Real's How-to

JNI requires that the function names follow a specific format. If you have a Java native method in a class called MyClass like this:

public native void myMethod();

the native function must look like this:

JNIEXPORT void JNICALL Java_MyClass_myMethod(JNIEnv *, jobject);

When you put the class into a package (say com.rgagnon), you need to include the package information in the native function name like this:

JNIEXPORT void JNICALL Java_com_rgagnon_MyClass_myMethod(JNIEnv *, jobject);

To generated the proper header, compile the JNI class in the package then, using the javah utility (from the root of the package) :

javah com.rgagnon.MyClass