Develop Reference

How to remove this Exception "Exception in thread "main" java.lang.UnsatisfiedLinkError: no jniopencv_objdetect in java.library.path"

I'm working on Face Recognition Project by using OpenCV 2.4.9, JavaCV 0.7,JAVA version 8 and Eclipse IDE... I am getting these Exceptions continuously.. Is there something wrong in the follwoing code? It's not my complette code...
Please Someone help me as soon as possible...
import com.googlecode.javacpp.Loader;
import com.googlecode.javacv.cpp.opencv_objdetect;
Loader.load(opencv_objdetect.class);
Exceptions:
Exception in thread "main" java.lang.UnsatisfiedLinkError: no jniopencv_objdetect in java.library.path
at java.lang.ClassLoader.loadLibrary(Unknown Source)
at java.lang.Runtime.loadLibrary0(Unknown Source)
at java.lang.System.loadLibrary(Unknown Source)
at com.googlecode.javacpp.Loader.loadLibrary(Loader.java:711)
at com.googlecode.javacpp.Loader.load(Loader.java:586)
at com.googlecode.javacpp.Loader.load(Loader.java:540)
at com.googlecode.javacv.cpp.opencv_objdetect.<clinit>(opencv_objdetect.java:91)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.googlecode.javacpp.Loader.load(Loader.java:561)
at FaceRecognizer.<init>(FaceRecognizer.java:56)
at FaceRecognizer.main(FaceRecognizer.java:112)
Caused by: java.lang.UnsatisfiedLinkError: C:\Users\XYX\AppData\Local\Temp\javacpp183187286948746\jniopencv_objdetect.dll: Can't find dependent libraries
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary0(Unknown Source)
at java.lang.ClassLoader.loadLibrary(Unknown Source)
at java.lang.Runtime.load0(Unknown Source)
at java.lang.System.load(Unknown Source)
at com.googlecode.javacpp.Loader.loadLibrary(Loader.java:700)
... 8 more

This page gives a description of how to get an OpenCV Java sample running. There should be two things that you need to do:
You need to call System.LoadLibrary specifying the OpenCV DLLs that it uses
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
Make sure the DLL in somewhere where it can be found by the JVM. There are a few ways if doing that. I don't use Eclipse but this seems to give a good explanation. Alternatively, a simple bodge just to get things working is to drop the DLL into the windows\system32 directory
Finally there may be an issue if you are running a 64 bit JVM but trying to use a 32 bit DLL. If you are still having trouble make sure you are using matching JVM and DLL.

It looks like one of the java libraries that you are using in your project is using jni calls that uses dll files. Do you have the library installed correctly? It looks like it is called opencv or something that is related to jniopencv_objdetect.dll

Lauch Eclipse SWT window application from command line error

First off. I am a newbie and green with respect to Java programming.
I created a Java Eclipse "SWT" "Application Window" on a Eclipse Kepler 4.3.1 (32-bit) running WindowBuilder and SWT (swt.jar). The design view is a composite.
The java application runs fine from Eclipse. I simply press the play button and presto.
Problem:
Issuing
java -cp . PkgNetAccelerator32.netAcceleratorApp
yields the following error message:
Exception in thread "main" java.lang.NoClassDefFoundError: org/eclipse/swt/widgets/Composite
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
at java.lang.Class.getMethod0(Unknown Source)
at java.lang.Class.getMethod(Unknown Source)
at sun.launcher.LauncherHelper.getMainMethod(Unknown Source)
at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)
Caused by: java.lang.ClassNotFoundException: org.eclipse.swt.widgets.Composite
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 6 more
I was doing some research and several posts on other issues suggested that the cure is to create a manifest. I saw an article that said something like:
Select the src folder, right click and select export, then Java, then JAR file, specify Manifest.jar and a path on the folder, make sure the "Generate the manifest file" is selected, and press finish.
I created the manifest file and tried launching it with the following command line:
java -jar ../Manifest.jar -cp . PkgNetAccelerator32.netAcceleratorApp
That yielded the same error message above.
I saw another article that said that one should add in the swt.jar file, but that is taken care of by the manifest. No? Specifying "swt.jar" instead of the manifest that I created resulted in an error message:
no main manifest attribute, in ../swt.jar
That error message makes sense.
I am at a loss. How do I run the java application?
I am testing on my Windows 7 Professional 64-bit desktop, but I need to run on CENTOS too. That should be no problem, as I assume whatever the fix on Windows is, will work on CENTOS.
UPDATE:
I placed the two lib files in a /lib folder to match the answer given. I then issued the following command line and got the following error message.
C:\SoftDev\Projects\NetAccelerator\JavaWorkspace\NetAccelerator32>java -cp "bin/*;lib/*" PkgNetAccelerator32.netAcceleratorApp
Exception in thread "main" java.lang.UnsatisfiedLinkError: Cannot load 32-bit SWT libraries on 64-bit JVM
at org.eclipse.swt.internal.Library.loadLibrary(Unknown Source)
at org.eclipse.swt.internal.Library.loadLibrary(Unknown Source)
at org.eclipse.swt.internal.C.<clinit>(Unknown Source)
at org.eclipse.swt.widgets.Display.<clinit>(Unknown Source)
at PkgNetAccelerator32.netAcceleratorApp.open(netAcceleratorApp.java:43)
at PkgNetAccelerator32.netAcceleratorApp.main(netAcceleratorApp.java:33)
I found the following article, which produces a command line that works, just that is not reasonable for sending. I much rather use the answer.

