http://www.bluecove.org/
BlueCove: A popular open-source library that provides Java APIs for Bluetooth communication. It supports multiple Bluetooth profiles and offers platform independence.
https://github.com/intel-iot-devkit/tinyb
TinyB: A lightweight and efficient library for Bluetooth Low Energy (BLE) communication. It allows you to discover and interact with BLE devices, read/write characteristics, and handle notifications.
https://github.com/dariuszseweryn/RxAndroidBle
RxAndroidBle: A reactive Bluetooth Low Energy library for Android, based on RxJava. It simplifies working with BLE devices by providing convenient APIs for scanning, connecting, and interacting with characteristics.
https://github.com/sputnikdev/bluetooth-manager
The Bluetooth Manager is a Java library that provides a high-level and user-friendly API for Bluetooth communication. It offers a range of features for discovering nearby Bluetooth devices, connecting to them, and exchanging data. The library also supports both classic Bluetooth and Bluetooth Low Energy (BLE) devices, making it suitable for a wide range of applications. With its intuitive interface and comprehensive functionality, the Bluetooth Manager library simplifies the process of working with Bluetooth devices in Java applications.
https://github.com/hypfvieh/bluez-dbus
Bluez-DBus: A Java library that wraps the BlueZ D-Bus API, allowing you to interact with Bluetooth devices on Linux systems. It provides comprehensive access to Bluetooth functionality, including device management, pairing, and service discovery.