WS-BPEL 2.0 Beginner's Guide

Understanding the BPEL language

Let's now have a more detailed look into what we did and try to understand what a BPEL process is. A BPEL process is basically a piece of source code with the .bpel extension, which is executed on a process server. BPEL uses the XML vocabulary to write the code. So far, we have used the visual editor to compose the BPEL process. However, we can switch to the source code view.

A BPEL process consists of steps. Each step is called an activity. BPEL supports basic and structured activities. Basic activities represent basic constructs and are used for common tasks listed, as follows:

• Invoking other web services using <invoke>
• Waiting for the client to invoke the business process through sending a message using <receive> ...