While it was once a stable and flexible solution for Java-to-hardware communication, javax.comm should be avoided for new projects . It is extremely difficult to set up on modern systems, and superior, actively maintained libraries are readily available.
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 Package Javax Comm
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. While it was once a stable and flexible