I'm having this issue with an app I have written for a Scanner running windows mobile 5.0. I have no idea what it means, can anyone with some Java Cre-Me, windows mobile experience lend some assistance please??
Error given on execution:
java.lang.UnsatisfiedLinkError: no SymbolJavaApi in java.library.path
at java.lang.ClassLoader.loadLibraryInternal()
at java.lang.ClassLoader.loadLibrary()
at java.lang.Runtime.loadLibrary0()
at java.lang.System.loadLibrary()
at
at com.vmt.plugins.symbol.barcodescanner.services.ScannerImplementation.read()
at com.vmt.plugins.symbol.barcodescanner.ScannerPlugin.invoke()
at ScannerTest.startScanning()
at ScannerTest.createwindow()
at ScannerTest.main()
For UnsatisfiedLinkError, the JDK states:
Thrown if the Java Virtual Machine cannot find an appropriate
native-language definition of a method declared native.
That means that there is a method inside ScannerImplementation.read() that is a native call definition that it can't in the java.library.path or any system defined libraries.
What this means is that the DLL that is needed for your ScannerImplementation isn't registered in the Java LIB path and thus the JVM can't do a native call.
I hope this helps.
The Java class loader tries to access the Symbol API but can not find the required libraries in the given library path.
On a desktop system I'd say you need:
Either extend the class path accordingly or
Copy missing external DLLs to the path where your application resides
I'm sure that Symbol/Motorola has some examples where you can see how to do that - maybe you need to install the classes to the device first using a CAB file.
I'm coming from a .NET background and for that, there's a Symbol API CAB file which installs required DLLs to the device.
Related
I have java code that needs to use the Vlcj library on a Raspberry Pi 3 B+ with Raspbian. But when starting up with the NativeDiscovery.discover(), i get a "no vlc library found" message. I have tried to use addSearchPath() on "/usr/bin/" with no success.
How can I solve my issue? Thanks
Your JVM needs to know where to find libvlc.so and the VLC plugins.
They are not in "/usr/bin".
There is more than one way to try and resolve this, the simplest perhaps is to use LD_LIBRARY_PATH.
Once you have found the directory containing libvlc.so, you can specify the LD_LIBRARY_PATH environment variable when you start your app.
On my Pi, libvlc.so is in /usr/lib/arm-linux-gnueabihf, so something like (the given jar files in the classpath are just examples):
LD_LIBRARY_PATH=/usr/lib/arm-linux-gnueabihf java -cp vlcj.jar:jna.jar:jna-platform.jar:your-app.jar
This might be enough to make it work, it might not. LibVlc might complain about not being able to find its plugins.
If so, find where the plugins are installed (there should be a directory named "plugins" under the directory where you found libvlc.so).
On my Pi these are in /usr/lib/arm-linux-gnueabihf/vlc/plugins.
Now you set the VLC_PLUGIN_PATH to point to that directory:
LD_LIBRARY_PATH=/usr/lib/arm-linux-gnueabihf VLC_PLUGIN_PATH=/usr/lib/arm-linux-gnueabihf/vlc/plugins java -cp vlcj.jar:jna.jar:jna-platform.jar:your-app.jar
You can set those environment variables in your profile or whatever instead of specifying on the command line if you want.
vlcj's native discovery mechanism generally tries to resolve all of this nastiness for you, but it doesn't (currently) know about Raspberry Pi so you have to do it yourself.
The next major version of vlcj (which will be 4.0.0) has an improved native discovery mechanism. I tested an early development version of this on my Pi and it just worked straight away without any of the above.
In my app, I am adding third party hardware connectivity and using their provided code for java. Also using jna.jar to interact with that code as it uses native library to load some .so files. It throws the error:
java.lang.UnsatisfiedLinkError: Native library (com/sun/jna/android-arm/libjnidispatch.so) not found in resource path (.) Please help where can I get the jar with android-arm/libjnidispatch.so in it.`
I tried adding android-arm.jar which is having libjnidispatch.so separately but compiler is looking for jna.jar's path. Thanks!
Extract the com/sun/jna/linux-arm/libjnidispatch.so from the jar file
put the .so file in the following directory (when using android studio): yourproject\app\src\main\jniLibs\armeabi-v7a\libjnidispatch.so
And also please note that linux architecture != android architecture (google uses a different c library (bionic), which is a different one than the normal linux distributions)
For all architectures see:
https://github.com/java-native-access/jna/tree/master/lib/native
Which version of JNA do you use? (There was a bug in JNA 4.2.2/4.3.0 which might also be a cause)
I am trying to deploy an opencv java application with opencv 2.49, I have build the libopencv_java249.so and opencv-249.jar in the Ubuntu server and these are available in the class path when the application starts.
But it's throwing a exception saying libopencv_java245 not found, so initially I was under a impression that it's referring to a wrong opencv version. so to verify this I have removed the libopencv_java249.so from class path and then it was complaining that libopencv_java249 not available.
As an additional testing I also renamed libopencv_java249.so to libopencv_java245.so then it was saying again that opencv_java249 not found.
