Introduction

WebSphere Business Integration Server Foundation Process Choreographer leverages the Web Services Invocation Framework (WSIF) capability to invoke services. This article focuses on how you can define simple services with a Java Message Service binding and get a useful side effect -- the ability to send a simple message to a queue. In other words, you can send a message to a queue without developing any Java code.

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Getting started

This article presumes that WebSphere Studio Application Developer Integration Edition V5.1.1 is installed in your workstation and you are familiar with process development using Business Process Execution Language for Web Services (BPEL4WS) or (hereafter known as BPEL).

You also need to download the JMSReader.jar file included in the Download section later in this article.

In this article, you will work within an existing Service project that contains a basic process (see Figure 1):

Keep in mind that you need to change the process interface to obtain a one-way operation. In other words, delete the output parameter from the default "InputOperation".

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Creating the Web Service Definition Language

In this section, we'll define a service that defines our interface against the messaging middleware. In general, sending a message on queue is an asynchronous activity. In a service view, it corresponds to a one-way operation (with only an input or output message).

To create a new Web Service Definition Language (WSDL), you need to launch the wizard and Create an empty service by following these steps:

1. Select File => New => Empty Service.
2. In the dialog: insert these values:
1. Package: service (You can use another name for the value, but it is better if it is different from the process package)
2. File name: JMSService (Again, you can use another name for the value.)
3. Click Finish.
   The WSDL editor is opened on the previously created empty service.

Create a port type, an operation, and an input message as in Figure 2. The message is really simple -- it just contains one part defined as a String.

In the WSDL editor, follow these steps:

1. In the Port Type pane, right-click and select Add Child => Port Type.
2. In the dialog, insert JMSService as port type name.
3. Right-click the JMSService port type and select Add Child => Operation.
4. In the dialog, insert send as operation name.
5. Right-click the send operation and select Add Child => Input.
6. Right-click the input and select Set Message
7. In the dialog, insert SimpleMessage as message name.
8. In the Message pane, right-click SimpleMessage and select Add Child => Part.
9. In the dialog, insert Part as part name. By default the part type is xsd:string.

To add the JMS binding:

1. In the Binding pane, right-click and select Add Child => Binding.
2. In the dialog box, add the the following values:
1. Name: JMSBinding
2. Port Type: tns:JMSPortType
3. Protocol: JMS
4. Message type: TextMessage
3. Click Finish.

Create a new service called JMSService:

1. In the services pane, right-click and select Add Child => Service.
2. Right-click and select Add Child => Port to add a Port to the JMSService.
3. Populate the wizard with the following values:
1. Name: JMSPort
2. Binding: tns:JMSBinding
3. Protocol: JMS
4. JNDI connection factory name: jms/QCF
5. JNDI destination name: jms/Queue
6. JNDI provider URL: iiop://localhost:2809
   
   Figure 4. The port wizard
   
   
4. Click Finish.
5. Click Save to save the file.

The WSDL should display as in Figure 5:

Using JMS service in the process

Before using this service in the process, you need to generate the helper classes. This is required for two reasons:

1. To create Java Beans for all XML Schema Definitions found in .wsdl and .xsd files, referred to as data-type beans.
2. To create Java Beans to handle the serialization and deserialization of a data-type bean's wire format, referred to as format handler.

To invoke the wizard that generates the helper classes:

1. From the Services view, select the JMSService.wsdl.
2. From the toolbar, click the Generate helper classes button.
3. Click Ok in the information dialog box.

Now, you can drag and drop the WSDL file inside your BPEL process to add a partner link that describes the process interface toward the messaging middleware. A simple dialog box displays that requires you to click OK.

In the process, you need to add an invoke activity to send the JMS message. From the BPEL editor, perform the following steps:

1. Add an invoke activity.
2. Select the Implementation tab.
3. For Partner Link, select JMSPortType.
4. For Operation, select send.
5. Click New beside the Request property and enter SimpleMessage as the name of this process variable.

Now, you can use an assign activity to pass the value of InputVariable to SimpleMessage. Set the activity links to make the process appear as in Figure 7.

