Project for implementing a multi-user chat tool

Licence 3 Informatique - Modules Systèmes Distribués / Systèmes d'Exploitation II

Université de Pau et des Pays de l'Adour

May 2024

Table of Contents

1. Objective
2. Working Folder
3. Project Compilation
   • Compilation of the Account Management section
   • Compilation of the Central Part section
   • Compilation of the Client section
4. Running the application
   • Starting the Server
   • Starting the Client
5. Using the Application
   • Client Part
   • Server Part
6. Tools and Extensions Used

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Note : The project documentation is written in French.

Objective

This project involves developing a multi-user chat application based on a client-server architecture and operating in a distributed mode. The application enables :

• User authentication through an account management system.
• Message exchange between multiple clients connected simultaneously.
• Management of connections and disconnections, with real-time updates of the active user list.
• A command-line interface for both the client and the server.

The project implements various inter-process communication mechanisms, including TCP/UDP sockets, Java RMI, as well as process synchronization techniques (threads, semaphores, shared memory).

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Working Folder

A working folder has been created :

• Working Folder [PDF]

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Project Compilation

Although the project's executables are provided, here are the different compilation commands for the necessary files :

Compilation of the Account Management section

cd Gestion_comptes
javac GestionComptes.java

Generate the stub for GestionComptes.class (for using Java RMI), and copy it into the Partie_centrale folder.

cd Gestion_comptes
rmic GestionComptes
cp GestionComptes_Stub.class ../Partie_centrale

Compilation of the Central Part section

cd Partie_Centrale
javac ClientRMI.java
gcc -o Gestion_requete Gestion_requete -pthread -lrt
gcc -o Communication Communication.c -pthread -lrt
gcc -o Main Main.c -lrt

Compilation of the Client section

cd Client
gcc -o Afficheur_chat Afficheur_chat.c
gcc -o Client_chat Client_chat.c -pthread

Note :
The -pthread option links the program to the pthread library, enabling the use of threads.
The -lrt option links the program to the librt library, facilitating the use of time-related functionalities, particularly in the context of shared memory.

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Running the application

Starting the Server

Account Management section

cd Gestion_Comptes
rmiregistry &
java GestionComptes

Central Part section

cd Partie_centrale
./Main <nom_serveur_gestion_comptes> <numero_port>

To run the Main file, you need to specify the machine name where the GestionComptes process is running (IP addr or hostname) and a listening port consisting of 4 digits.

Starting the Client

To start a client, you need to know the name of the Main server (IP addr or hostname) and the port number (specified above):

cd Client
./Client_chat <nom_serveur_main> <numero_port>

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Using the Application

Client Part

Once connected to the system, the client initially has three options :

• Connect
• Create an account
• Quit

The accounts are saved in the listeComptes.txt file with a pseudonym and password.

Once authenticated, the user can access several features :

• View online users
• Send a message
• Disconnect
• Quit

Simultaneously, a terminal opens to display received messages. If the user chooses to disconnect, they will be redirected to the initial login menu. The program stops when the user exits the system using the provided quit feature or by pressing the CTRL+C combination.

Server Part

In the terminal running Main, the Communication program indicates the status of the server (connection status, port number, etc.) and interprets the requests sent, displaying the type of request (connection, disconnection, user list, message, etc.), as well as the positive or negative response. This display is useful in case of system malfunctions and helps pinpoint the exact issue.

It is possible to stop the server intentionally by using the CTRL+C combination or by typing the exit command in the terminal of the Main in the central part.

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Tools and Extensions Used

• Java RMI License : It is part of the Java programming language and is subject to the licensing of the Java Development Kit (JDK). The JDK by Oracle is distributed under the Oracle Binary Code License (BCL) for commercial use. However, OpenJDK, which is an open-source implementation of Java, is distributed under the GNU General Public License (GPL) version 2 with the Classpath Exception.

May 2024