With this I guess we can confirm that it looks for the right version of opencv (that is libopencv_java249) but in addition to that it aslo requires libopencv_java245 also. Is my assumption is correct, it would be really helpful if someone can guide me.
I am trying to deploy my application that invokes native calls using JNA library, but I get the following exception.
Exception in thread "main" java.lang.UnsatisfiedLinkError: Unable to load library 'myCustomDLL': Native library (win32-x86-64/myCustomDLL.dll) not found in resource path ([myproject/target/classes/, ...some jars...])
What do I need to do in order to invoke the function correctly?
Any help much appreciated
You must put your dll library (with native code) on application java.library.path.
See :
http://examples.javacodegeeks.com/java-basics/java-library-path-what-is-it-and-how-to-use/
Edit:
Post your project layout here. And how you run your app.
Check whether the DLL is executable.
Check the dependant DLLs are all executable.
With windows explorer, right click on DLL -> property -> security and verify execution rights.
Actually I found the answer to this. Basically, I needed to install Microsoft Visual C++ Redistributable package to install all the necessary DLLs needed for JNA to work. Thanks for other responses to this question.
I am helping to code a stop-motion program that is to be cross platform, and on windows it works great. For those who do not know, stop motion is just a fancy term for animation. This program allows users to plug in Nikons, Canons, and Webcams into the computer, and have the program display a live view of the scene, and then have the ability to manually control the camera from there. Included is a framework file from canon for the camera, with a path defined as shown
import com.sun.jna.Native;
initialization and such
public static EdSdkLibrary EDSDK = (EdSdkLibrary) Native.loadLibrary("Macintosh/EDSDK.framework/EDSDK",EdSdkLibrary.class, options);
The error is thrown at the "public static int..." saying that the image is not found. I have tried numerous times redefining the path, moving the framework, and using various other frameworks identical to the one I'm using. Remember, this works flawlessly on Windows, but on Mac there is a problem.
Are frameworks different on macs, or are they to be defined differently? I have looked and found no other solutions.
EDIT: Okay, I defined the path and it now has this symbol > with no text next to it. WHat do I do now?
EDIT: It is saying that this % is not a command. Without it, it still fails to work.
JNA will successively attempt to load frameworks from ~/Library/Frameworks, /Library/Frameworks, and /System/Library/Frameworks, based on the core framework name (EDSDK in this case).
If the loadLibrary call succeeds, then the library was found. If the library was not found, you'll get an UnsatisfiedLinkError.
Frameworks are basically bundles of a shared library with other resources; ESDK.framework/ESDK is the actual shared library (for frameworks, OSX omits the "dyld" suffix normally found on a shared library on OSX).
EDIT
Here's how to make a symlink so that the paths look more like what JNA is expecting. From a terminal (run Terminal.app):
% ln -s /your/complete/path/to/Macintosh/EDSDK.framework ~/Library/Frameworks/EDSDK.framework
When this is done successfully, you should see the following when listing (ls) the symlink:
% ls -l ~/Library/Frameworks/EDSDK.framework
lrwxrwxr-x 1 YOU YOU 50 Mar 31 01:13 /Users/YOU/Library/Frameworks/EDSDK.framework -> /your/complete/path/to/Macintosh/EDSDK/Framework/EDSDK.framework
You should see the symlink path (where JNA will look) on the left, with the path to the real file on the right. If not, delete the symlink file and try again. Note that you may need to create the directory ~/Library/Frameworks first; it may not yet exist.
Finally, make sure that the library you're trying to load matches the VM you're trying to load with; 64-bit with 64-bit, 32-bit with 32-bit. Canon does not provide a universal binary of their library, so you'll need to point to one or the other or merge the two using lipo.
Not really an answer, but more information on the same problem, which I'm experiencing myself.
I can add that JNA will find my frameworks if they're in one of the standard public locations an executable looks for its frameworks, i.e.
~/Library/Frameworks - (public frameworks for the use of the current user)
/Library/Frameworks - (public frameworks for the use of any user)
/System/Library/Frameworks - (public system frameworks)
However, If I want my custom framework to be private - i.e. - not discoverable to other processes than my java vm -- then for some reason JNA doesn't do it.
I know MacOS dynamic loader, when trying to locate a library/framework for any normal (native) MacOS process, does NOT start searching the above locations, but first within several standard "private" locations: (also known as rpath search-path)
in the "Frameworks" directory at the same location as the binary from which the process was loaded: e.g. path/to/my/binary/Frameworks/mySDK.framework
in the "Frameworks" directory at the place where dynamic loader loaded the process (in Application bundles, that would be the myApp.app/Contents/Frameworks/mySDK.framework folder.
So, you can usually create a 'Frameworks' directory of your own right next to your binary, and place your framework in it.
However - JNA misses that. I tried to create a "Frameworks" directory within the "Zulu" - in zulu-11.jre/Contents/Home/bin right next to the 'java' binary, and in other places - but JNA won't find in any of them.
I wonder why, and if there is any documentation for that.
The trick of installing a symlink to my custom framework in /Library/Frameworks may serve you, but I cannot allow other processes to find or load my framework.