It can be notoriously difficult to configure, often requiring precise placement of javax.comm.properties . It has known limitations with 64-bit Windows and is not truly cross-platform without bundling separate native libraries for each target system.
Oracle/Sun dropped support for the original JavaComm API years ago, making it hard to find official downloads. Package Javax Comm
If you are working on a legacy system, I can provide tips on: Finding the libraries Troubleshooting the "No serial ports found" error It can be notoriously difficult to configure, often
The de facto standard replacement for many years was RXTX (e.g., org.rxtx:rxtxcomm ), but it is also considered old. Modern Java serial communication is typically handled via modern, maintained libraries like jSerialComm or jSSC (Java Simple Serial Connector). Package Javax Comm