This topic outlines how to write a mediation handler, add mediation
function to it, and prepare it for installation on an application server.
Before you begin
Before you start this task, you should have access to a Java programming
environment, and the Eclipse development environment (part of the Application
Server Toolkit, or AST, supplied with WebSphere Application Server.)
Why and when to perform this task
A mediation handler can be deployed. Each mediation handler executes
some specific message processing at runtime, for example transforming a message
format, or routing a message to a particular destination. A mediation handler
is a Java program framework, to which you add the code that performs the mediation
function. For more information about handlers, see Mediation handlers.
Your mediation handler class can be defined
either in a Java project or an EJB project (which is needed for the deployment
artefact.) Your programming and deployment artefacts can be separated in different
projects. The steps below are for an EJB project, but the steps are very similar
if you want to create a Java project, since you simply define a target server
for either a Java project or an EJB project and the server runtime plugin
sets the classpath correctly.
Steps for this task
- Create a new EJB project:
- Switch to the J2EE perspective to work with J2EE projects. Click Window
> Open Perspective > Other >J2EE.
- From the File menu, select New > Project.
- Expand the J2EE folder, and select Enterprise Application Project.
Click Next.
- Optional: If you have created a Java project instead
of an EJB project, right click on the Java project folder icon for the context
menu and select Properties. When the Properties panel appears, select the
Server properties and target the WebSphere Application Server v6.0, as in
the next step.
- Enter a name for the project and target the project to WebSphere
Application Server v6.0. (If this is the first time you target this server
you will need to click the New... button.) Click Next to
take you to the EAR Module Projects window.
- Click New Module....
- Create a new module project by selecting the check box against
EJB project, and entering the name of your mediation handler.
- Click Finish. You are
returned to the EAR Module Projects window.
- Click Finish to create the new project.
- Create a mediation handler class by implementing the com.ibm.websphere.sib.mediation.handler.MediationHandler
interface.
- From the File menu, select New > Java Class.
- Specify the source folder for your mediation EAR project.
- Specify a name for your mediation handler.
- Select Superclass java.lang.Object.
- Select Interface com.ibm.websphere.sib.mediation.handler.MediationHandler.
- Click in the check box to select Inherited abstract methods
- Click Finish to create the new mediation
handler class.
- Add functional code that transforms or routes messages to your
mediation handler using the Application Server Toolkit (AST). For more information,
see Adding mediation function to handler code. Beware that the
default return value for the handle method created by the toolkit is false,
which causes the message to be discarded. You need to change the return value
to true to preserve the message.
- Prepare your mediation handler for installation into the application
server. Follow the instructions in the topic entitled "Deploying a mediation
handler" in the AST infocenter. Note that AST is also
available in the Rational Software Development Platform.
Next, you are ready to install your mediation handler into the application
server.