Actions are the basic building blocks of ESB services. In the previous chapter, we discussed ESB services and their behavior, how to combine services, and touched on the use of actions within a service. In this chapter we'll go into a deeper discussion of actions, how and when to write your own action, and what actions are provided to you within JBoss ESB.
You'll learn about:
- What actions are and how you can combine actions into an "action chain" to have your services perform complex, multi-step tasks.
- How you can make use of JBoss ESB's extensive set of out-of-the-box (OOTB) actions to perform tasks without your having to write custom code.
- And finally, how you can write custom actions to perform tasks that are not already supported by OOTB actions.
For JBoss ESB services, actions are literally where the action is. Sorry, pardon the pun, please!
But, seriously, actions are the means by which services perform their tasks. Actions are how you route messages between services, convert (or "transform") data from one form to another, execute scripts or exercise integrations between JBoss ESB and other packages.
There are two types of actions:
- Out-of-the-box actions: A wide array of out-of-the-box (OOTB) actions ship with JBoss ESB. When you are designing your services, the place to start is the out-of-the-box actions. These have all been tested with JBoss ESB and they've also been documented and used as examples by the quickstarts.
- Custom actions: These are actions that you design and build yourself. We'll discuss both types of actions, how you use them, and, for custom actions, how you build them, in this chapter.
