create an object with cni

Hi

I just have a simple programm: One Java class, one C++ class.

Java:
public class Java_with_CNI {

    public Java_with_CNI(){
    }

    public void printHello(){
        System.out.println("Hallo Du, ich wurde durch CNI aufgerufen");
    }
}

and my C++ class:
#include <gcj/cni.h>
#include "Java_with_CNI.h"

class Hallo{
    int main(){
        Java_with_CNI test = new Java_with_CNI::Java_with_CNI();
        test.printHello();
        return 0;
    }
};


This is my first time i use C++, so I dont know whats wrong with my class. I just want to create a new Object (Java_with_CNI) and call the printHello()-method.
What is wrong with my class?

Thank you for your help and best regards
Fabio Bucher