Use native code through JNI (HelloWorld)

Use native code through JNITag(s): JNI

With MSVC6, create a new Win32 DLL project (simple) and call it javahowto.

In the same directory create a java source called JavaHowTo.java

class JavaHowTo {
  public native String sayHello();
  static {
    System.loadLibrary("javahowto"); 
  }
}

Compile the Java program and use javah utility to generate the JavaHowTo.h header file.
```
javah -jni JavaHowTo
```
In MSVC6, add the JavaHowTo.h in your project header files
In the Tools - Options menu, set the include directories to include the Java JNI headers files. They are located in [jdk dir]\include and [jdk dir]\include\win32 directories

In the javahowto.cpp source, add

#include "JavaHowTo.h" 

JNIEXPORT jstring JNICALL Java_JavaHowTo_sayHello
  (JNIEnv *env, jobject obj) {
    return  env->NewStringUTF("Hello world");
}

Select the Release configuration and build the project.
Copy the javahowto.dll in the same directory as the java program.

Create this new java program

public class JNIJavaHowTo {
  public static void main(String[] args) {
    JavaHowTo jht = new JavaHowTo();
    System.out.println(jht.sayHello());
    }
}

Compile and execute.