java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path

Here's how to fix the error 'java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path' when running a Java application on the Raspberry Pi.

Install librxtx using the following command:

sudo apt-get install librxtx-java

Copy the rxtx files from the following directory:

/usr/lib/jni

and put them into this directory:

/usr/lib

Now try and run your Java application and it should work fine. :D