如何编译opencv java,如何在jar中打包opencv + java

I've been using Opencv 2.4.5 with Java for a while building an application and would now like to distribute the app. The library is loaded using the following:

static{

System.loadLibrary("opencv_java245");

}

which works fine. However, when exporting, it doesn't work when running from the jar:

java -jar build1.jar

The opencv_java245.jar file is included as a user library, with a native file (libopencv_java245.dylib) connected to it. When running the executable jar generated from Eclipse, I get the UnsatisfiedLinkError below, despite things compiling/running fine in eclipse.

Exception in thread "main" java.lang.UnsatisfiedLinkError: no opencv_java245 in java.library.path

at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1860)

at java.lang.Runtime.loadLibrary0(Runtime.java:845)

at java.lang.System.loadLibrary(System.java:1084)

at com.drawbridge.Main.(Main.java:12)

at java.lang.Class.forName0(Native Method)

at java.lang.Class.forName(Class.java:266)

at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:56)

Anyone know a simple way of packaging OpenCV in the jar?

Update: I have now exhausted everything. I can add the library to my build path (and not use System.loadLibrary) and that works in eclipse, but not when packaged in the jar. I've tried everything. I also checked the type of dynamic library I'm trying to load - it's

Mach-O 64-bit x86_64 dynamically linked shared library

which seems like it should work fine. I've used -D64 and -D32 to test and get the same result with both.

解决方案

As Steven C said, it was as in Extract and load DLL from JAR and also in a bug report. I was slightly ignorant of how to use dylibs and was trying to be consistent with an OpenCV tutorial which used a "user library" to add a jar, and then add the native dylib. Also, for some reason loading resources even when using "/" was loading from the src directory, not my project's root directory (which was the case in a test project I made).

For those trying to do the same thing, here's some code to help:

private static void loadLibrary() {

try {

InputStream in = null;

File fileOut = null;

String osName = System.getProperty("os.name");

Utils.out.println(Main.class, osName);

if(osName.startsWith("Windows")){

int bitness = Integer.parseInt(System.getProperty("sun.arch.data.model"));

if(bitness == 32){

Utils.out.println(Main.class, "32 bit detected");

in = Main.class.getResourceAsStream("/opencv/x86/opencv_java245.dll");

fileOut = File.createTempFile("lib", ".dll");

}

else if (bitness == 64){

Utils.out.println(Main.class, "64 bit detected");

in = Main.class.getResourceAsStream("/opencv/x64/opencv_java245.dll");

fileOut = File.createTempFile("lib", ".dll");

}

else{

Utils.out.println(Main.class, "Unknown bit detected - trying with 32 bit");

in = Main.class.getResourceAsStream("/opencv/x86/opencv_java245.dll");

fileOut = File.createTempFile("lib", ".dll");

}

}

else if(osName.equals("Mac OS X")){

in = Main.class.getResourceAsStream("/opencv/mac/libopencv_java245.dylib");

fileOut = File.createTempFile("lib", ".dylib");

}

OutputStream out = FileUtils.openOutputStream(fileOut);

IOUtils.copy(in, out);

in.close();

out.close();

System.load(fileOut.toString());

} catch (Exception e) {

throw new RuntimeException("Failed to load opencv native library", e);

}