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

Question

I am trying to use the 64 bit rxtx serial communication library (downloaded from cloudhopper) with 64bit windows 7 and eclipse. I get the message: java.lang.Unsatisfi

Answer 1

Under Netbeans 5.5 on Windows, I needed to right-click Libraries under Projects on the left hand side of the screen, and select "Add JAR/Folder", picking the RXTXcomm.jar file. Only then did my

enter code here

become a valid command. Also, I got a run-time error where it failed to load the rxtxSerial.DLL library because it couldn't find it. I needed to right-click the project name, select properties, select Run under categories, and add a VM Options: entry of

-Djava.library.path="C:\where-ever-you-stuck-rxtxSerial.DLL-file;%PATH%

Example:

-Djava.library.path="C:\rxtx-2.1-7-bins-r2\Windows\i368-mingw32\;%PATH%"

While I'm sure there is more than one way of adding the directory to your path, this worked for me. Note I did the default NetBeans 5.5/JDK 1.6.0 isntall accepting all the default options(ie clicking next until I got to finish), so I haven't modified my java paths or anything. Alternatively you can copy the *.dll into C:\Windows\System32\, Java will find it there automatically.

Note that you cannot use the 32bit DLL when running a 64bit JRE: You will get an error similar to:

Can't load IA 32-bit .dll on a AMD 64-bit platform thrown while loading gnu.io.RXTXCommDriver

To solve this simply install the 32bit JDK and add a new Platform in Netbeans under Tools->Java Platforms->Add Platform and change the project settings to use the newly created platform. make sure you type

"import gnu.io.*"

from http://rxtx.qbang.org/wiki/index.php/Using_RXTX_In_NetBeans