WID tips: limit amount of Java code in snippets

When you need to add custom functionality to an application you develop in WebSphere Integration Developer or extend its capabilities, you use Java. There are several ways to do this and at least one is available in each context:

  • on the module/assembly diagram level – create a Java component
  • inside a mediation flow – write your Java in a Custom Mediation primitive
  • in a BPEL process – use Snippet activity
  • in a BO map – use Custom transform

Best practice: only trivial code should go into Snippets and Custom Transform. Refactor more complex code into a utility Java class.

To promote code clarity and simplify maintenance, troubleshooting and debugging, I strongly urge limiting the amount of code you put in Custom Primitive, Snippet and Custom Transform to. Only trivial code should go there. Please do not implement complex or business-relevant logic there. These Java usages are not easily accessible (hidden behind layers of components), difficult to code-review and more cumbersome to step through when using a debugger. If you need to execute something more complex, refactor the logic into a separate utility class and limit your snippet (or custom transform) to a simple method call on the utility class. This approach adheres to many architectural best practices: separation of concerns (Information Expert pattern), promotion of reusability. Code quality improves and your application is easier to understand and maintain.