Java supports communication to serial ports, but not with its default installation. It requires an installation of an external library. Currently, two options exist for achieving serial communication:
Unfortunately, the current version of JavaComm does not support Windows, and only supports Solaris SPARC, Solaris x86, and Linux x86. Since I use none of those operating systems, this article will only discuss how to install RXTX in Windows.
UPDATE: 12 Sept 2011 – Thanks to a comment from Kurt Zoglmann, there are instructions on how to do this with a Mac! I never tried this myself because I don’t have a Mac, but the procedures stated there look good to me (see comments).
A 32 and 64 bit version of the library exists. I’ve updated this article from when it was first published to include the new locations for where to download the libraries, but I have not gone through the installation of the libraries again, so I’m not surprised if the rest of the content on this page is outdated too.
To install the libraries (instructions from JControl):
- Copy rxtxSerial.dll to %JAVA_HOME%\bin, (%JAVA_HOME% is the folder where JRE is installed on your system; e.g. c:\Program Files\Java\j2re1.4.1_01)
- Copy RXTXcomm.jar to %JAVA_HOME%\lib\ext
Once installed, the IDE will need to know where to look for these installed files. Even though the files exist in the JRE directory, each project needs to know about these files. More information on this website.
In order to start coding with this library, import gnu.io.*. For more information about Java Serial Programming, look here.