⚕️ BMI Health – Multi-Health Calculator Web App

A modern JSP + Servlet web application providing BMI, BMR, TDEE, Body Fat %, and Water Intake Calculations.

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📌Overview

TBMI Health is a fully-functional JSP/Servlet-based health calculator web application. It includes calculators for:

• BMI (Body Mass Index)

• BMR (Basal Metabolic Rate)

• TDEE (Total Daily Energy Expenditure)

• Body Fat Percentage (US Navy method)

• Daily Water Intake Calculator

The app follows a professional MVC architecture and includes:

✔ Model classes
✔ Service layer
✔ Input validation
✔ Exception handling
✔ Responsive UI
✔ JUnit5 unit tests

⚙️ Features

🧮 BMI Calculator

• Uses metric & imperial units
• Provides BMI category + tailored health tips
• Input validation & error handling

🔥 BMR & TDEE Calculator

• Add / Update / Delete books
• Search by title, author, subject, ISBN
• Track availability

🧑‍🤝‍🧑 Borrower Management

• Uses Mifflin–St Jeor equation
• Supports activity levels
• Calculates daily caloric needs

💪 Body Fat % Calculator (U.S. Navy Formula)

• Male + Female formulas
• Instant body fat category
• Full explanation & ranges

💧 Water Intake Calculator

• Weight-based formula
• Activity adjustments
• Clean UI display

🎨 Modern UI

• Navbar + Mobile hamburger
• Cards layout
• Fully responsive

🏗️ Technologies Used

Layer	Technologies
Frontend	HTML, CSS, JSP
Backend	Java Servlets, Service Layer
Testing	JUnit5
Build	Maven
Server	Apache Tomcat 9/10
Tools	IntelliJ IDEA

🧩 Architecture Diagram (Mermaid)

graph TD;
    A["JSP Pages (View)"] --> B["Servlets (Controller)"];
    B --> C["Service Layer"];
    C --> D["Models"];
    C --> E["Validators"];

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Project Structure

src/
└── main/
    ├── java/
    │   └── com.github.joel003
    │       ├── controller/   (Servlets)
    │       ├── service/      (Business logic)
    │       ├── model/        (POJOs)
    │       ├── util/         (Validators)
    │       └── exception/    (Custom exceptions)
    │
    ├── resources/
    │
    └── webapp/
        ├── css/
        ├── javascript/
        ├── images/
        ├── bmi-adult.jsp
        ├── bmr.jsp
        ├── bodyfat.jsp
        ├── water.jsp
        └── index.jsp

└── test/
    └── java/
        ├── BMIAdultServiceTest.java
        ├── BMRServiceTest.java
        └── InputValidatorTest.java

🚀 Installation & Setup

1️⃣ Clone the repository

git clone https://github.com/joel-003/BMI-Health-App.git
cd BMI-Health-App

2️⃣ Open in IntelliJ

• File → Open → select project folder
• IntelliJ will auto-import Maven dependencies

3️⃣ Configure Tomcat

• Run → Edit Configurations → Add New → Tomcat Local
• Set deployment to:

Artifacts → BMI-Health-App:war exploded

4️⃣ Run the project

Start Tomcat.

http://localhost:9090/BMI-Health-App/

🧪 Unit Testing (JUnit5)

✔ Tested Modules

Test Suite	Coverage
BMIAdultServiceTest	BMI formula + categories
BMRServiceTest	BMR & TDEE calculations
BodyFatServiceTest	Navy method accuracy
InputValidatorTest	parseDouble, validation rules

Run all tests:

mvn test

▶️ Servlet Endpoints

Page	Servlet	URL
BMI	BMIAdultServlet	/bmi-adult
BMR	BMRServlet	/bmr-calc
Body Fat	BodyFatServlet	/bodyfat-calct
Water	WaterServlet	/water-calc

📸 CLI Screenshots

Click below to view all screenshots:

👉 Open Screenshots Folder

🎬 Run Demo

Below is a short demo of the BMi-Health-App in action:

🛡️ Exception Handling

• The app uses a centralized validation utility:

InputValidator.parseDouble(value, "Height");
InputValidator.validatePositive(height, "Height");

• Custom exception:

throw new InvalidInputException("Invalid input!");

🔮 Future Enhancements

• Dark mode UI

• Add calorie tracking module

• Add export PDF option

• Add mobile PWA support

License

This project is licensed under the MIT License.

See the LICENSE file for full details.

UML Class Diagram

Below is the complete class diagram representing the system architecture.