You can use Unified Modeling Language (UML) class diagrams to create
extends relationships between Java™ classes.
You cannot create extends relationships between Java classes
in the following situations:
- Between two Java classes where the sub Java class already extends another class
(multiple extends or inheritance relationships are not supported in Java)
- Between two Java classes where the super class is a final class
To create an extends relationship between two Java classes:
- In the Palette, click Extends.
- Click the sub (client) Java class, drag it to the super (supplier) Java class,
and release the mouse button.