EmpFlow – Employee Management System (EMS)

EmpFlow is a Java-based Employee Management System built using JDBC, DAO pattern, and Service layer architecture.
The project focuses on clean separation of concerns, maintainability, and real-world backend design practices.

This system supports user authentication, role management, and employee operations.

---

📌 Key Features

• User authentication (Login)
• Role management
• Employee CRUD operations
• DAO + DAOImpl pattern
• Service layer for business logic
• JDBC-based database interaction
• Maven project structure
• Easily extendable for future features

---

🏗 Architecture Overview

EmpFlow follows a layered architecture:

Main
↓
Controller
↓
Service
↓
DAO
↓
Database

Why this architecture?

• Easy maintenance
• Clear responsibility separation
• Industry-standard backend design
• Easy to add new features

---

📁 Project Structure

EmpFlow-EMS/
│
├── src/
│  └── main/
│  └── java/
│  └── com/company/ems/
|  |
|  ├── controller/
|  |  ├── AuthService.java
│  |  └── EmployeeService.java
│  ├── dao/
│  │  ├── EmployeeDAO.java
│  │  ├── RoleDAO.java
│  │  ├── UserDAO.java
│  │  ├── EmployeeDAOImpl.java
│  │  ├── RoleDAOImpl.java
│  │  └── UserDAOImpl.java
│  │
│  ├── model/
│  │  ├── Employee.java
│  │  ├── Role.java
│  │  └── User.java
│  │
│  ├── service/
│  |  ├── AuthService.java
│  |  └── EmployeeService.java
│  |
|  └── resources
|     ├── db.properies
|     └── schema.sql
|
|
├── pom.xml
├── .gitignore
└── README.md

---

🧩 Package Explanation

model

Contains entity classes:

• Employee – Employee details
• User – Login credentials
• Role – User roles

---

dao

Defines database operation contracts:

• EmployeeDAO
• UserDAO
• RoleDAO

---

dao.impl

Contains JDBC implementations:

• EmployeeDAOImpl
• UserDAOImpl
• RoleDAOImpl

---

service

Contains business logic:

• AuthService
• EmployeeService

---

util

• DBConnection – Manages database connection logic

---

🛠 Technologies Used

• Java (JDK 8+)
• JDBC
• Maven
• PostgreSQL / MySQL
• SLF4J (Logging)
• IntelliJ IDEA

---

🗄 Database Tables

users

Column	Type
id	INT
username	VARCHAR
password	VARCHAR
role_id	INT

---

roles

Column	Type
id	INT
name	VARCHAR

---

employees

Column	Type
id	INT
name	VARCHAR
email	VARCHAR
department	VARCHAR
salary	DOUBLE

---

⚙️ How to Run the Project

1️⃣ Clone Repository

git clone https://github.com/LahiruCodez/EmpFlow-EMS.git
cd EmpFlow-EMS

2️⃣ Configure Database

Update database credentials in db.properties:

String url = "jdbc:postgresql://localhost:5432/empflow-ems";
String username = "postgres";
String password = "your_password";

3️⃣ Build Project

mvn clean install

4️⃣ Run Application

Run the Main class from IntelliJ IDEA.

🔐 Roles & Access

• ADMIN – Full access
• MANAGER – Employee management
• USER – Limited access

🚀 Future Improvements

• Spring Boot migration
• REST APIs
• JWT authentication
• React frontend
• Connection pooling (HikariCP)
• Unit testing with JUnit

---