Agent Request (Synchronous event delivery)

The Agent Request interaction pattern synchronously delivers a request message from the adapter to WebSphere Application Server and requires a response.

To create an Agent Request interaction pattern, you must create an Enterprise Application Archive application that contains:

The Enterprise Application Archive application must also contain .wsdl and .xsd files from the Service Project. If you chose Export to Service Project when you deployed your System Manager user project, the Service Project already exists and is included in the Enterprise Application Archive. If you instead exported your System Manager user project as individual files to a directory or as a JAR file, you will need to import the file or files into a new Service Project. To do so, follow the same procedure as described for an Agent Delivery interaction pattern, in Import files for a new service project.

The procedure for creating an Agent Request interaction pattern is similar to that for creating an Agent Delivery pattern, except that this pattern requires that a response message be sent. Accordingly, the business logic in the EJB skeleton for the Agent Request interaction pattern must return a value.

Perform the following steps to create an Agent Request interaction pattern.

Create an EJB project

The Agent Request interaction pattern requires an EJB to consume the message incoming to WebSphere Application Server from the agent. You must both create the EJB and add business logic to the EBJ method to process the received event.

Start by creating a project to contain the EJB:

  1. In the J2EE view of the Business Integration perspective, choose File>New>Project.
  2. In the New Project dialog, choose EJB in the left-hand panel, then select EJB project in the right-hand panel, and then choose Next.
  3. In the Select an EJB Version dialog, choose Create 2.0 EJB Project, and click Next.
  4. In the EJB Project Creation Dialog, provide a name for your EJB project (see Figure 37), and the name of a new or existing Enterprise Application Archive project folder to which it will be added. If you specify a name for a new Enterprise Application Archive project, a folder with that project name will be created.

    Figure 37. Naming the EJB project


  5. Choose Finish. A project, containing an EJB module, is generated under the name that you specified. The EJB project is created for you and you can see it in the J2EE Hierarchy view under EJB Modules. In the Services view, under Service Projects, select the .wsdl interface file that you imported from your connector configuration (for example, AgentReqConnector.wsdl). Right click, and choose New>Build from Service. The New Service Skeleton dialog opens.
  6. Choose EJB Service Skeleton (see Figure 27) and click Next.

    Figure 38. Choosing EJB Service Skeleton


  7. In the New Service Skeleton dialog, select Create a new port and binding and select Generate helper classes. Choose Next.
  8. The Service Skeleton dialog appears.
  9. Select the appropriate Port type name according to the interaction pattern you are creating, and provide a meaningful package name in place of the default. Click Next.
  10. In the next dialog, you can specify properties for generating the EJB skeleton, or accept the defaults. Click Finish. The newly created EJB project will be listed under Deployable Services in the Services view.
  11. Edit the skeleton to add any necessary business logic.

Create an MDB

A message driver bean is responsible for receiving events as messages from the connector and invoking EJB processing of the events.

In this step, you will deploy the EJB service to the server using existing inbound port and bindings - the original JMS bindings. This step generates an MDB that invokes the appropriate method of the Session Bean skeleton. The MDB is specific to the port type and the selection of the operation is made based on the incoming message properties: WSDLOperation (and possibly WSDLInput and WSDLOutput) properties. The additional helper classes, format handlers, are also generated during the deployment. These are used to convert from the wire format (the XML message) to the Java Class, which in turn is passed as an argument to the business method of the EJB.

You must configure the JNDI names uses by the EJB and MDB. The JNDI setup is necessary since the lookup names of the queue connection factory and queues defined in WSDL may not match the actual names defined on your server. The WebSphere Application Server allows you to map the name you are looking up (as specified in the .wsdl file) to the actual JNDI name deployed on the server, thus allowing correct execution without the need for modification of your wsdl files. You also need to specify what listener port is used by the MDB.

