001package var.mom.jms.chat; 002 003import java.io.BufferedReader; 004import java.io.IOException; 005import java.io.InputStreamReader; 006 007import javax.jms.Connection; 008import javax.jms.ConnectionFactory; 009import javax.jms.Destination; 010import javax.jms.JMSException; 011import javax.jms.Message; 012import javax.jms.MessageConsumer; 013import javax.jms.MessageListener; 014import javax.jms.MessageProducer; 015import javax.jms.Session; 016import javax.jms.TextMessage; 017import javax.naming.Context; 018import javax.naming.InitialContext; 019import javax.naming.NamingException; 020 021/** 022 * Chat Client using publish/subscribe on JMS provider Topic; represents user 023 * name as part of message payload 024 * 025 * @author Sandro Leuchter 026 * 027 */ 028public class ChatClient implements MessageListener { 029 private Connection connection; 030 private Session session; 031 private MessageProducer producer; 032 private MessageConsumer consumer; 033 034 /** 035 * constructor, establishes and starts connection to JMS provider specified in 036 * JNDI (via jndi.properties), afterwards producer and consumer are ready 037 * 038 * @param sendDest Destination for producer 039 * @param receiveDest Destination for consumer 040 * 041 * @throws NamingException JNDI exceptions 042 * @throws JMSException JMS exceptions 043 * @see javax.jms.Destination 044 */ 045 public ChatClient(String sendDest, String receiveDest) throws NamingException, JMSException { 046 Context ctx = new InitialContext(); 047 ConnectionFactory factory = (ConnectionFactory) ctx.lookup("ConnectionFactory"); 048 this.connection = factory.createConnection(); 049 this.session = this.connection.createSession(false, Session.AUTO_ACKNOWLEDGE); 050 Destination destOut = (Destination) ctx.lookup(sendDest); 051 Destination destIn = (Destination) ctx.lookup(receiveDest); 052 this.producer = this.session.createProducer(destOut); 053 this.consumer = this.session.createConsumer(destIn); 054 this.consumer.setMessageListener(this); 055 this.connection.start(); 056 } 057 058 /** 059 * asynchronous message consumption 060 * 061 * @see javax.jms.MessageListener 062 */ 063 @Override 064 public void onMessage(Message message) { 065 if (message instanceof TextMessage) { 066 TextMessage textMessage = (TextMessage) message; 067 try { 068 System.out.println(textMessage.getText()); 069 } catch (JMSException e) { 070 System.err.println(e); 071 } 072 } 073 } 074 075 /** 076 * main routine and starting point of program 077 * 078 * @param args[0] user name 079 */ 080 public static void main(String[] args) { 081 ChatClient node = null; 082 try { 083 node = new ChatClient("var.mom.jms.channel1", "var.mom.jms.channel1"); 084 BufferedReader input = new BufferedReader(new InputStreamReader(System.in)); 085 String line; 086 while (true) { 087 line = input.readLine(); 088 node.producer.send(node.session.createTextMessage(args[0] + "> " + line)); 089 } 090 } catch (NamingException | JMSException | IOException e) { 091 System.err.println(e); 092 } finally { 093 try { 094 if ((node != null) && (node.producer != null)) { 095 node.producer.close(); 096 } 097 if ((node != null) && (node.consumer != null)) { 098 node.consumer.close(); 099 } 100 if ((node != null) && (node.session != null)) { 101 node.session.close(); 102 } 103 if ((node != null) && (node.connection != null)) { 104 node.connection.close(); 105 } 106 } catch (JMSException e) { 107 System.err.println(e); 108 } 109 } 110 } 111}