Java TCP Client-Server Wordle

Implementation of the Wordle game using a client-server architecture, communicating over TCP sockets with a custom text-based protocol. The server picks a random 5-letter word, the client has 6 attempts to guess it, and receives letter-by-letter hints after each guess.

Requirements

• Java 18 (JDK)

Project structure

File	Role
WordleServer.java	Server: listens on port 2779 and accepts client connections
WordleClientHandler.java	Handles one game per client (target word, remaining attempts, 20 s timeout)
WordleClient.java	Interactive console client (connects to 127.0.0.1:2779)
WordleProtocol.java	Builds and parses protocol packets
WordleAlgorithm.java	Random word selection and hint computation (handles duplicate letters)
WordleEnum.java	Packet types (TRY, CHEAT, QUIT, GAMEOVER, WRONG, NONEXISTENT, WORD)
WordleWordSet.java	Dictionary of valid words (source)

Build and run

# Compile
javac *.java

# Terminal 1: start the server
java WordleServer

# Terminal 2: start the client
java WordleClient

Client menu:

1) Cheat              -> shows the word to guess
2) Propose a word     -> submit a 5-letter word
3) Quit               -> leave the game

Protocol

Text packets terminated by \r\n.

Client → Server

Packet	Description
TRY <word>	Submit a 5-letter word
CHEAT	Request the word to guess
QUIT	Close the connection

Server → Client

Packet	Description
<hints>	Result of a guess, e.g. BGYBB
<hints> GAMEOVER	End of game (win if GGGGG, otherwise out of attempts)
<WORD>	Response to CHEAT
NONEXISTENT	Word not in dictionary (attempt not counted)
WRONG	Malformed packet

Hints

• G (Green): correct letter, correct position
• Y (Yellow): letter in the word, wrong position
• B (Black): letter not in the word

Limitations

• The server handles clients one at a time: WordleClientHandler implements Runnable but run() is called directly, without a dedicated thread.
• Hardcoded address and port (127.0.0.1:2779).
• A connection idle for 20 seconds is closed (socket timeout).