Call Java methods with DataWeave

April 16, 2020

As Mule is being built on top of Java and Spring, there’s a strong integration capability in Mule to invoke Java methods. There are numerous ways to invoke a Java method in Mule.

From a DataWeave statement, you can call Java methods from any Java class that’s in your Mule project.

In this blog, we’ll learn an approach by using Java Component to call custom Java class:

Invokes a static method on a provided instance
Instantiate Java class
Invoke a non static method

Invoke a Java static method from a class

Step 1: Create a class as part of a Java package named “utils” in your Mule project’s src/main/java folder.

Step 2: Create a Mule flow to call the method appendRandom() from Dataweave code.

Step 3: Dataweave script to call appendRandom().

Step 4: Postman Console

Instantiate Java class

Step 1: Create a class as part of a Java package named “utils” in your Mule project’s src/main/java folder.

Step 2: Create a Mule flow to call the method appendRandom() from Dataweave code.

Step 3: Dataweave script to call appendRandom().

Step 4: Postman Console

Invoke a Java non static method from a class

Step 1: Create a class as part of a Java package named “utils” in your Mule project’s src/main/java folder.

Step 2: Create a Mule flow to call a non-static function. We need to first create an instance of the class by using the “New” and “Invoke” Java component from the Mule palette.