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Deploying the process

Before deploying the process, you have to change the server configuration.

1. From the server configuration editor, switch to the JMS tab and create a new queue named Queue (see Figure 8).
   Figure 8. JMS Server Properties
   
   
2. Make sure that JNDI connection factory named jms/QCF is defined (see Figure 9).
   Figure 9. The JMS Connection Factories section
   
   
3. From the JMS Destination section, click Add to create a JNDI destination.
4. Fill in the following values for Name JNDI Name: Queue and jms/Queue.
   Figure 10. The JMS Destinations section
   
   
5. Save and close the server configuration.
6. Perform the usual steps to generate the deploy code for the process.

The JMSReader servlet

To simplify the test, a simple servlet (JMSReader) that receives a message from the queue is available with this article. To use it, import the jar in the Web project and declare it inside the Web deployment descriptor.

A servlet is a Java object that is called by an HTTP request. This implies that to run a servlet you need to write the related URL in a browser. In WebSphere Studio Application Developer Integration Edition, a servlet can be hosted only by a Web project.

For the purpose of testing, it is possible use the Web project that was generated by the process deployment (the Web project name is composed by the service project name plus the "quotWeb"suffix).

1. From the File menu, select Import.
2. In the dialog box select Zip file.
3. Click Next.
4. Click Browse and select the JMSReader.jar file included with this article to populate the From zip file field.
5. Click Browse, find the Web project, and select the JavaSource folder to fill the Into folder field.
6. Click Finish
7. From J2EE Hierarchy view, double-click the Web project, the deployment descriptor displays in a new window.
8. Select the Servlets tab and click Add.
9. In the Add Servlet or JSP dialog box, select JMSReader.
10. Click OK.
11. In the URL Mapping section, click Add.

The Web deployment Descriptor should appear as in Figure 11:

The URL to invoke the servlet is so comprised of the following:

• Protocol, server, port: http://localhost:9080/
• Web project context root (by default the project name)
• The mapped URL for the servlet: /JMSReader

You should enter: http://localhost:9080/ProcessWeb/JMSReader.

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Conclusion

Now you can send a simple JMS messages inside a BPEL process using an elegant and quite simple approach. Under this pretext, this article reveals the power of WSIF technology inside the Business Process Choreographer. Nevertheless, if you want to send a specific complex message, you need write some lines of code!

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Download

Description	Name	Size	Download method
JMSReader.zip file	JMSReader.zip	2 KB	FTP|HTTP

Information about download methods

Resources

• Visit the WebSphere Business Integration Server Foundation information center for comprehensive help on Developing applications for BPEL-based processes.
  
  
• Visit the WebSphere Business Integration zone for Business Integration resources.
  
  
• Share your questions and views on this article with the author and other readers in the WebSphere Studio Application Developer Integration Edition forum
  
  
• Browse for books on these and other technical topics.
  
  
• Redbook: WebSphere Business Integration Server Foundation V5.1 Handbook
  
  
• Web Services Invocation Framework Web site.
  
  
• Process Execution Language for Web Services (BPEL4WS) specification -- Public draft Version 1.1 from a cross-industry workgroup.
  
  
• Getting started with BPEL4WS in WebSphere Studio -- A good introduction article to BPEL4WS in WebSphere Studio Application Developer Integration Edition.
  
  

About the author

Donato Marrazzo has worked for IBM Italy since 1999 and currently works as a WebSphere Technical Sales IT Specialist. He helps IBM clients and business partners design and implement solutions based on WebSphere products. Donato's areas of specialization include J2EE, Process Choreographer, and Web Services. Before joining the IBM Software Group, he spent three years consulting in J2EE and Portal solutions development. He is co-author of a forthcoming IBM redbook on SOA and J2EE. He earned a Masters degree in Computer Engineering from the Politecnico di Milano.

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Table of contents

• Introduction
• Getting started
• Creating the Web Service Definition Language
• Deploying the process
• Conclusion
• Download
• Resources
• About the author
• Comments

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