Package examples.xml.messageformat

This example demonstrates how to use Message-driven beans to implement a simple stock-trading scenario in which the stock data is sent as an XML document.

See:
Description

Class Summary

ClientReceive	This class shows how to establish a connection to and receive messages from a JMS queue.
ClientSend	This class asks the user to input data to define a stock trade transaction.
MessageTraderBean	This class reads the XML data from a JMS queue, parses it and and calls the statefulSession.TraderBean EJB to actually perform the stock trade transaction.
RequestHandler	This class extends HandlerBase and is used to handle events created as an XML document is parsed by a SAX compliant parser.

Package examples.xml.messageformat Description

This example demonstrates how to use Message-driven beans to implement a simple stock-trading scenario in which the stock data is sent as an XML document.

The example illustrates how to:

• generate stock trade data as an XML file and send it to a JMS queue to await further processing.
• use a Message-driven bean to first parse the XML file using a SAX parser and then operate on TraderBean (a stateful Session EJB created in the EJB examples) to execute the stock trade.
• pass the resulting stock trade information in form of XML data to a different JMS queue.
• have a Client receive the data from the second JMS queue, parse it with a SAX parser, and print the final result of the trade.

Overview of the Example

To get the most out of this example, first read through the source code files.

• Client applications
  ClientSend.java - client application that sends XML data to a JMS queue.
  ClientReceive.java - client application that receives XML data from a JMS queue.

  XML parsing event handler

  RequestHandler.java - class that handles the events created as the XML document is parsed in the MessageTraderBean Message-driven EJB.

  Deployment

  ejb-jar.xml - describes the MessageTraderBean Message-driven EJB.

  weblogic-ejb-jar.xml - describes how to deploy the MessageTraderBean Message-driven EJB.

  Message-Driven Bean

  MessageTraderBean.java

Start with the XML deployment files ejb-jar.xml and weblogic-ejb-jar.xml to find the general structure of the MessageTraderBean Message-driven EJB, then look at the ClientSend and the ClientReceive code to see how the application works.

Building and Running this Example

The XML examples included in the WebLogic Server 6.0 distribution are not shipped pre-built. To run these examples, you must first build them by following the instructions in this section.

The following section describes how to build and run the example:

1. Build the example
2. Configure the WebLogic server
3. Run the example

Build the example

1. Build and deploy the TraderBean EJB from the stateful Session EJB example.

2. Set up your development shell as described in Setting up your environment.

3. Add the xmlx.jar file located in the %WL_HOME%\lib directory to your CLASSPATH, where %WL_HOME% refers to the WebLogic Server installation directory.

4. Compile the example by executing the Java ant command. The Java ant command uses the build.xml file, located in the samples/examples/xml/messageformat directory, to build the example.

   The Java ant command builds the example and copies the files to the following directories of the WebLogic Server:

   • Client files: to /config/examples/clientclasses
   • EJBs: to /config/examples/applications/xml_messageformat.jar

   The WebLogic server automatically deploys the EJB as soon as the build command copies the EJB files to the correct directory. If the WebLogic server is not running, the EJB is deployed as soon as you start the WebLogic server.

Configure the WebLogic Server

1. Start the WebLogic Server.
2. Invoke the Administration Console in your browser.
3. Click to expand the Services node in the left pane and expand the JMS node.
4. Click to expand the Servers node.
5. Click to expand the examplesJMSServer node.
6. Right-click the Destinations node and choose Configure a new JMSQueue from the drop-down list.
7. Enter exampleQueueReceive in the Name textfield.
8. Enter weblogic.examples.jms.exampleQueueReceive in the JNDIName textfield.
9. Click Create.
10. Right-click the Destinations node and choose Configure a new JMSQueue from the drop-down list.
11. Enter exampleQueueSend in the Name textfield.
12. Enter weblogic.examples.jms.exampleQueueSend in the JNDIName textfield.
13. Click Create.
14. Click the Connection Factories node under the JMS node in the left pane.
15. Click exampleQueue.
16. Click the Targets tab in the right panel.
17. Move examplesServer to the Chosen list box, if not already there.
18. Click Apply.
19. Click to expand the Deployments node in the left pane and select EJB. A list of deployed EJBs displays.
20. Click the xml_messageformat deployment unit from the list.
21. Click the Targets tab in the right-hand pane.
22. Move examplesServer to the Chosen list box, if not already there.
23. Click Apply.

Run the Example

1. Start the WebLogic Server in a new command shell.

2. In your development shell, run the ClientSend client with the following command:

     $ java examples.xml.messageformat.ClientSend t3://hostname:port

   where:

   hostname

   Host name of the WebLogic Server.

   port

   Port where the WebLogic Server is listening for connections (weblogic.system.ListenPort).

3. Enter whether you want to buy or sell shares of BEAS or MSFT.

   You should see output similar to the following sample:

   Action ("Buy" or "Sell", "quit" to quit): buy
   Symbol ("BEAS" or "MSFT", "quit" to quit): BEAS
   Number of shares ("quit" to quit): 56
   Sending trade information...
   Your message has been sent to queue
   

   Check the shell from which you started the WebLogic server for the XML file that was sent to the JMS queue.

4. Run the ClientRecieve with the following command:

     $ java examples.xml.messageformat.ClientReceive t3://hostname:port

   You should see output similar to the following sample:

   START DOCUMENT
   
       ELEMENT: traderesult
   
          ATTR: action = bought
   
          ATTR: symbol = BEAS
   
          ATTR: numShares = 56
   
          ATTR: price = 100.0
   
          ATTR: changeInAccount = -5600.0
   
       END_ELM: traderesult
   
   END DOCUMENT
   
   setSessionContext called
   ejbCreate called
   buy (Erin, BEAS, 56)
   ejbRemove called
   
   There is no message in the queue: weblogic.examples.jms.exampleQueueReceive

There's More...

Read more about:

• XML in Programming WebLogic XML.

• EJB in BEA WebLogic Server Enterprise Java Beans.

• JMS in Programming WebLogic JMS.