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
Oracle/Sun dropped support for the original JavaComm API years ago, making it hard to find official downloads. While it was once a stable and flexible
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). Overview & Purpose Oracle/Sun dropped support for the
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)