Yes, you may but please read the Note first.
Note
Technical support is not provided if you are using Astah on
unsupported requirements.
If alert below appears, add
-nojvchk option at launch.

Windows
- Have your preferred JDK installed on your PC
- Rename the "jre" folder in the Astah install folder to something else
- Astah detects the latest Java (Should be the Java you installed at step 1) in your PC and then automatically uses it to run
Mac
- Copy a "jre" folder in the JDK installation folder you prefer to use
- Right-click Astah App and select [Show Package Contents] from its pop-up menu

- Pasete the "jre" folder under Contents/Plugins/JDK/Contents/Home.

Linux
Please refer to
How to run Astah on Linux.