Java, JNI, C++ and a Delphi dll

I asked this question to the Java Folks but I think that the answer will probably come from here. If you answer well here then you can get the 250 points from the java group also.

I have a dll that was originally written in Delphi. The Delphi dll is designed to interface with a (windows) program that is already running. I wrote a C++ wrapper for the Delphi dll so I could use JNI to interface between my application and the windows one.

Everything seems to work when I have a console application. When I interface with the dll from a JFrame it also works, right up until I terminate the application (using System.exit(0) or the defaultClose Operation on a JFrame). Then I get the following error messages:

First Window Title - "java.exe - Application Error"
Message - "The exception unknown software exception (0x0eedfade) occured in the application at location 0x77e6d756"

Second Window Title "Error"
Message - "Runtime Error 217 at 0F05B976"

The java code is shown below. Note that if I just comment out "frame.setVisable(true)" I no longer get the error.

package oziphoto.nat;

import javax.swing.*;

public class OZIJava{
 
 static {
   System.loadLibrary("ozijava");
 }
 

 
 public native int joziLoadWPFile(String filename);
   
 public native int joziFindOZI();
 
 public static void main(String[] args){
     OZIJava test = new OZIJava();
     if(test.joziFindOZI()==0){
         test.joziLoadWPFile("D:\\Documents and Settings\\alistair\\Desktop\\out.wpt");
     }
     JFrame frame = new JFrame();                    
     frame.setVisible(true);
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}



The c++ code is:

#include <jni.h>
#include "OZIJava.h"

HINSTANCE oziApiDll;  

ToziLoadWPfile oziLoadWPfile;
ToziFindOzi oziFindOzi;


JNIEXPORT jint JNICALL Java_oziphoto_nat_OZIJava_joziLoadWPFile
 (JNIEnv * env, jobject jobj, jstring name) {
   LoadOziApiDll();
 
   
   int return2;
   
   const char *str;

   str = env->GetStringUTFChars(name, 0);

    LPSTR FileName = (LPSTR)malloc(50);
   strcpy(FileName, str);
   return2 = oziLoadWPfile(&FileName);
   free(FileName);
   
   env->ReleaseStringUTFChars(name, str);
   

   return return2;
}

JNIEXPORT jint JNICALL Java_oziphoto_nat_OZIJava_joziFindOZI
(JNIEnv * env, jobject jobj){
    LoadOziApiDll();

    return oziFindOzi();
}
   


int LoadOziApiDll(void)
{


    oziApiDll = LoadLibrary("oziapi.dll");
    if (oziApiDll == NULL)  {return -1;}

    oziFindOzi = (ToziFindOzi)GetProcAddress(oziApiDll,"oziFindOzi");
    if (!oziFindOzi) { FreeLibrary(oziApiDll);return -2;}

    oziLoadWPfile = (ToziLoadWPfile)GetProcAddress(oziApiDll,"oziLoadWPfile");
    if (!oziLoadWPfile) { FreeLibrary(oziApiDll);return -2;}


return 0;

}

And the header is:

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
#include "windows.h"
/* Header for class OZIJava */

typedef int (CALLBACK* ToziLoadWPfile)(char **);
typedef int (CALLBACK* ToziFindOzi)(void);

#ifndef _Included_OZIJava
#define _Included_OZIJava

extern HINSTANCE oziApiDll;
extern ToziFindOzi oziFindOzi;
extern ToziLoadWPfile oziLoadWPfile;
int LoadOziApiDll(void);

#ifdef __cplusplus
extern "C" {
#endif
/*
* Class:     OZIJava
* Method:    joziLoadWPFile
* Signature: (Ljava/lang/String;)I
*/
JNIEXPORT jint JNICALL Java_oziphoto_nat_OZIJava_joziLoadWPFile
 (JNIEnv *, jobject, jstring);

/*
* Class:     oziphoto_nat_OZIJava
* Method:    joziFindOZI
* Signature: ()I
*/
JNIEXPORT jint JNICALL Java_oziphoto_nat_OZIJava_joziFindOZI
 (JNIEnv *, jobject);

#ifdef __cplusplus
}
#endif
#endif

I think that this may have something to do with the finalization of the c++ or delphi stuff. I am not a really good c++ programmer (as you can see). If you re-write my c++ code so it is cleaner and simpler I would appriciate it greatly. I was only cutting and pasting bits out of other c++ examples.

I do not have access to the delphi dll's source.

Regards,

Alistair