CommPortIdentifier (discovers and names ports like /dev/ttya or COM1 ) and CommPort (abstracts the port and manages InputStream / OutputStream ).
It is not part of the standard JDK, requiring manual installation of comm.jar and platform-specific native libraries ( .dll or .so files).
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
The package, often referred to as the Java Communications API or JavaComm, is a legacy API developed by Sun Microsystems to provide Java applications with low-level, asynchronous access to serial ( ) and parallel ports. Overview & Purpose If you are working on a legacy system,
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.
Uses a Java event model to detect changes in signal lines (e.g., carrier detect). Review & Status (As of 2026) Uses a Java event model to detect changes in signal lines (e
(like jSerialComm) if you are starting a new project. What is your current goal with javax.comm ? Opening up new ports to Java with javax.comm - InfoWorld