在资源路径中找不到 JNA 原生支持 (/com/sun/jna/linux-arm/libjnidispatch.so)

Question

I have started to build a java service which incorporates JNA to load a native C/C++ lib and i want to run the java service on the Raspberry PI aka arm platform. I have successfully built a stable ground of the service and it runs on both Windows7 and linux-amd64/debian but.. on the RPI platform i get the above stated error: Exception in thread "main" java.lang.UnsatisfiedLinkError: JNA native support (/com/sun/jna/linux-arm/libjnidispatch.so) not found in resource path

On the RPI i have done the following: * Installed both openjdk7 and java8 beta with arm hard float support. * Installed libjna-java lib.

Following are set:

Java

root@pisces:/opt/TellstickReplay# java -version
java version "1.8.0-ea"
Java(TM) SE Runtime Environment (build 1.8.0-ea-b36e)
Java HotSpot(TM) Client VM (build 25.0-b04, mixed mode)
root@pisces:/opt/TellstickReplay#

LD_LIBRARY_PATH

root@pisces:/opt/TellstickReplay# echo $LD_LIBRARY_PATH
/opt/lib/jna

CLASSPATH

root@pisces:/opt/TellstickReplay# echo $CLASSPATH
/usr/lib/jna

None of the settings seems to satisfy JAVA with JNA support. I have even tried to export both jna.jar and linux-arm.jar into the project in Eclipse and all together rebuild the jars into the exported jar still getting the same error. The exported jar has been tested successfully on both windows and linux so the jar file is working.

I have also tried to just use CLASSPATH in the Manifest in the jar file but with no success. I have also tried to explicitly load the libjnidispatch.so from the absolute path but JAVA then starts to complain that it cannot find the file to libjnidispatch.so even that the path is 100% correct.

So.. does anyone know HOW to correctly get JNA support on the Raspberry PI platform to work?? Please, im getting tremendously frustrated and soon giving up hope to fix this..

Answer 1

Where is libjnidispatch.so on your system? If it's not on your system, JNA will attempt to unpack it from jna.jar from the indicated resource path. If it's not there either, you'll get the UnsatisfiedLinkError .

It's recommended that you explicitly install libjnidispatch.so on your system where possible; the jna.jar bundling is mostly there to facilitate usage on the more common desktop platforms.

linux-arm.jar contains the most recent build of libjnidispatch.so, but only WebStart knows how to automatically load the native from a jar like that. If you unpack it into /opt/lib/jna (or elsewhere on LD_LIBRARY_PATH), you should avoid the link error.

Answer 2

I am re-compiling Apache Spark for RPI2 and I've spent a couple of days to fix the issue. Then I've found the easiest possible solution. All you need to have is a libjnidispatch.so link in your default JVM's native lib path.

sudo -s ln -s /usr/lib/arm-linux-gnueabihf/jni/libjnidispatch.so /usr/lib/jvm/default-java/jre/lib/arm/libjnidispatch.so

Answer 3

I packaged the new jna.jar (4.0) and it includes the linux-arm/libjnidispatch.so. The code I was trying to run now works.

Answer 4

我想说的更多是您使用的操作系统或特定 JRE 系统内部文件夹/包/JNDI 结构中“libjnidispatch.so”位置的“配置故障”，它可能不是布局相同的 Debian 或爪哇JRE。

Answer 5

I do the following:

1. sudo apt-get install libjna-java
2. get the installed jar /usr/share/java/jna.jar
3. Install jna.jar as a maven dependency

They worked to me...