Lets assume you have a eclipse project structure similar to this:
Workspace
-> Project
-> src (source code directory)
-> bin (compiled byte code directory as JAR)
-> lib (jar directory)
-> .classpath (eclipse file)
-> .project (eclipse file)
I am assuming that you are exporting the JAR as an executable JAR.
So in order to run a class in that exported JAR with another JAR from the lib directory (swt.jar) while your working directory is the Project directory you will need to execute:
java -cp "bin/*:lib/*" PkgNetAccelerator32.netAcceleratorApp
Using wildcards requires Java 6 or later
Please note: CENTOS requires : as a path separator. Windows uses a semi-colon.
This will add your classes and the swt classes onto the classpath and run your main class PkgNetAccelerator32.netAcceleratorApp
SWT 32bit vs 64bit
You will either need to use a 32bit JVM locally or continue to use a 64bit JVM and use the 64bit version of swt; see swt on windows 64 bit. I would suggest you match your version of your local JVM (32bit or 64bit) with the version that you will be running on the CENTOS machine. You will however need a different swt jar for CENTOS.

SWT: Running an application developed on OSX in Windows

I have an SWT application that I've developed on OSX, so it contains the Mac version of the SWT libraries.
Now I need to run this application on a Windows machine. I export the application to a .jar file, but when I attempt to execute the jar in Windows, I get:
Exception in thread "main" java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoa
der.java:58)
Caused by: java.lang.UnsatisfiedLinkError: Could not load SWT library. Reasons:
no swt-cocoa-4236 in java.library.path
no swt-cocoa in java.library.path
Can't load library: \\psf\Home\.swt\lib\win32\x86\swt-cocoa-4236.dll
Can't load library: \\psf\Home\.swt\lib\win32\x86\swt-cocoa.dll
at org.eclipse.swt.internal.Library.loadLibrary(Unknown Source)
at org.eclipse.swt.internal.Library.loadLibrary(Unknown Source)
at org.eclipse.swt.internal.C.<clinit>(Unknown Source)
at org.eclipse.swt.widgets.Display.<clinit>(Unknown Source)
at display.StoragePickupDisplay.open(StoragePickupDisplay.java:70)
at display.StoragePickupDisplay.main(StoragePickupDisplay.java:58)
... 5 more
I have added the Windows version of SWT libraries but that didn't make a difference. I need the Mac libraries to be in there for continued development. How can I get around this?

You have to add the correct SWT.jar to the classpath. You can download them here.
If you are deploying for Windows, you will have to bundle the swt jar for Windows (either 32bit or 64bit depending on the system).
If you want to create an application that runs on all platforms, have a look at this post:
Create cross platform Java SWT Application

Trying to make java application (Executable Jar) that uses OpenCV portable. Getting unsatisfied link error

