In this section we will write a very simple client-server
application using PolyORB DSA. The server will provide a Remote
Call Interface composed of a single Echo_String function that
will take a String and return it to the caller.
Here is the code for the server:
server.ads:
package Server is
pragma Remote_Call_Interface;
function Echo_String (S : String) return String;
end Server;
server.adb:
package body Server is
function Echo_String (S : String) return String is
begin
return S;
end Echo_String;
end Server;
And here is the code for the client:
client.adb:
------------------------------------------------------------------------------
-- --
-- POLYORB COMPONENTS --
-- --
-- C L I E N T --
-- --
-- B o d y --
-- --
-- Copyright (C) 2011, Free Software Foundation, Inc. --
-- --
-- PolyORB is free software; you can redistribute it and/or modify it --
-- under terms of the GNU General Public License as published by the Free --
-- Software Foundation; either version 2, or (at your option) any later --
-- version. PolyORB is distributed in the hope that it will be useful, --
-- but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHAN- --
-- TABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public --
-- License for more details. You should have received a copy of the GNU --
-- General Public License distributed with PolyORB; see file COPYING. If --
-- not, write to the Free Software Foundation, 51 Franklin Street, Fifth --
-- Floor, Boston, MA 02111-1301, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- PolyORB is maintained by AdaCore --
-- (email: sales@adacore.com) --
-- --
------------------------------------------------------------------------------
with Ada.Exceptions;
with Ada.Text_IO; use Ada.Text_IO;
with Server;
procedure Client is
begin
Put_Line ("The client has started!");
Put ("Thus spake my server upon me:");
Put_Line (Server.Echo_String ("Hi!"));
exception
when E : others =>
Put_Line ("Got " & Ada.Exceptions.Exception_Information (E));
end Client;
For more details about the Distributed Systems Annex, see the Ada Reference Manual [ISO06].