Tilengine on Java

[System64]

I still update the Java bindings and I have some problems.

I updated some simple functions likes TLN_GetLayerHeight and updated the Tilengine.java too

And when this function is executed, my program crashes and displays :

Exception in thread "main" java.lang.UnsatisfiedLinkError: Tilengine.GetLayerHeight(I)I

at Tilengine.GetLayerHeight(Native Method)
at TestWindow.main(TestWindow.java:46)

Is it normal? the method in Java is public native int GetLayerHeight (int nlayer); and the function in the binding is 

JNIEXPORT jint JNICALL Java_Tilengine_GetLayerHeight (JNIEnv* env, jobject thisobj, jint nlayer)
{
    return TLN_GetLayerHeight (nlayer);
}

Is it normal? Also, I just did a commit on my github fork so it's possible to see the changes I did.
Thanks for the answer