Help with Java JNI and C++

Question

Hi everyone! I have a problem with Hello World example. I wrote java code in Visual Age 4.0:
<HelloGinja.java>
package jnitest;
public class HelloGinja {
     static {
          System.load("c://c++//hellotest//release//hellotest.dll");
      * HelloGinja constructor comment.
     public HelloGinja() {
          super();
     public native void displayHelloGinja();
     public static void main (String args[]) {
          System.out.println("Calling displayHelloGinja...\n");
          new HelloGinja().displayHelloGinja();
          System.out.println("Finished displayHelloGinja...\n");
}I made header file from command line:
javah -jni jnitest.HelloGinja
I wrote C++ code in Visual Studio 6.0:
<hellotest.cpp>
#include "stdafx.h"
#include "hellotest.h"
#include <jni.h>
#include "jnitest_HelloGinja.h"
#include <stdio.h>
BOOL APIENTRY DllMain( HANDLE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
    switch (ul_reason_for_call)
          case DLL_PROCESS_ATTACH:
          case DLL_THREAD_ATTACH:
          case DLL_THREAD_DETACH:
          case DLL_PROCESS_DETACH:
               break;
    return TRUE;
// This is an example of an exported variable
HELLOTEST_API int nHellotest=0;
// This is an example of an exported function.
HELLOTEST_API int fnHellotest(void)
     return 42;
// This is the constructor of a class that has been exported.
// see hellotest.h for the class definition
CHellotest::CHellotest()
     return;
extern "C" {
     JNIEXPORT void JNICALL Java_jnitest_HelloGinja_displayHelloGinja(JNIEnv *env, jobject obj)
          printf("\nHello Ginja Glisic!\n");
          return;
}What is the problem? I compile program well but when I run it from VAJ I am getting:
Calling displayHelloGinja...
Finished displayHelloGinja...
It seems like it does not call native method at all. I exported file out from VAJ and run it from command line.I got:
Calling displayHelloGinja...
Hello Ginja Glisic!
Finished displayHelloGinja...
Everything is ok.It works. why then it won't work in VAJ?
Can anyone have idea? I will be very thankfull for any help or advice.

Answer 1

Ok, I solved my problem. I returned string from native method to java code and I got it. The point is native method is being called but I couldn't see it's output from VAJ.
Does anyone know any good tutorial about VAJ? If does, please post it .