Mule has the concept of components which are used to execute custom business logic within flows. It has excellent in-built support to define components and also has a different kinds of components that a developer can choose from. There is good documentation on the Mulesoft portal about how to use each of these types of components but I could not find guidance on choosing the right kind of component for a given use case. This post focuses what the Mule documentation calls Script components.
The post is about the guidelines I use to decide which kind of component to use in a given situation.
Mule Script components come in two broad categories.
- Scripting language based
- Java language based components
|Scripting language based components||Java language based components|
|They are concise to write because they can be directly embedded into the flow XMLs.
||They are more verbose as there is a need to create class and method.|
|They are harder to unit test as they cannot be tested using JUnit tests and writing MUnit tests is more verbose and complicated compared to JUnit tests.||They are easier to test as they can unit tested using simple JUnit tests.|
|You cannot use step through debugging.||
You can use step through debugging.
I use scripting language components for small snippets of code and use Java-based components for larger pieces of business logic. I often find myself starting with a scripting language component and then later refactoring it into a Java-based component.
Within Java-based components we have three ways of defining a Java-based component
- Mule component
- Spring component with annotation
- Java invoke component
In the next post I will discuss the pros and cons for each of these Java component types.