Create DLL using JNI

[Hunter McMillen]

I am trying to use the Java Native Interface(JNI) to compile and run a simple program. I am following the steps found here: http://java.sun.com/docs/books/jni/html/start.html#27008



I have gone through the first several steps successfully.

1) I created a Java program with appropriate native methods

   public class HelloJNI
{
      private native void print();
      public static void main(String[] args)
      {
         new HelloJNI().print();
      }
      static
      {
         System.loadLibrary("HelloJNI");
      }
   }

2) I called javah -jni on my class file to create the C style header file

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

#ifndef _Included_HelloJNI
#define _Included_HelloJNI
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     HelloJNI
 * Method:    print
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_HelloJNI_print
  (JNIEnv *, jobject);

#ifdef __cplusplus
}
#endif
#endif

3) I wrote the implementation specified by the header in C++

#include <jni.h>
#include <iostream>
#include "HelloJNI.h"
using namespace std;
JNIEXPORT void JNICALL 
Java_HelloJNI_print(JNIEnv *env, jobject obj)
{
  cout << "Hello JNI!" << endl;
  return;
}

4) Now I am at the step when I need to compile the C++ file and generate the .dll
I initially tried running this command:

   cl
     -I"C:\Program Files\Java\jdk1.7.0\include"
     -I"C:\Program Files\Java\jdk1.7.0\include\win32" -MD -LD HelloJNI.cpp
     -FeHelloJNI.dll

but when I ran this I got an error:
C:\Program Files\Java\jdk1.7.0\include\jni.h(39) : fatal error C1083: Cannot open include file: 'stdio.h': No such file or directory

So the command I am trying to run now is:

cl
-I"c:/Program Files (x86)/Microsoft Visual Studio 9.0/Common7/IDE"
-I"c:/Program Files (x86)/Microsoft Visual Studio 9.0/VC/include"
-I"c:/Program Files (x86)/Microsoft Visual Studio 9.0/VC/lib"
-I"c:/Program Files/Java/jdk1.7.0/include" -I"c:/Program Files/Java/jdk1.7.0/include/win32"
-LD HelloJNI.cpp -FeHelloJNI.dll

And When I run this I get:
LINK : fatal error LNK1104: cannot open file 'libcpmt.lib'
Which doesn't make any sense to me beucause 'libcpmt.lib' is on my PATH variable and should be including in the cl command because I point -I to the directory it is in.


Has anyone encountered this issue?
Any help would be great.
Thanks

P.s - I have also posted this question on the Microsoft Visual C++ forum here: http://social.msdn.microsoft.com/Forums/en-AU/vcgeneral/thread/2b79c6f4-eef8-4e85-851f-10a09e725f8f

[Hunter McMillen]

I didn't notice a forum that had JNI specifically listed on the homepage until after I posted this. I will repost there. Sorry for the inconvenience.

Here is the link to the new topic: https://coderanch.com/t/553539/java/java/Create-DLL-JNI#2511261

Hunter