I have a file called RXTXcomm.jar that needs to be added to the classpath. This file references another file - rxtxSerial.dll - that also needs to be added to the classpath.
The Classpath variable consists of a list of directories and JAR files containing your CLASS files. Only the CLASS files will be searched using this list. You cannot add a file to this list. In which of those directories do you intend to install the DLL file?
The location of library files is usually specified using the Library Path parameter. The Library Path parameter similarly specifies the folders containing library files (the DLLs).