CelerCOM is a free minimalistic Java library, which can be used to interact with external devices over COM ports, for example: USB, virtual COM. The library has no external dependencies. Native drivers are included for 32-bit and 64-bit Windows and Linux. A pure Java driver is available as a fallback for other OS and architectures.
The library is available for free: https://www.celersms.com/CelerCOM.htm
The TTY example shows how to read and write text commands (i.e. AT commands) through the console.