  1. In the Package Explorer view, expand the folder for the Service Project that you have created and select the EJBService .wsdl file that was generated in the previous task. Right-click on the file, and in the pop-up choose Enterprise Services>Generate Deploy Code.
  2. In the Generate Deploy Code dialog (see Figure 39), select Use an existing port. You can either select the same EJB project you created in the previous step (for the EJB skeleton) or specify the name of a new EJB project to create. A new EJB project must be in the same Enterprise Application Archive project as your existing EJB skeleton project. Choose Next.

    Figure 39. Generate Deploy Code dialog


  3. In the Inbound Service Files dialog, select the JMSService .wsdl file for your project, and the corresponding service name and port name. Choose Finish.
  4. In the J2EE Hierarchy view, select your project under EJB Modules, right-click, choose Open With the EJB Deployment Descriptor editor and choose the Bean tab. Verify that the Destination type is Queue. Specify the correct ListenerPort, so that its queue connection factory and queue match those specified in the .wsdl file for this interaction pattern.
  5. Choose the References tab. Select the resource queue name listed under the MDB. The name from the .wsdl file then appears in the Name box at right. Under WebSphere Bindings, in the JNDI name field, enter the correct JNDI name for the deployment of this queue, as defined in the WebSphere Application Server Administrative Console (see Figure 40).

    Figure 40. Entering the JNDI name for queue deployment


  6. Select the connector factory listed under the MDB. Under WebSphere Bindings,in the JNDI name field, enter the correct JNDI name for the deployment of this connection factory, as defined in the WebSphere Application Server Administrative Console (see Figure 41).

    Figure 41. Entering the JNDI name for connection factory


  7. Save the changes that you made in the EJB Deployment Descriptor editor.
  8. Open the Server Configuration tab in the lower panel of the Business Integration perspective and right-click on the Servers icon.
  9. Choose New, and choose Servers and Server Configuration. The Create a New Server and Server Configuration dialog appears.
  10. In the Server name field, enter a name for the server instance you are creating. Enter the same name in the Folderfield. In the Server Type field, select EE Test Environment.
  11. Choose Finish, and respond Yes when prompted to create a new server project with the name you specified.
  12. After the utility completes, in the Server Configuration panel double-click the icon for the new server instance that you have created. The WebSphere Server panel appears, with the name of the server instance you have created. Choose the Configuration tab.
  13. The WebSphere Server Configuration panel appears. Put a check in the Enable administration console check box.
  14. Choose the Variables tab. In the Defined variables drop down box, locate the MQ_INSTALL_ROOT variable. Change the value of the variable to the absolute root path of your MQ installation.
  15. Save your configuration. (Ctrl+S).
  16. Start the newly configured server instances, as follows: In the lower portion of the Business Integration perspective, choose the Servers tab. The Servers panel displays. In the Servers panel, select the icon for the newly configured server instance, and click the run button to start the server.
  17. Open the WebSphere Application Server Administrative Console. Under General Properties under the Configuration tab, add the listener port name that you specified in the Bean tab of EJB Deployment Descriptor (see Figure 42). Add the same connection factory JNDI value and destination JNDI queue name value that you specified in the References tab of EJB Deployment Descriptor. As appropriate for your needs, make any necessary changes in the Maximum sessions, Maximum retries, and Maximum messages fields.

    Figure 42. Adding the Listener Port and JNDI names


  18. In the WebSphere Application Server Administrative Console, add the queue as a resource (see Figure 43). Provide a display name for the queue, and use that same value in the Base Queue Name field. In the JNDI Name field, enter the name of the queue that you established in the destination JNDI queue name value in the Bean tab of EJB Deployment Descriptor.

    Figure 43. Adding the queue as a resource


    Provide a value for Base Queue Manager Name (see Figure 44).

    Figure 44. Providing a Base Queue Manager name


After you have completed these steps, you will have a completed Enterprise Application Archive application for this interaction pattern. You can then test this Enterprise Application Archive application in EE Test Environment and deploy the Enterprise Application Archive application to another WebSphere Application Server environment.

Copyright IBM Corp. 1997, 2004