001 /*
002 * Copyright (C) The Apache Software Foundation. All rights reserved.
003 *
004 * This software is published under the terms of the Apache Software License
005 * version 1.1, a copy of which has been included with this distribution in
006 * the LICENSE file.
007 *
008 * $Id: Caller.java 155459 2005-02-26 13:24:44Z dirkv $
009 */
010 package org.apache.commons.messenger.tool;
011
012 import java.io.FileReader;
013 import java.io.FileWriter;
014 import java.io.InputStreamReader;
015 import java.io.OutputStreamWriter;
016 import java.io.PrintWriter;
017 import java.io.Reader;
018 import java.io.Writer;
019
020 import javax.jms.Destination;
021 import javax.jms.JMSException;
022 import javax.jms.Message;
023 import javax.jms.TextMessage;
024
025 import org.apache.commons.messenger.MessengerManager;
026
027 /** <p><code>Caller</code> is a sample program that
028 * sends a message to a destination and waits for a response.</p>
029 *
030 * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
031 * @version $Revision: 155459 $
032 */
033 public class Caller extends Producer {
034
035 public static void main(String[] args) {
036 try {
037 Caller client = new Caller();
038 client.run( args );
039 }
040 catch (JMSException e) {
041 System.out.println( "Caught: " + e );
042 Exception linked = e.getLinkedException();
043 if ( linked != null ) {
044 System.out.println( "Underlying exception: " + linked );
045 linked.printStackTrace();
046 }
047 else {
048 e.printStackTrace();
049 }
050 }
051 catch (Exception e) {
052 System.out.println( "Caught: " + e );
053 e.printStackTrace();
054 }
055 }
056
057 public void run(String[] args) throws Exception {
058 if ( args.length < 2 ) {
059 System.out.println( "Usage: Caller messengerName destination [inputFileName] [outputFileName]" );
060 System.out.println( "If no input file is used then System.in is used." );
061 System.out.println( "If no output file is used then System.out is used." );
062 return;
063 }
064 String name = args[0];
065 String subject = args[1];
066 messenger = MessengerManager.get( name );
067 if ( messenger == null ) {
068 throw new JMSException( "No such messenger called: " + name );
069 }
070 Destination destination = messenger.getDestination( subject );
071 if ( destination == null ) {
072 throw new JMSException( "Could not find destination: " + subject );
073 }
074
075 Reader reader = ( args.length > 2 )
076 ? new FileReader( args[2] )
077 : new InputStreamReader( System.in );
078
079 Writer writer = ( args.length > 3 )
080 ? new FileWriter( args[3] )
081 : new OutputStreamWriter( System.out );
082
083 call( destination, reader, writer );
084
085 // close the JMS connection to release any background threads
086 messenger.close();
087 }
088
089 protected void call( Destination destination, Reader reader, Writer writer ) throws Exception {
090 Message request = createMessage( reader );
091
092 Message response = messenger.call( destination, request );
093
094 writeMessage( response, writer );
095 }
096
097
098 /** Writes the given message to the Writer */
099 protected void writeMessage(Message message, Writer out) throws Exception {
100 PrintWriter writer = new PrintWriter(out);
101 if ( message instanceof TextMessage ) {
102 TextMessage textMessage = (TextMessage) message;
103 writer.println( textMessage.getText() );
104 }
105 writer.close();
106 }
107 }
108
109