UnsatisfiedLinkError: no opencv_java249 in java.library.path

Look into your OpenCV directory;

For an example this; (installed using brew install opencv3 --with-java --with-python3)

/usr/local/Cellar/opencv3/XXX/share/OpenCV/java

You will see;

libopencv_javaXXX.so    opencv-XXX.jar

Now that you already have OpenCV's native library for Java (libopencv_javaXXX.so) compiled with you, the only thing left is, mac's dynamic library.

Link libopencv_javaXXX.so to libopencv_javaXXX.dylib;

ln -s libopencv_javaXXX.so libopencv_javaXXX.dylib

Now add /usr/local/Cellar/opencv3/XXX/share/OpenCV/java as Native Library Locations in IntelliJ or something similar in Eclipse.

Or add this to your JVM arguments;

-Djava.library.path=/usr/local/Cellar/opencv3/XXX/share/OpenCV/java

On a mac running OSX Yosemite, I dropped the libopencv_java2412.dylib file into /Library/Java/Extensions and it worked.

After you build opencv, the libopencv_java2412.dylib is generated in /build/lib.

After Spending a lots of time , and using different suggestions from StackOverflow I managed to get solution for windows. but I am adding a solution for mac as well. hope it should work.

1. Load your lib as per your system configuration.

   private static void loadLibraries() {
   
       try {
           InputStream in = null;
           File fileOut = null;
           String osName = System.getProperty("os.name");
           String opencvpath = System.getProperty("user.dir");
           if(osName.startsWith("Windows")) {
               int bitness = Integer.parseInt(System.getProperty("sun.arch.data.model"));
               if(bitness == 32) {
                   opencvpath=opencvpath+"\\opencv\\x86\\";
               }
               else if (bitness == 64) { 
                   opencvpath=opencvpath+"\\opencv\\x64\\";
               } else { 
                   opencvpath=opencvpath+"\\opencv\\x86\\"; 
               }           
           } 
           else if(osName.equals("Mac OS X")){
               opencvpath = opencvpath+"Your path to .dylib";
           }
           System.out.println(opencvpath);
           System.load(opencvpath + Core.NATIVE_LIBRARY_NAME + ".dll");
       } catch (Exception e) {
           throw new RuntimeException("Failed to load opencv native library", e);
       }
   }
   

2.now use this method as per your need

public static void main(String[] args) {
    loadLibraries();
}