nikolaiunknown/tictactoe-server

Purpose and Runtime

Spring Boot 3.5 / Java 21 backend for authenticated, real-time multiplayer Tic-Tac-Toe. It exposes REST for identity, game/history/profile operations and STOMP WebSocket for live play. Application bootstrap is src/main/java/com/tictactoe/server/ServerApplication.java; runtime settings, including game disconnect/rating parameters and JWT lifetime, are in src/main/resources/application.yaml.

Transport Entry Points

REST requests enter through src/main/java/com/tictactoe/server/controllers/AuthController.java, src/main/java/com/tictactoe/server/controllers/GameController.java, and src/main/java/com/tictactoe/server/controllers/PlayerController.java. Live client moves enter the WebSocket controller/handler pair at src/main/java/com/tictactoe/server/controllers/GameHandler.java and src/main/java/com/tictactoe/server/config/WebSocketConfig.java, using the documented /ws/connect endpoint and /app/game/move mapping. Separate global handlers normalize REST and WebSocket failures.

Authentication and Authorization Boundary

Spring Security protects HTTP and messaging traffic. JWT creation/validation is centered on src/main/java/com/tictactoe/server/security/JwtCore.java; HTTP bearer-token processing uses src/main/java/com/tictactoe/server/security/JwtTokenFilter.java, while STOMP connection/message authentication uses src/main/java/com/tictactoe/server/security/AuthenticationChannelInterceptor.java. Access and persisted refresh-token lifecycle flow through src/main/java/com/tictactoe/server/services/RefreshTokenService.java and src/main/java/com/tictactoe/server/models/RefreshToken.java.

Persistent Domain and Service Layer

MySQL-backed JPA entities represent players, games, and refresh tokens in src/main/java/com/tictactoe/server/models/Player.java, src/main/java/com/tictactoe/server/models/Game.java, and src/main/java/com/tictactoe/server/models/RefreshToken.java. Repositories isolate persistence; service implementations own business workflows: game creation/cancellation and history, player profiles/statistics/ELO, and token management. DTO/mapping boundaries prevent entities from being direct API contracts, notably src/main/java/com/tictactoe/server/mappers/GameMapper.java and src/main/java/com/tictactoe/server/mappers/PlayerMapper.java.

Live Game State and Move Processing

The in-memory gameplay/session layer is distinct from persisted game records. src/main/java/com/tictactoe/server/core/GameCore.java holds board/rule logic, src/main/java/com/tictactoe/server/core/GameSession.java represents an active match, and src/main/java/com/tictactoe/server/services/GameSessionService.java coordinates session lifecycle. A move flows from STOMP handler to src/main/java/com/tictactoe/server/services/GameMoveService.java, where participant, turn, board-cell, and game-status validation precede state mutation, result handling, and game/player persistence updates.

Matchmaking, Messaging, and Disconnect Lifecycle

Unstarted games/invitations and disconnected participants are managed independently by src/main/java/com/tictactoe/server/core/UnstartedGamesManager.java and src/main/java/com/tictactoe/server/core/DisconnectedPlayersManager.java. Outbound game/session/proposition messages are published through src/main/java/com/tictactoe/server/services/WebSocketMessagingService.java; message caching supports connection/session continuity via src/main/java/com/tictactoe/server/services/MessageCacheService.java. src/main/java/com/tictactoe/server/utils/WebSocketEventListener.java observes connection events, while src/main/java/com/tictactoe/server/utils/ScheduleTasks.java enforces delayed disconnect cancellation.

Infrastructure

Gradle builds and runs the service (build.gradle), and Dockerfile packages it for container deployment. Material external dependencies are MySQL via Spring Data JPA/Hibernate and client WebSocket/STOMP connections; there is no separate broker or cache service indicated by the repository.