I'd like to know if it is possible to call an DLL coded in D from Java? I don't have any knowledge on DLL calling mechanism, so I am wondering if this is possible or any special procedure should be followed.

I indeed tried a small example but didn't succeed. First I created an DLL from the template in VisualD as below:

import std.c.windows.windows;
import core.sys.windows.dll;
import std.c.stdio;

__gshared HINSTANCE g_hInst;

extern(C)

export void dllprint() {
	printf("hello dll world\n");
}

extern (Windows)
BOOL DllMain(HINSTANCE hInstance, ULONG ulReason, LPVOID pvReserved)
{
    switch (ulReason)
    {
        case DLL_PROCESS_ATTACH:
            g_hInst = hInstance;
            dll_process_attach(hInstance, true);
            break;

        case DLL_PROCESS_DETACH:
            dll_process_detach(hInstance, true);
            break;

        case DLL_THREAD_ATTACH:
            dll_thread_attach(true, true);
            break;

        case DLL_THREAD_DETACH:
            dll_thread_detach(true, true);
            break;

        default:
            break;
    }
    return true;
}

and its DEF file:

LIBRARY      "z_dll.dll"
EXETYPE NT
SUBSYSTEM WINDOWS
CODE SHARED EXECUTE
DATA WRITE
EXPORTS
	dllprint

I am able to call the generated DLL from D. For calling from Java, I used JNA, and the code is:

public class TestDlangDLL {
	public interface DlangDLL extends Library {

		DlangDLL INSTANCE = (DlangDLL) Native.loadLibrary("C:\\z_dll",
				DlangDLL.class);

		void dllprint();
	}

	public static void main(String[] args) {
		DlangDLL dDLL = DlangDLL.INSTANCE;
		System.out.println(dDLL.toString()); //fine here
		dDLL.dllprint(); //crash on this call
	}
}

This test program is able to load the DLL, but unable to call the exported function dllprint.

Any guidance is appreciated.

On Tue, 16 Jun 2015 18:47:03 -0400, DlangLearner <Bystander@gmail.com> wrote:

> I'd like to know if it is possible to call an DLL coded in D from Java?

What you're looking for is JNI (Java Native Interface).

If you export your D functions correctly, as you have done(extern(C) export) then you can call them the same way you would a C DLL.

This tutorial seems like it may have what you need:
http://www.codeproject.com/Articles/2876/JNI-Basics

  Bit

On 17/06/2015 2:18 p.m., bitwise wrote:
> On Tue, 16 Jun 2015 18:47:03 -0400, DlangLearner <Bystander@gmail.com>
> wrote:
>
>> I'd like to know if it is possible to call an DLL coded in D from Java?
>
> What you're looking for is JNI (Java Native Interface).
>
> If you export your D functions correctly, as you have done(extern(C)
> export) then you can call them the same way you would a C DLL.
>
> This tutorial seems like it may have what you need:
> http://www.codeproject.com/Articles/2876/JNI-Basics
>
>    Bit

Next time I stream at https://www.livecoding.tv/alphaglosined/ I'll be working on a Java parser to make D and Java interop a lot easier in D.
Feel free to drop by and ask questions.

Normally I stream UTC+0 12pm Monday and Tuesday. But might stream tonight. Follow me there or on twitter to get a notification of when I stream.