This sample demonstrate how you can write your own custom mediation in java by using the Class mediator to extend the mediation functionality.
- For a list of general prerequisites, see Prerequisites to Start the ESB Samples.
Building the sample
The XML configuration for this sample is as follows:
This configuration file
synapse_sample_380.xml is available in the
To build the sample
Start the ESB with the sample 380 configuration. For instructions on starting a sample ESB configuration, see Starting the ESB with a sample configuration.
The operation log keeps running until the server starts, which usually takes several seconds. Wait until the server has fully booted up and displays a message similar to "WSO2 Carbon started in n seconds."
Start the Axis2 server. For instructions on starting the Axis2 server, see Starting the Axis2 server.
Deploy the back-end service SimpleStockQuoteService. For instructions on deploying sample back-end services, see Deploying sample back-end services.
Executing the sample
The sample client used here is the Stock Quote Client, which can operate in several modes. For further details on this sample client and its operation modes, see Stock Quote Client.
To execute the sample client
Run the following command from the
Analyzing the output
When the client is run, you will see see the following discounted quote value on the client console.
When you have a look at the console running Synapse. You will see the original value and the discounted value for the requested quote as follows.
synapse_sample_380.xml, ESB hands over the request message to the specified endpoint, which sends it to the Axis2 server running on port 9000. But the response message is passed through the class mediator before sending it back to the client. Two parameters named "discountFactor" and "bonusFor" are passed to the instance mediator implementation class (i.e. samples.mediators.DiscountQuoteMediator) before each invocation. Code of the mediator implementation class is given below.
All classes developed for class mediation should implement the Mediator interface, which contains the mediate(...) method. mediate(...) method of the above class is invoked for each response message mediated through the main sequence, with the message context of the current message as the parameter. All the details of the message including the SOAP headers, SOAP body and properties of the context hierarchy can be accessed from the message context. In this sample, the body of the message is retrieved and the discount percentage is subtracted from the quote price. If the quote request number is less than the number specified in the "bonusFor" property in the configuration, a special discount is given.