/*
* Copyright (C) 2000, O'Reilly & Associates, Inc.
* The code in this file may be copied, distributed, and reused,
* provided that you do not remove this copyright notice.
* O'Reilly & Associates assumes no responsibility for damages
* resulting from the use of this code.
*/
package chap5.b2b;
import java.util.StringTokenizer;
import java.util.Properties;
//import javax.naming.InitialContext;
import javax.jms.TopicConnectionFactory;
import javax.jms.QueueConnectionFactory;
import javax.jms.Topic;
import javax.jms.Queue;
import javax.jms.QueueReceiver;
import javax.jms.Session;
import javax.jms.TextMessage;
public class QWBrowser implements javax.jms.MessageListener{
private javax.jms.TopicConnection tConnect = null;
private javax.jms.TopicSession tSession = null;
private javax.jms.TopicPublisher tPublisher = null;
private javax.jms.QueueConnection qConnect = null;
private javax.jms.QueueSession qSession = null;
private javax.jms.QueueReceiver qReceiver = null;
private javax.jms.Queue receiveQueue = null;
private javax.jms.Topic hotDealsTopic = null;
private javax.jms.TemporaryTopic buyOrdersTopic = null;
private String uname = null;
public QWBrowser (String broker, String username, String password){
try{
TopicConnectionFactory tFactory = null;
QueueConnectionFactory qFactory = null;
InitialContext jndi = null;
uname = username;
Properties env = new Properties();
// ... specify the JNDI properties specific to JNDI SPI being used
env.put("BROKER",broker);
jndi = new InitialContext(env);
tFactory =
(TopicConnectionFactory)jndi.lookup("TopicConnectionFactory");
qFactory =
(QueueConnectionFactory)jndi.lookup("QueueConnectionFactory");
tConnect = tFactory.createTopicConnection (username, password);
qConnect = qFactory.createQueueConnection (username, password);
tSession =
tConnect.createTopicSession(false,Session.AUTO_ACKNOWLEDGE);
qSession =
qConnect.createQueueSession(false,Session.AUTO_ACKNOWLEDGE);
hotDealsTopic = (Topic)jndi.lookup("Hot Deals");
receiveQueue = (Queue)jndi.lookup("Reply Q");
tPublisher = tSession.createPublisher(hotDealsTopic);
qReceiver = qSession.createReceiver(receiveQueue);
((progress.message.jclient.QueueReceiver)qReceiver).setPrefetchThreshold(0);
((progress.message.jclient.QueueReceiver)qReceiver).setPrefetchCount(1);
// Now that setup is complete, start the Connection
tConnect.start();
}catch (javax.jms.JMSException jmse){
jmse.printStackTrace(); System.exit(1);
}catch(javax.naming.NamingException jne){
jne.printStackTrace(); System.exit(1);
}
}
private void publishPriceQuotes(String dealDesc, String username,
String itemDesc, float oldPrice,
float newPrice){
try{
javax.jms.StreamMessage message = tSession.createStreamMessage();
message.writeString(dealDesc);
message.writeString(itemDesc);
message.writeFloat(oldPrice);
message.writeFloat(newPrice);
message.setStringProperty("Username", username);
message.setStringProperty("itemDesc", itemDesc);
message.setJMSReplyTo(receiveQueue);
tPublisher.publish(
message,
javax.jms.DeliveryMode.PERSISTENT,
javax.jms.Message.DEFAULT_PRIORITY,
1800000);
}catch ( javax.jms.JMSException jmse ){
jmse.printStackTrace();
}
}
public void onMessage( javax.jms.Message message){
try{
TextMessage textMessage = (TextMessage) message;
String text = textMessage.getText();
System.out.println("Order received - "+text+
" from " + message.getJMSCorrelationID());
}catch (java.lang.Exception rte){
rte.printStackTrace();
}
}
private int examineQueue(int inStockQty)
{
int cnt = 0;
int bestQty = 0;
try{
// qConnect.start();
System.out.println("In Stock QTY: " + inStockQty);
System.out.print ( "Creating QueueBrowser..." );
javax.jms.QueueBrowser browser
= qSession.createBrowser(receiveQueue);
System.out.println ("[done]");
java.util.Enumeration e = browser.getEnumeration();
while(e.hasMoreElements()){
System.out.print(" --> getting message "
+ String.valueOf(++cnt) + "...");
javax.jms.TextMessage message =
(javax.jms.TextMessage) e.nextElement();
System.out.println("[" + message.getText() + "]");
if (message != null){
int orderQty = message.getIntProperty("QTY");
if( orderQty > bestQty && orderQty <= inStockQty)
bestQty = orderQty;
}
}
// Free any resources in the browser.
