Anadi Misra

• Nov 13th, 2005

 

to use jni we need three things one a native library , usually a ".DLL" which is complied in C or C++. a header file for the native library and the java code whre native aPI implementation is called.

 a method that calls the native librbary will also be requiered to have "native" keyword  in its signature.

eg. public native void nHello(){.............}

we can then call the native method in this method of java

i.e. public native void nHello(){hello();}

the source file is then compiled as usual and the classfile is used with javah command to generate a header file which will have the name same as the class file

javah <Class Name>

the method when implemented for example in c must include jni.h file

found in %java_home%\include\win32 folder

i.e.

#include "jni.h"

# include "<CLass Name>.h"

void hello(){

printf("Hello World !");

}