Note: VISampler was written in 2010 and has not been further developed. It can still be used as a useful tool for viewing CT and Voltage waveforms on an Arduino based energy monitor such as the emonTx or self-built monitor.
Installing RXTX Serial library
Download and unzip: rxtx-2.1-7-bins-r2.zip from http://rxtx.qbang.org/wiki/index.php/Download
Copy librxtxSerial.so to java location (this location has changed over the years some web searching may be required in order to find the location on your computer). On Ubuntu 16.04 in 2017 the following worked:
sudo cp rxtx-2.1-7-bins-r2/i686-unknown-linux-gnu/librxtxSerial.so /usr/lib/jvm/default-java/jre/lib/ext sudo cp rxtx-2.1-7-bins-r2/RXTXcomm.jar /usr/lib/jvm/default-java/jre/lib/ext