The following article describes a simple, JMS based, dynamic messaging routing solution using the Sun Java CAPS suite. Although the example if simple it is also scalable and works in all the environments I have used. The primary reason for this blog is so that I can describe in a future blog how to implement this using the new Java CAPS 6 environment and what the key differences are. This said the solution described in this article will build and run within the Java CAPS 6 Classic environment.

Resources

• 5.1.3 Project Export

Message Based Routing

The message based routing Java Collaboration (JCD) stores all its routing information within the "msgRouter.properties" file that must exist within the classpath for the server and the simplest solution to this is to place the file in the domains lib/classes directory. On first startup the JCD will read the contents of the properties file into a local Properties variable, "msgRouterProperties", which it will query later in the code to identify the required destination. This particular example will route the messages based on a JMS User property and hence does not need to know anything about the message structure or content. I would recommend that this structure always be used and if you require message based routing then add another JCD that unmarshals the message and sets the appropriate JMS property then passes then messages onto the Routing JCDs inbound queue.

You can see from the code below that the JCD initially obtains the default Message Server and Queue name to be used in the event that the routing property value can not be found in the properties file. If the default properties are not found within the properties file then the JCD will default to the Message Server and Queue Name defined in the Connectivity Map and Deployment profile.

The JCD will then attempt to obtain the Message Routing Property (TPPROPERTY) and subsequently the specific Message Server and Queue name matching that property:

• Message Server : <Routing Value>.msgServerURL
• Queue Name : <Routing Value>.queueName

Once these values have been obtained or the default values used if they do not exist then the outbound JMS Connections Message Server URL is set and the message is sent to the appropriate destination. The actual destination type, Queue or Topic, is set within the Connectivity Map. Once the message has been sent then the connection URL is reset to the default value for the next invocation.

JCD Code

public class jcdMsgRouter {     public com.stc.codegen.logger.Logger logger;     public com.stc.codegen.alerter.Alerter alerter;     public com.stc.codegen.util.CollaborationContext collabContext;     public com.stc.codegen.util.TypeConverter typeConverter;     private static final java.util.Properties msgRouterProperties = new java.util.Properties();     private static final String TPPROPERTY = "TRADING-PARTNER";     public void receive( com.stc.connectors.jms.Message input, com.stc.connectors.jms.JMS jmsOut )         throws Throwable     {         String msgServerURL = null;         String queueName = null;         String tpName = null;         String defaultMsgServerURL = null;         String defaultQueueName = null;         try {             // Load Properties if required             if (msgRouterProperties.isEmpty()) {                 java.io.InputStream propIS = this.getClass().getClassLoader().getResourceAsStream( "msgRouter.properties" );                 if (propIS != null) {                     msgRouterProperties.load( propIS );                     logger.info( "*** APH-I1 : Loading msgRouter.properties" );                 } else {                     logger.info( "*** APH-I2 : Can not find msgRouter.properties" );                 }             }             // Trading Partner Message Property             for (int i1 = 0; i1 < input.countUserProperty(); i1 += 1) {                 if (TPPROPERTY.equals( input.getUserProperty( i1 ).getName() )) {                     tpName = (String) input.getUserProperty( i1 ).getValue();                     break;                 }             }             if (tpName != null && !msgRouterProperties.isEmpty()) {                 if (defaultMsgServerURL == null) {                     defaultMsgServerURL = msgRouterProperties.getProperty( "default.msgServerURL" );                     defaultQueueName = msgRouterProperties.getProperty( "default.queueName" );                 }                 msgServerURL = msgRouterProperties.getProperty( tpName + ".msgServerURL", defaultMsgServerURL );                 queueName = msgRouterProperties.getProperty( tpName + ".queueName", defaultQueueName );                 // Log                 logger.info( "*** APH-I1 : msgServerURL = " + msgServerURL );                 logger.info( "*** APH-I1 : queueName = " + queueName );                 // Set JMS Params                 if (msgServerURL != null) {                     if (defaultMsgServerURL == null) {                         defaultMsgServerURL = jmsOut.getMessageServerURL();                     }                     jmsOut.setMessageServerURL( msgServerURL );                 }                 if (queueName != null) {                     jmsOut.sendTo( input, queueName );                 } else {                     jmsOut.send( input );                 }             } else {                 throw new Exception( "TP Name" + tpName + " does not exist or no valid properties" );             }         } catch ( Exception e ) {             logger.warn( "*** APH-I3 : Failed to send message", e );             if (msgServerURL != null && defaultMsgServerURL != null) {                 jmsOut.setMessageServerURL( defaultMsgServerURL );             }             jmsOut.sendTo( input, "TP_SEND_ERROR" );         } finally {             if (msgServerURL != null && defaultMsgServerURL != null && !msgServerURL.equals( defaultMsgServerURL )) {                 jmsOut.setMessageServerURL( defaultMsgServerURL );             }         }     } }

Properties File

default.msgServerURL=stcms://localhost:18007 default.queueName=qRouterOut partner1.msgServerURL=stcms://localhost:19007 partner1.queueName=qPartner1 partner2.msgServerURL=stcms://localhost:18007 partner2.queueName=qPartner2