/*

  * Copyright (C) The Apache Software Foundation. All rights reserved.

  *

  * This software is published under the terms of the Apache Software License

  * version 1.1, a copy of which has been included with this distribution in

  * the LICENSE file.

  * 

  * $Id: ConsumerTask.java 155459 2005-02-26 13:24:44Z dirkv $

  */

 package org.apache.commons.messenger.task;

 import java.io.File;

 import java.io.FileWriter;

 import java.io.IOException;

 import javax.jms.Destination;

 import javax.jms.JMSException;

 import javax.jms.Message;

 import javax.jms.TextMessage;

 import org.apache.commons.messenger.Messenger;

 import org.apache.commons.messenger.MessengerManager;

 import org.apache.tools.ant.BuildException;

 import org.apache.tools.ant.Project;

 import org.apache.tools.ant.Task;

 /** 

  * <p><code>ConsumerTask</code> is an Ant task which will 

  * publish all of the given text files as a JMS Text Message

  * using a given JMS Connection (Messenger) and a Destination

  *

  * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>

  * @version $Revision: 155459 $

  */

 public class ConsumerTask extends Task {

     private Messenger messenger;

     private String messengerName;

     private Destination destination;

     private String subject;

     private MessengerManager messengerManager;    

     /** the number of messages to receive */

     private int count;

     /** the output directory */

     private File dir = new File(".");    

     // Properties

     //-------------------------------------------------------------------------

     /** 

      * Sets the output directory 

      */

     public void setDir(File dir) {

         this.dir = dir;

     }

     public Messenger getMessenger() throws JMSException {

         if ( messenger == null ) {

             messenger = getMessengerManager().getMessenger( getMessengerName() );

         }

         return messenger;

     }

     /** Sets the Messenger to be used */

     public void setMessenger(Messenger messenger) {

         this.messenger = messenger;

     }

     /** Getter for property messengerName.

      * @return Value of property messengerName.

      */

     public String getMessengerName() {

         return messengerName;

     }

     /** Setter for property messengerName.

      * @param messengerName New value of property messengerName.

      */

     public void setMessengerName(String messengerName) {

         this.messengerName = messengerName;

     }

     /** Getter for property destination.

      * @return Value of property destination.

      */

     public Destination getDestination() throws JMSException {

         if ( destination == null ) {

             destination = getMessenger().getDestination( getSubject() );

         }

         return destination;

     }

     /** Setter for property destination.

      * @param destination New value of property destination.

      */

     public void setDestination(Destination destination) {

         this.destination = destination;

     }

     /** Getter for property subject.

      * @return Value of property subject.

      */

     public String getSubject() {

         return subject;

     }

     /** Setter for property subject.

      * @param subject New value of property subject.

      */

     public void setSubject(String subject) {

         this.subject = subject;

     }

     /** Getter for property messengerManager.

      * @return Value of property messengerManager.

      */

     public MessengerManager getMessengerManager() {

         return messengerManager;

     }

     /** Setter for property messengerManager.

      * @param messengerManager New value of property messengerManager.

      */

     public void setMessengerManager(MessengerManager messengerManager) {

         this.messengerManager = messengerManager;

     }

     /** 

      * Sets the URI of the Messenger.xml configuration document to use

      * to configure the messengers to use for this task.

      */

     public void setConfiguration(String uri) throws JMSException {

         setMessengerManager( MessengerManager.load( uri ) );

     }

     /** 

      * @return the number of messages to receive.

      * A number less than or equal to 0 will receive messages forever

      */

     public int getCount() {

         return count;

     }

     /** 

      * Setter for the number of messages to receive.

      * A number less than or equal to 0 will receive messages forever

      */

     public void setCount(int count) {

         this.count = count;

     }

     // Task interface

     //-------------------------------------------------------------------------

     /**

      * Performs the copy operation.

      */

     public void execute() throws BuildException {

         try {

             Messenger messenger = getMessenger();

             if ( messenger == null ) {

                 throw new BuildException("Must specify a valid Messenger", location );

             }

             Destination destination = getDestination();

             if ( destination == null ) {

                 throw new BuildException("Must specify a valid JMS Destination", location );

             }

             if ( count > 0 ) {

                 log( "Will wait until I receive: " + count + " messages and will write to directory: " + dir );

                 for ( int i = 0; i < count; i++ ) {

                     Message message = messenger.receive( destination );

                     processMessage( message );

                 }

                 log( "Finished." );

             }

             else {

                 log( "Infinite loop. Will write to directory: " + dir );

                 while (true) {

                     Message message = messenger.receive( destination );

                     processMessage( message );

                 }

             }

         }

         catch (IOException e) {

             log( "Caught exception: " + e, Project.MSG_ERR );

             throw new BuildException(e, location);

         }

         catch (JMSException e) {

             log( "Caught exception: " + e, Project.MSG_ERR );

             throw new BuildException(e, location);

         }

         finally {        

             try {

                 // close the JMS connection to release any background threads        

                 messenger.close();

             }

             catch (Exception e) {

                 // ignore close exceptions

             }

         }

     }

     /**

      * Processes a given message

      */

     protected void processMessage(Message message) throws IOException, JMSException {

         log( "Received message to: " + message );

         String text = null;

         if ( message instanceof TextMessage ) {

             TextMessage textMessage = (TextMessage) message;

             text = textMessage.toString();

         }

         else {

             // #### bit of a hack!!!

             // ideally we need an XML format for message persistence

             text = message.toString();

         }       

         processMessageText(text);

     }

     /** 

      * Writes the given text to a file

      */

     protected void processMessageText(String text) throws IOException {

         FileWriter writer = new FileWriter( dir );

         writer.write ( text );

         writer.close();

     }

 }