryBindingName(String qcfBindingName) {
      this.qcfBindingName = qcfBindingName;
    }
  
    /**
     * Returns the value of the <b>QueueConnectionFactoryBindingName</b> option.
     */
    public String getQueueConnectionFactoryBindingName() {
      return qcfBindingName;
    }
  
    /**
     * The <b>QueueBindingName</b> option takes a string value. Its value will be
     * used to lookup the appropriate <code>Queue</code> from the JNDI context.
     */
    public void setQueueBindingName(String queueBindingName) {
      this.queueBindingName = queueBindingName;
    }
  
    /**
     * Returns the value of the <b>QueueBindingName</b> option.
     */
    public String getQueueBindingName() {
      return queueBindingName;
    }
  
    /**
     * Options are activated and become effective only after calling this method.
     */
    public void start() {
      QueueConnectionFactory queueConnectionFactory;
  
      try {
        Context jndi = buildJNDIContext();
  
        // addInfo("Looking up [" + qcfBindingName + "]");
       queueConnectionFactory = (QueueConnectionFactory) lookup(jndi,
           qcfBindingName);
       // addInfo("About to create QueueConnection.");
       if (userName != null) {
         this.queueConnection = queueConnectionFactory.createQueueConnection(
             userName, password);
       } else {
         this.queueConnection = queueConnectionFactory.createQueueConnection();
       }
 
       // addInfo(
       // "Creating QueueSession, non-transactional, "
       // + "in AUTO_ACKNOWLEDGE mode.");
       this.queueSession = queueConnection.createQueueSession(false,
           Session.AUTO_ACKNOWLEDGE);
 
       // addInfo("Looking up queue name [" + queueBindingName + "].");
       Queue queue = (Queue) lookup(jndi, queueBindingName);
 
       // addInfo("Creating QueueSender.");
       this.queueSender = queueSession.createSender(queue);
 
       // addInfo("Starting QueueConnection.");
       queueConnection.start();
 
       jndi.close();
     } catch (Exception e) {
       addError("Error while activating options for appender named [" + name
           + "].", e);
     }
 
     if (this.queueConnection != null && this.queueSession != null
         && this.queueSender != null) {
       super.start();
     }
   }
 
   /**
    * Close this JMSAppender. Closing releases all resources used by the
    * appender. A closed appender cannot be re-opened.
    */
   public synchronized void stop() {
     // The synchronized modifier avoids concurrent append and close operations
     if (!this.started) {
       return;
     }
 
     this.started = false;
 
     try {
       if (queueSession != null) {
         queueSession.close();
       }
       if (queueConnection != null) {
         queueConnection.close();
       }
     } catch (Exception e) {
       addError("Error while closing JMSAppender [" + name + "].", e);
     }
 
     // Help garbage collection
     queueSender = null;
     queueSession = null;
     queueConnection = null;
   }
 
   /**
    * This method called by {@link AppenderBase#doAppend} method to do most
    * of the real appending work.
    */
   public void append(ILoggingEvent event) {
     if (!isStarted()) {
       return;
     }
 
     try {
       ObjectMessage msg = queueSession.createObjectMessage();
       Serializable so = pst.transform(event);
       msg.setObject(so);
       queueSender.send(msg);
       successiveFailureCount = 0;
     } catch (Exception e) {
       successiveFailureCount++;
       if (successiveFailureCount > SUCCESSIVE_FAILURE_LIMIT) {
         stop();
       }
       addError("Could not send message in JMSQueueAppender [" + name + "].", e);
 
     }
   }
 
   /**
    * Returns the QueueConnection used for this appender. Only valid after
    * start() method has been invoked.
    */
   protected QueueConnection getQueueConnection() {
     return queueConnection;
   }
 
   /**
    * Returns the QueueSession used for this appender. Only valid after start()
    * method has been invoked.
    */
   protected QueueSession getQueueSession() {
     return queueSession;
   }
 
   /**
    * Returns the QueueSender used for this appender. Only valid after start()
    * method has been invoked.
    */
   protected QueueSender getQueueSender() {
     return queueSender;
   }
 }