I'm trying to compile a java-program written with OpenCV 3.2.0 from the terminal. It was originally written in Eclipse with OpenCV as a user library. I compile it with this command:
javac -cp /opencv-3.2.0-java/build/bin/ *.java
It works with no error, the -cp command shows the path to the OpenCV jar. I then try to run everything with this command:
java -Djava.library.path="/opencv-3.2.0-java/build/lib" -cp jar/opencv-320.jar -classpath . Main
It gives me this error:
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: org/opencv/core/Mat
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
at java.lang.Class.getMethod0(Class.java:3018)
at java.lang.Class.getMethod(Class.java:1784)
at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: org.opencv.core.Mat
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
I searched for solutions to this problem and came to the conclusion that it had something to do with native libraries. I use the -Djava
parameter to link to the path of the library files from OpenCV, but it still doesn't work somehow. How do I fix this?
EDIT:
All the .java files are on a folder on the desktop. This is were the Main file is included. For example:
home/pi/Desktop/MultiSensor_v2.0_Java/Main.java
The path to the OpenCV jar:
/home/pi/Desktop/MultiSensor_v2.0_Java/opencv-3.2.0-java/build/bin/opencv-320.jar
The path to OpenCV native libraries:
/home/pi/Desktop/MultiSensor_v2.0_Java/opencv-3.2.0-java/build/lib
-cp
is short for -classpath
. So I suspect that when you use both, the second one overwrites the first.
You can have multiple entries on the class path separated by :
as stated in the documentation: Setting the class path . (actually, it looks like that is a typo in the doc, and it should be ;
as a separator. You could try both)
If you execute your command from the directory home/pi/Desktop/MultiSensor_v2.0_Java/
that would make:
java -Djava.library.path="opencv-3.2.0-java/build/lib" -cp .:opencv-3.2.0-java/build/bin/opencv-320.jarr Main
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.