Time for action – declaring the cancel operation on the BPEL process interface

To add the cancel operation to the BPEL process WSDL interface, we will proceed as follows:

1. We will open the BookWarehousingBPEL.wsdl interface.
2. We will scroll down to the declaration of the BookWarehousingBPEL port type. We can see that the port type specifies a single process operation:
   
3. We will add the cancel operation, which the client will use to cancel the running BPEL instance. In our example, we will use the same input message as in the process operation:
   
4. Next, we will add the cancel operation as the trigger for the OnEvent event handler. We will open the BookWarehousingBPEL.bpel process and double click on the OnEvent activity.
5. A window will pop up, where we will specify the partner link, port type, and operation name. We will specify the client partner link, the BookWarehousingBPEL port type, and the cancel operation. For the variable, we will type the cancelInputMessage name and select Message Type...