A multi-threaded dictionary client-server has been designed and implemented in this project, which forms the core of a distributed dictionary system. It enables concurrent clients to access and manage word definitions seamlessly using a thread pool architecture, with communication carried out via sockets. This client-server architecture ensures efficient communication, error resilience, simple encryption and data integrity.
Concurrency and Communication: The server handles multiple client requests simultaneously using a thread pool architecture approach. This optimizes resource utilization and responsiveness, enhancing the user experience.
Network Protocol and Messaging: TCP protocol ensures reliable data transmission between the server and clients. A JSON-based messaging system serves as a universal language for information exchange, facilitating smooth communication.
Error Handling: The server effectively manages I/O and network errors, maintaining system stability even in challenging scenarios. Parameter validation prevents invalid inputs, safeguarding data integrity.
Request Validation: Robust validation prevents clients from making illegal requests. The server identifies and addresses issues like duplicate word addition, non-existent word removal, and adding words without meanings.
Concurrent Data Manipulation: Synchronized operations guarantee data consistency in multi-threaded environments. This eliminates conflicts when multiple clients modify shared resources, ensuring accurate updates.
Scalability: The architecture is built to accommodate numerous clients, adapting to varying demand levels. Thread management optimizes performance, even under heavy loads.
Dictionary Server: The DictionaryServer class acts as the heart of the server-side application. It initializes, listens for incoming client connections, and assigns a dedicated ClientHandler thread for each client. It manages the dictionary data, facilitating operations such as searching for word meanings, adding new words, removing words, and updating meanings based on incoming client requests.
ClientHandler: ClientHandler threads, running independently, are responsible for handling individual client connections. Each thread processes client requests by interacting with the Dictionary class, ensuring that multiple clients can interact with the server concurrently without blocking.
Dictionary: The Dictionary class serves as the storage and management component for dictionary data. It reads the initial dictionary data from a JSON file and maintains it in memory using a JSONObject. This class offers synchronized methods to safely handle concurrent access to the dictionary data.
Dictionary Client: The DictionaryClient class represents the client-side application. It establishes socket connections with the server, enabling communication. This class provides methods for sending client requests and receiving server responses. Additionally, it hosts the main method, initiating the client application by accepting server IP and port as command-line inputs.
DictionaryClientGUI: The DictionaryClientGUI class delivers a user-friendly graphical interface for the client application, created using Java's Swing library. The interface features input fields for various dictionary operations (add, remove, update, search) and displays responses from the server. Interaction with the DictionaryClient class enables request submission and response reception.
DictionaryServerGUI: The DictionaryServerGUI class offers an intuitive graphical interface for the server application. It opens a window presenting a log area that records critical server events, including client connections and responses. The GUI tracks connected clients and showcases their logs in the log area, fostering efficient server monitoring and management.
CustomThreadPool: The CustomThreadPool class introduces a custom thread pool mechanism for managing worker threads efficiently. It allows for the parallel processing of incoming client requests by assigning tasks to available worker threads, improving the server's responsiveness.
CaesarCipher: The CaesarCipher class handles text encryption and decryption, ensuring the security and integrity of messages exchanged between the server and clients. It employs a Caesar cipher algorithm with a predefined shift value to encode and decode messages.