I have made a application to grab video from a webcam and detect motion using OpenCV and JavaCV. I am trying to export as an executable jar using eclipse. The program runs fine in eclipse as does the exe jar on the computer I coded the program on.
What I am trying to accomplish is to make the exe Jar run on computers that don't have OpenCV installed. Basically what I would consider a portable application. When I run the exe jar on a different computer that has nothing installed other than the JRE I get unsatisfied link errors seen below.
Exception in thread "Video Thread" java.lang.UnsatisfiedLinkError: C:\Users\JohnD\AppData\Local\Temp\javacpp91062429652918\jniopencv_core.dll: Can't find dependent libraries
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary1(Unknown Source)
at java.lang.ClassLoader.loadLibrary0(Unknown Source)
at java.lang.ClassLoader.loadLibrary(Unknown Source)
at java.lang.Runtime.load0(Unknown Source)
at java.lang.System.load(Unknown Source)
at com.googlecode.javacpp.Loader.loadLibrary(Loader.java:566)
at com.googlecode.javacpp.Loader.load(Loader.java:489)
at com.googlecode.javacpp.Loader.load(Loader.java:431)
at com.googlecode.javacv.cpp.opencv_core.<clinit>(opencv_core.java:136)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.googlecode.javacpp.Loader.load(Loader.java:453)
at com.googlecode.javacv.cpp.opencv_imgproc.<clinit>(opencv_imgproc.java:97)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.googlecode.javacpp.Loader.load(Loader.java:453)
at com.googlecode.javacv.cpp.opencv_highgui.<clinit>(opencv_highgui.java:85)
at com.googlecode.javacv.OpenCVFrameGrabber.start(OpenCVFrameGrabber.java:174)
at VideoPanel.run(VideoPanel.java:163)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.UnsatisfiedLinkError: no opencv_core244 in java.library.path
at java.lang.ClassLoader.loadLibrary(Unknown Source)
at java.lang.Runtime.loadLibrary0(Unknown Source)
at java.lang.System.loadLibrary(Unknown Source)
at com.googlecode.javacpp.Loader.loadLibrary(Loader.java:593)
at com.googlecode.javacpp.Loader.load(Loader.java:481)
... 13 more
I have looked for a solution to what I am doing wrong. Most of the topics I have come across with unsatisfied link errors like the ones I am receiving have been trying to get it to run the first time through within there IDE, which is not the case here. I would think my dependencies are correct in the libraries in the build path since I can get it to run perfectly when I am on the computer that has everything installed but I still believe I am doing something wrong with the build.
Again I am trying to make it so the Jar can run on computers where OpenCV/JavaCV is not installed. Any help would be greatly appreciated.

If opencv is not installed in the target machine, than you need to deliver the necessary opencv's dll file and set the corresponding library path, opencv is a precondition of javacv
for example:
jar yourapp.jar -Djava.library.path="/path/to/OpenCV/library"
also check this answer

NoClassDefFoundError org/eclipse/swt/SWTError

I m trying to compile an open source software . The build works fine and results into a jar file "five-server.jar". When I try to run this file from cmd , I get these errors.
C:\Users\vickey\code\five-server\dist\main>java -jar five-server.jar
Exception in thread "main" java.lang.NoClassDefFoundError: org/eclipse/swt/SWTError
Caused by: java.lang.ClassNotFoundException: org.eclipse.swt.SWTError
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: org.devtcg.five.Main. Program will exit.
any suggestion what is wrong?

The SWT Jar files are platform dependent.
See http://www.jarfinder.com/index.php/java/info/org.eclipse.swt.SWTError
e.g. on Windows a suitable jar would be:
org.eclipse.swt.win32.win32.x86_3.1.0.jar
or on Mac OS X:
swt-macosx-3.0m7.jar
and so on.
You might run into call kinds of followup problems if you add this dependency e.g. whether you are
using 32bit or 64bit libraries.
It is too bad that these kind of dependency problems show up more often than not these days :-(

You have to set the classpath so that it includes at least the class org.eclipse.swt.SWTError
or the jar containing it:
java -classpath path/to/jar/containing/org.eclipse.swt.SWTError -jar five-server.jar
You should also set the Main-class attribute in the manifest file in the five-server.jar

Following the #Wolfgang Fahl answer, you might download the references here:
Standard Widget Toolkit » 4.3 x86
Maven reference:
https://mvnrepository.com/artifact/org.eclipse.swt.org.eclipse.swt.win32.win32.x86.4.3.swt/org.eclipse.swt.win32.win32.x86/4.3
Jar file:
http://central.maven.org/maven2/org/eclipse/swt/org/eclipse/swt/win32/win32/x86_64/4/3/swt/org.eclipse.swt.win32.win32.x86_64/4.3/org.eclipse.swt.win32.win32.x86_64-4.3.jar
Standard Widget Toolkit » 4.3 x64
Maven reference: https://mvnrepository.com/artifact/org.eclipse.swt.org.eclipse.swt.win32.win32.x86_64.4.3.swt/org.eclipse.swt.win32.win32.x86_64/4.3
Jar file:
http://central.maven.org/maven2/org/eclipse/swt/org/eclipse/swt/win32/win32/x86_64/4/3/swt/org.eclipse.swt.win32.win32.x86_64/4.3/org.eclipse.swt.win32.win32.x86_64-4.3.jar