Getting Started with JNI and C under Windows

Question

I'm new in Java learning and first time want to get start JNI. And I am working with Cygwin and I have created a file with .java (Helloworld.java) extension as follows:

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

Then I compile the file through the command line (javac Helloworld.java) after that create a native header file through command javah –jni Helloworld Then also implement by creating a C file as:

#include <jni.h>
 #include <stdio.h>
 #include "HelloWorld.h"

 JNIEXPORT void JNICALL 
 Java_HelloWorld_print(JNIEnv *env, jobject obj)
 {
     printf("Hello World!\n");
     return;
 }

After that while I run the command

 Gcc –wall –g Helloworld.c –o hello 

Give the message in command prompt line in Cygwin

 helloworld.c:1:17: fatal error: jni.h: No such file or directory
 compilation terminated.

How to run and what is the procedure to set the path to execute the file? Please help me any one. Thanks.

Answer 1

I guess you haven't added the jni directory to the include directory list, check http://social.msdn.microsoft.com/forums/is/vclanguage/thread/cd7f2d1d-f750-494c-a3b2-7d4186cfe51c for details.