JDBC Order Management System (Java & MySQL)

A desktop application developed in Java (Swing) for managing clients, products, and orders, utilizing a MySQL database via JDBC and implementing a layered (BLL/DAO) architecture with data validation.

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Key Features

Layered Architecture & Data Access

• Business Logic Layer (BLL): Handles validation and complex operations for Clients, Products, and Orders.
• Data Access Object (DAO): (Assumed to exist alongside BLL classes) Manages all interactions with the MySQL database using JDBC.
• Connection Management: Uses a Singleton pattern (ConnectionFactory) to manage database connections, drivers, and credentials (applicationdb).

Data Validation

All entities are validated before insertion or update using the Strategy pattern (Validator<T> interface):

• Client Validation: Checks for valid email format and a phone number length of exactly 10 characters.
• Product Validation: Ensures price and stock quantity are positive numbers.
• Order Validation: Ensures quantity is positive and the shipping address is not empty.

Order Processing

• Order Creation: Allows users to select an existing client and product via combo boxes, specify a quantity, and provide a shipping address.
• Stock Check: Before placing an order, the system verifies that there is sufficient stock quantity for the requested product.
• Stock Update: Upon successful order placement, the product's stock quantity is reduced accordingly.
• Bill Generation: A new Bill record is automatically created for every successfully placed order, containing client, product, and price details.

CRUD Operations (Client & Product)

• Client Management: Dedicated view for adding, editing (updating selected table row), and deleting clients. Deleting a client also deletes all associated orders.
• Product Management: Dedicated view for adding, editing, and deleting products. Deleting a product is prevented if there are existing orders referencing it.

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Project Structure

• Model: Contains entity classes: Client, Product, Order, and Bill.
• BusinessLogic: Contains the BLL classes (ClientBLL, ProductBLL, OrderBLL) and the validation logic (validators package).
• DataAccess: Contains the DAO classes (not fully provided, but inferred by BLL usage) and ConnectionFactory.
• Presentation: Contains the GUI Views (MainView, ClientView, ProductView, OrderView) and their respective Controllers.

Prerequisites

• Java JDK: Required for compiling and running the application.
• MySQL Database: A running MySQL instance is required.
• Database Setup: A database named applicationdb must exist, configured with tables for Client, Product, Order, and Bill.
• JDBC Driver: The MySQL Connector/J driver must be included in the project's classpath.

How to Run the Project

1. Configure Database: Ensure the database URL, username, and password in Connection.ConnectionFactory.java match your local MySQL configuration.
2. The main execution class is Presentation.MainView.
3. Launch the application to start the main menu GUI.

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