JNI- java.lang.UnsatisfiedLinkError: Native method not found

Question

I\'m developing an Android project using OpenCV. Some of the methods do not have Java version, so I have to use NDK to use them in my project.

This is my first time

Answer 1

I added

extern "C"

before functions declare ex:

extern "C"
jstring
Java_lara_myapplication_MainActivity_stringFromJNI(
        JNIEnv *env,
    jobject /* this */) {
    std::string hello = "Hello from C++";
    return env->NewStringUTF(hello.c_str());
}

then the error was gone