browser.close();
}catch( javax.jms.JMSException jmse ){
jmse.printStackTrace();
}
System.out.println("\nBestQty: " + bestQty);
return bestQty;
}
public void processInput(){
try{
// Read all standard input and send it as a message.
java.io.BufferedReader stdin = new java.io.BufferedReader
(new java.io.InputStreamReader( System.in ) );
while ( true ){
System.out.println ("Enter: Item, Old Price, New Price ");
System.out.println("\ne.g. Bowling Shoes, 100.00, 55.00");
String dealDesc = stdin.readLine();
if(dealDesc != null && dealDesc.length() > 0){
// parse the deal description
StringTokenizer tokenizer =
new StringTokenizer(dealDesc,",") ;
String itemDesc = tokenizer.nextToken();
String temp = tokenizer.nextToken();
float oldPrice =
Float.valueOf(temp.trim()).floatValue();
temp = tokenizer.nextToken();
float newPrice =
Float.valueOf(temp.trim()).floatValue();
publishPriceQuotes(dealDesc,uname,
itemDesc, oldPrice,newPrice);
int inStockQty =
(int)(java.lang.Math.random() * (double)1000);
int bestQty = examineQueue(inStockQty);
qConnect.start();
javax.jms.TextMessage textMessage = null;
while( true )
{
textMessage =
(javax.jms.TextMessage)qReceiver.receive(1000);
if ( textMessage == null ){
qConnect.stop();
break; // no more messages to get
}
String text = textMessage.getText();
int qty = textMessage.getIntProperty("QTY");
System.out.println("\nOrder received - "+text+
" from " + textMessage.getJMSCorrelationID());
// could have missed the first one
if( qty > bestQty && qty <= inStockQty)
bestQty = qty;
if (qty == bestQty){
System.out.println("Fulfilling order");
// Do some processing to fulfill order
}else{
System.out.println("Placing in BACK-ORDER status");
// Do some processing to create BACK-ORDER status
}
}
}else{
this.exit();
}
}
}catch (javax.jms.JMSException jmse){
jmse.printStackTrace();
}catch( java.io.IOException ioe ){
ioe.printStackTrace();
//}catch( java.lang.InterruptedException ie ){
// ie.printStackTrace();
}
}
public void exit(){
try{
tConnect.close();
qConnect.close();
}catch (javax.jms.JMSException jmse){
jmse.printStackTrace();
}
System.exit(0);
}
public static void main(String argv[]) {
String broker, username, password;
if(argv.length == 3){
broker = argv[0];
username = argv[1];
password = argv[2];
}else{
System.out.println("Invalid arguments. Should be: ");
System.out.println("java QWholesaler broker username password");
return;
}
QWBrowser wholesaler = new QWBrowser(broker, username, password);
wholesaler.processInput();
}
}
class InitialContext
{
String mBroker = null;
public InitialContext (Properties env)
{
mBroker = env.getProperty("BROKER");
return;
}
public Object lookup(String str) throws javax.naming.NamingException,
javax.jms.JMSException
{
if ( str.equalsIgnoreCase("Hot Deals") )
return (new progress.message.jclient.Topic(str));
else if ( str.equalsIgnoreCase("Buy Order") )
return (new progress.message.jclient.Topic(str));
else if ( str.equalsIgnoreCase("Reply Q") )
return (new progress.message.jclient.Queue("SampleQ1"));
else if( str.equalsIgnoreCase("TopicConnectionFactory") )
return (new progress.message.jclient.TopicConnectionFactory (mBroker));
else if( str.equalsIgnoreCase("QueueConnectionFactory") )
return (new progress.message.jclient.QueueConnectionFactory (mBroker));
else // its whatever "Chat" topic was passed in on the command line
return (new progress.message.jclient.Topic(str));
}
} |
