What is the code of Bluetooth chat application

using in Java language

Please describe your problem clearly, with more specific details.

You want to build a Bluetooth chat app using JAVA?

Here is an Android Studio tutorial and link to java source code https://projectgurukul.org/create-android-bluetooth-chat-app/

To build a Bluetooth chat app using App Inventor see Taifun's tutorial App Inventor Tutorials and Examples: Bluetooth Chat | Pura Vida Apps