Command design pattern

WebSphere Commerce Server accepts requests from browser-based thin-client applications; and remote applications. For example, a request may come from a remote procurement system, or from another commerce server.

All requests, in their variety of formats, are translated into a common format by the controller layer. Once the requests are in this common format, they can be understood by WebSphere Commerce commands.

Commands implement the business rules of your site. There are two types of commands:

Controller commands
These implement business tasks such as user registration and allocation of inventory. Use these to implement high-level process logic for the business task.
Task commands
These implement discrete pieces of a business task such as address verification or ensuring passwords comply to the defined password policies. For example, during executing of the Registration controller command a callout may be made to a task command to validate the address entered.