Overview

FTP-WIRE follows a modular client-server architecture which separates concerns between command processing, data transfer, and connection management. The system is composed of two primary modules: a Server and a Client — which communicate using structured packet-based messages over TCP sockets.

High Level Diagram

graph TD
    classDef default rx:15, ry:15;

    %% --- SERVER SIDE ---
    subgraph ServerSide["Server"]
        ServerModule["Server Module"]
    end

    %% --- CLIENTS SIDE ---
    subgraph Client1["Client 1"]
        Client1UI["Client UI"]
        Client1Module["Client Module"]
        Client1UI --> Client1Module
    end

    subgraph Client2["Client 2"]
        Client2UI["Client UI"]
        Client2Module["Client Module"]
        Client2UI --> Client2Module
    end

    %% --- CONNECTIONS BETWEEN CLIENTS AND SERVER ---
    Client1 <-->|Commands / Replies| ServerSide
    Client2 <-->|Commands / Replies| ServerSide

A Server Module is used to act as a central service for many clients. Each of those clients has a Client UI which could be different such as a CLI or a GUI application that integrates ftp-wire. Each client should be able to operate with the server separately, regardless of other clients errors or disconnections.

The FTP Model

The Server/Client architecure follows the FTP-Model design which is shown as follows

flowchart LR
    classDef rounded rx:15, ry:15;


    User-->|Interaction|UI
    Client<-->user-storage["FileSystem"]
    subgraph User-FTP
        UI<-->|Control|Client
    end


    subgraph Server-FTP
        Server
    end
    Server<-->server-storage["FileSystem"]
    Server-FTP<-->|Command Connection|User-FTP
    Server-FTP<-->|Data Connection|User-FTP

    class User,UI,Client,user-storage,Server,server-storage rounded;

Project Structure

The Client Module is represented with the Client package, same for the Server Module. Each of the two modules has many other submodules, each one is providing a specific functionality. There are many common submodules between the Client and the Server modules which are located in the Common package

ftp-wire

Client

Controllers

• CommandController.java
• DataController.java

Loggers

• ClientLogger.java

ReplyHandlers

• FILE_INFO_ReplyHandler.java
• MESSAGE_ReplyHandler.java
• ReplyHandler.java
• CWD_ReplyHandler.java
• PWD_ReplyHandler.java

Models

• ClientConfig.java
• CommandSender.java
• ConnectionManager.java
• LoggerManager.java
• Reply.java
• ReplyPacketFactory.java
• ResponseReceiver.java

• Client.java

clientCLI

• ClientCLI.java
• ClientCLILogger.java
• CommandHandler.java
• OfflineClientCLI.java
• OfflineCommandType.java

Common

Exceptions

• CommandFormatException.java
• NoCommandWithSpecifiedHeaderException.java
• RemoteDisconnectionException.java

Loggers

• Logger.java

Models

• Command.java
• Status.java
• UtilityFunctions.java

Packets

Communication

• CommandPacket.java
• ReplyPacket.java

HandShaking

• DonePacket.java
• HelloPacket.java
• PairPacket.java
• WelcomePacket.java

IO

• PacketReader.java
• PacketWriter.java

• Packet.java

Serialization

• PacketSerializer.java

Types

• PacketType.java
• ReplyType.java

Server

Exceptions

• CanNotReadPacketException.java

Handlers

• ChangeWorkingDirectoryHandler.java
• CommandErrorHandler.java
• CommandHandler.java
• ErrorHandler.java
• HelpCommandHandler.java
• ListFilesCommandHandler.java
• PrintWorkingDirectoryHandler.java
• QuitCommandHandler.java
• RetrieveFileCommandHandler.java

HandShaking

• HandShakeManager.java
• Session.java

Loggers

• ServerCLILogger.java
• ServerLogger.java

Models

Types

• CommandType.java
• ErrorType.java

• ClientProfile.java
• CommandSelectorDispatcher.java
• ServerConfig.java
• TaskDispatcher.java
• ThreadPool.java
• UserConnection.java

Registeries

• SessionRegistry.java

SocketAcceptors

• CommandSocketAcceptor.java
• DataSocketAcceptor.java

Tasks

• CommandTask.java
• DataTask.java
• SendFileTask.java
• SendPacketTask.java
• Task.java

• Server.java

Run

• Client_CLI.java
• Server_CLI.java

Data/Connection flow

The Client first will do a handshaking process which will identify his connection info and username then if the client connection success (for now there is no login functionality), he can send a command to the server then the server will schedule a task to serve that command. After the task is completed, the server schedule another task for sending a reply packet to the client which will identify the success or failure of the sent command. this also could be followed by sending a file from the server to the client through the Data Connection.

sequenceDiagram
    participant C as Client
    participant S as Server
    participant H as Handler

    C<<->>S: HandShaking process
    C->>S: Send CommandPacket
    S->>H: Dispatch Command
    H-->>S: Generate ReplyPacket
    S-->>C: Send ReplyPacket