java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path thrown while loading gnu.io.RXTXCommDriver

Question

Fedora using right now (package is installed Package rxtx-2.2-0.5.20100211.fc15.i686 already installed and latest version ).

I have used/tried:

# locate librxtxSerial
/home/sun/Downloads/rxtx-2.1-7-bins-r2/Linux/i686-unknown-linux-gnu/librxtxSerial.so
/home/sun/Downloads/rxtx-2.1-7-bins-r2/Linux/ia64-unkown-linux-gnu/librxtxSerial.so
/home/sun/Downloads/rxtx-2.1-7-bins-r2/Linux/x86_64-unknown-linux-gnu/librxtxSerial.so
/home/sun/Downloads/rxtx-2.1-7-bins-r2/Mac_OS_X/librxtxSerial.jnilib
/home/sun/Downloads/rxtx-2.1-7-bins-r2/Solaris/sparc-solaris/sparc32-sun-solaris2.8/librxtxSerial-2.1-7.so
/home/sun/Downloads/rxtx-2.1-7-bins-r2/Solaris/sparc-solaris/sparc32-sun-solaris2.8/librxtxSerial.so
/home/sun/Downloads/rxtx-2.1-7-bins-r2/Solaris/sparc-solaris/sparc64-sun-solaris2.8/librxtxSerial-2.1-7.so
/home/sun/Downloads/rxtx-2.1-7-bins-r2/Solaris/sparc-solaris/sparc64-sun-solaris2.8/librxtxSerial.so
/usr/lib/rxtx/librxtxSerial-2.2pre1.so
/usr/lib/rxtx/librxtxSerial.so

Then used:

-Djava.library.path=/usr/lib/rxtx/librxtxSerial.so -Djava.library.path=/usr/lib/jni

But still i get always this following:

java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path thrown while loading gnu.io.RXTXCommDriver
Exception in thread "main" java.lang.UnsatisfiedLinkError: no rxtxSerial in java.library.path
    at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1681)
    at java.lang.Runtime.loadLibrary0(Runtime.java:840)
    at java.lang.System.loadLibrary(System.java:1047)
    at gnu.io.CommPortIdentifier.<clinit>(CommPortIdentifier.java:83)
    at main.Tty.sendCommand1(Tty.java:212)
    at main.Tty.main(Tty.java:236)

How to resolve this ?

Follow up:

WRONG:

-Djava.library.path=/usr/lib/rxtx -Djava.library.path=/usr/lib/jni

CORRECT

-Djava.library.path=/usr/lib/jni -Djava.library.path=/usr/lib/rxtx

Solution 1

I guess the problem is that you have multiple -Djava.library.path parameters and the second one is overwriting the value of the first. The value should also be the path to the folder containing the library, not including the library name.

On linux system you should be able to combine both path parameters using a colon as separator:

-Djava.library.path=/usr/lib/rxtx:/usr/lib/jni

Solution 2

Had same problem with v4l4j library installed from repositories. In ununtu netbeans project failed to start from IDE, but worked fine as jar.

Solved by putting *.so files to /usr/lib not /usr/lib/jni folder.

Solution 3

Project -> properties -> Java build path ->Find your .jar. Click on + to open the JAR's properties. Select Native library location and edit it to point to RXTX's shared library (.DLL, .so, .dylib).