cni-3.txt

[RefuX Zanzeebarr]

updated http://gcc.gnu.org/java/cni-2.txt for 3.3.4

cni-3.txt
Here is a sample project demonstrating the basics of building a CNI
application with GCJ version 3.3.4.

It assumes that you have installed the binaries in a directory
in your path.

==> Makefile <==
sample:  sample.o sampNat.o
        gcj -o sample \
                sample.o sampNat.o -lstdc++ --main=sample

sample.o:  sample.class
        gcj -c sample.class

sample.class: sample.java
        gcj -C sample.java

sample.h: sample.class
        gcjh sample

sampNat.o: sample.h sampNat.cc
        g++ -c sampNat.cc

clean:
        rm -f sample sample.o sampNat.o sample.class sample.h

==> sample.java <==
public class sample {
  public native void myNative(String s);

  public void myJava(String s)
  {
    s = s + ", Java";
    System.out.println(s);
  }

  public static void main(String args[]) {
    sample x = new sample();
    x.myJava("Hello");
    x.myNative("Hello, Java (from C++)");
    x.myJava("Goodbye");
  }
}

==> sampNat.cc <==
#include <gcj/cni.h>
#include "sample.h"
#include <java/io/PrintStream.h>
#include <java/lang/System.h>
#include <java/lang/String.h>

#include <iostream>
using namespace std;

void sample::myNative(java::lang::String *s)
{
  cout << "Hello, C++" << endl;

  java::lang::System::out->println(s);
}