capture samples should look like alBufferData:
static void JNICALL Java_org_lwjgl_openal_AL10_nalBufferData(JNIEnv *env, jclass clazz, jint buffer, jint format, jobject data, jint data_position, jint size, jint freq) {
ALvoid *data_address = ((ALvoid *)(((char *)(*env)->GetDirectBufferAddress(env, data)) + data_position));
alBufferData(buffer, format, data_address, size, freq);
}