Java H2 Employee Database App

Technologies Used

Overview

This is a Java Swing desktop application for managing employee data. It strictly adheres to the Model-View-Controller (MVC) architectural pattern and uses JPA/Hibernate for database interactions with an embedded H2 database.

Architecture (MVC Pattern)

• Model: Consists of an Employee.java JPA Entity class, an EmployeeRepository.java for direct database operations using JPA’s EntityManager, and an AppModel.java. The AppModel holds the list of employees and crucially uses PropertyChangeSupport to notify the view of data changes, implementing the Observer pattern.
• View: Comprises two Swing forms: AppView.java, the main window with a JTable to display employees, and InsertView.java, a dialog for adding/editing records. AppView registers as a PropertyChangeListener to the AppModel to enable automatic UI updates.
• Controller: The AppController.java acts as the mediator. It handles user interactions from the views (button clicks), translates them into model operations (e.g., calling appModel.persist()), and manages the visibility of the different views.

Key Features

• Strict MVC Implementation: Clear separation of concerns between data, presentation, and control logic.
• Dynamic UI Updates: The main employee list automatically refreshes when data changes, thanks to the observer pattern implementation.
• JPA/Hibernate Integration: Uses modern ORM practices for database interaction, configured via persistence.xml.
• Database Seeding: On the first run, the application automatically populates the H2 database with 20 sample employee records.