Employee Management System

This is a simple Employee Management System built using Java and SQL. The project follows a layered architecture pattern, which includes the following layers:

1. Domain Layer: This layer contains the Employee class, which is a simple Java class that represents the Employee entity in our application.

2. DAO Layer: This layer is responsible for interacting with the database. It contains the EmployeeDao interface and its implementation EmployeeDaoImpl. The EmployeeDao interface extends the Dao interface, which defines the basic CRUD operations. The EmployeeDaoImpl class implements these operations using JDBC.

3. Service Layer: This layer contains the EmployeeService interface and its implementation EmployeeServiceImpl. The EmployeeService interface defines the same CRUD operations as the Dao interface. The EmployeeServiceImpl class implements these operations by delegating the work to an instance of EmployeeDao.

4. Controller Layer: This layer contains the EmployeeController class, which is responsible for handling user requests and delegating the work to the EmployeeService.

5. Main Application: This is the entry point of our application. It uses the EmployeeController to perform CRUD operations on Employee entities.

How Each Layer Interacts with the Other

• The Main Application interacts with the Controller Layer. It creates an instance of EmployeeController and uses it to perform CRUD operations on Employee entities.

• The Controller Layer interacts with the Service Layer. The EmployeeController has an instance of EmployeeService, which it uses to perform CRUD operations. When the EmployeeController receives a request from the Main Application, it delegates the work to the EmployeeService.

• The Service Layer interacts with the DAO Layer. The EmployeeServiceImpl has an instance of EmployeeDao, which it uses to interact with the database. When the EmployeeServiceImpl receives a request from the EmployeeController, it delegates the work to the EmployeeDao.

• The DAO Layer interacts with the Database. The EmployeeDaoImpl uses JDBC to execute SQL queries against the database.

• The Domain Layer is used by all other layers. The Employee class is used to represent Employee entities throughout the application.

How to Run the Application

1. Clone the repository.
2. Open the project in your favorite IDE (the project is set up for IntelliJ IDEA).
3. Make sure you have a MySQL server running and adjust the database connection parameters in the Database class if necessary.
4. Run the Main class.

Please note that this is a simple example and does not include any error handling or input validation. It's meant to demonstrate the basic structure of a layered architecture in a Java application.