Wholesalerpublic class Wholesaler extends Object implements javax.jms.MessageListener
| Fields Summary |
|---|
| private javax.jms.TopicConnection | connect | | private javax.jms.TopicSession | pubSession | | private javax.jms.TopicSession | subSession | | private javax.jms.TopicPublisher | publisher | | private javax.jms.TopicSubscriber | subscriber | | private javax.jms.Topic | hotDealsTopic | | private javax.jms.TemporaryTopic | buyOrdersTopic | | private boolean | topicRequestor | | private boolean | requestReplyReceive |
| Constructors Summary |
|---|
public Wholesaler(String broker, String username, String password)
try{
TopicConnectionFactory factory = null;
InitialContext jndi = null;
Properties env = new Properties();
// ... specify the JNDI properties specific to the JNDI SPI being used
env.put("BROKER", broker);
jndi = new InitialContext(env);
factory =
(TopicConnectionFactory)jndi.lookup("TopicConnectionFactory");
connect = factory.createTopicConnection (username, password);
connect.setClientID(username);
pubSession =
connect.createTopicSession(false,Session.AUTO_ACKNOWLEDGE);
subSession =
connect.createTopicSession(false,Session.AUTO_ACKNOWLEDGE);
hotDealsTopic = (Topic)jndi.lookup("Hot Deals");
publisher = pubSession.createPublisher(hotDealsTopic);
buyOrdersTopic = subSession.createTemporaryTopic();
subscriber = subSession.createSubscriber(buyOrdersTopic);
// The printed examples in Chapter 4 cover asynchronous pub/sub, synchronous request/reply using the
// TopicRequestor object, and synchronous request/reply without the use of the TopicRequestor object.
// This one example covers all three situations, and has the different functionality bracketed by
// the use of the "topicRequestor" and "requestReply" booleans.
// TopicRequestor and receive() do not require a message listener
if(!topicRequestor && !requestReplyReceive)
subscriber.setMessageListener(this);
connect.start();
}catch (javax.jms.JMSException jmse){
jmse.printStackTrace(); System.exit(1);
}catch(javax.naming.NamingException jne){
jne.printStackTrace(); System.exit(1);
}
|
| Methods Summary |
|---|
| public void | exit()
try{
connect.close();
}catch (javax.jms.JMSException jmse){
jmse.printStackTrace();
}
System.exit(0);
| | public static void | main(java.lang.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 Wholesaler broker username password");
return;
}
Wholesaler wholesaler = new Wholesaler(broker, username, password);
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 ) );
System.out.println ("Enter: Item, Old Price, New Price ");
System.out.println("\ne.g. Bowling Shoes, 100.00, 55.00");
while ( true ){
String dealDesc = stdin.readLine();
if(dealDesc != null && dealDesc.length() > 0){
// parse the deal description
String itemDesc = null;
String temp = null;
float oldPrice = 0;
float newPrice = 0;
try {
StringTokenizer tokenizer =
new StringTokenizer(dealDesc,",") ;
itemDesc = tokenizer.nextToken();
temp = tokenizer.nextToken();
oldPrice =
Float.valueOf(temp.trim()).floatValue();
temp = tokenizer.nextToken();
newPrice =
Float.valueOf(temp.trim()).floatValue();
} catch ( java.util.NoSuchElementException e ) {
System.err.println( "Cannot parse deal descriptor " +
dealDesc );
continue;
} catch ( NumberFormatException e ) {
System.err.println( "Cannot parse deal descriptor " +
dealDesc );
continue;
}
wholesaler.publishPriceQuotes(dealDesc,username,
itemDesc, oldPrice,newPrice);
}else{
wholesaler.exit();
}
}
}catch( java.io.IOException ioe ){
ioe.printStackTrace();
}
| | public void | onMessage(javax.jms.Message message)
try{
TextMessage textMessage = (TextMessage) message;
String text = textMessage.getText();
System.out.println("\nOrder received - "+text+
" from " + message.getJMSCorrelationID());
}catch (java.lang.Exception rte){
rte.printStackTrace();
}
| | private void | publishPriceQuotes(java.lang.String dealDesc, java.lang.String username, java.lang.String itemDesc, float oldPrice, float newPrice)
try{
javax.jms.StreamMessage message = pubSession.createStreamMessage();
message.writeString(dealDesc);
message.writeString(itemDesc);
message.writeFloat(oldPrice);
message.writeFloat(newPrice);
message.setStringProperty("Username", username);
message.setStringProperty("Itemdesc", itemDesc);
message.setJMSReplyTo(buyOrdersTopic);
// The printed examples in Chapter 4 cover asynchronous pub/sub, synchronous request/reply using the
// TopicRequestor object, and synchronous request/reply without the use of the TopicRequestor object.
// This one example covers all three situations, and has the different functionality bracketed by
// the use of the "topicRequestor" and "requestReply" booleans.
if(topicRequestor)
{
//System.out.println("\nInitiating Synchronous Request");
javax.jms.TopicRequestor requestor =
new javax.jms.TopicRequestor(pubSession, hotDealsTopic);
javax.jms.Message aMessage = requestor.request(message);
if (aMessage == null)
System.out.println("\nrequest() returned null");
else
System.out.println("\nRequest Sent, Reply Received!");
if (aMessage != null)
{
onMessage(aMessage);
}
return;
}
// Publish the message. If its an asynchronous pub/sub, the onMessage handler
// will get called automatically
// If its a synchronous request/reply via receive(), call onMessage directly
publisher.publish(
message,
javax.jms.DeliveryMode.PERSISTENT,
javax.jms.Message.DEFAULT_PRIORITY,
1800000);
if(requestReplyReceive)
{
javax.jms.Message aMessage = subscriber.receive();
if (aMessage == null)
System.out.println("\nreceive() returned null");
else
System.out.println("\nRequest Sent, Reply Received!");
if (aMessage != null)
{
onMessage(aMessage);
}
return;
}
}catch ( javax.jms.JMSException jmse ){
jmse.printStackTrace();
}
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