How do I declare a native method outside of the main class?

Question

Hi
This is a JNI particular question.
I am having a problem with generating the header .h file after executing javah. The file is generated correctly but is empty under certain circumstances.
This is the 'empty file:
=================
/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class gui_GuiMain */
#ifndef Includedgui_GuiMain
#define Includedgui_GuiMain
#ifdef __cplusplus
extern "C" {
#endif
#ifdef __cplusplus
#endif
#endif
This is what it should look like:
=========================
/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class gui_GuiMain */
#ifndef Includedgui_GuiMain
#define Includedgui_GuiMain
#ifdef __cplusplus
extern "C" {
#endif
* Class: gui_GuiMain
* Method: getValueOIDTestMIB
* Signature: ()V
JNIEXPORT void JNICALL Java_gui_GuiMain_getValueOIDTestMIB
(JNIEnv *, jobject);
#ifdef __cplusplus
#endif
#endif
The header file becomes "empty" when the native function getValueOIDTestMIB is declared in a different class than what my main() function is declared in.
For example something like this will work:
class Main
public native void getValueOIDTestMIB
static {
System.loadLibrary("libsnmp++");
//............some more functions etc.............
public static void main(String[] args)
//............some more stuff...........................
But when I declare this:
public native void getValueOIDTestMIB
static {
System.loadLibrary("libsnmp++");
outside the class, in another class within the same package, nothing happens.
I am probabily doing something stupid. Can somebody help or give me some guidance to where I should look. I come from a C++ background, not a guru in Java.
Thanks

Answer 1

You need to run javah and give it as a parameter the full class name of the class which contains the native methods.
For example (if your class is called A and its package is a.b.c)
javah -jni a.b.c.A