🚀 User Management System

A modern RESTful API for user management built with Spring Boot

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📋 Table of Contents

• ✨ Features
• 🛠️ Technologies
• 🚀 Getting Started
• 📡 API Endpoints
• ✅ Validation Rules
• 🔧 Error Handling
• 🤝 Contributing

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✨ Features

Clean RESTful APIs for seamless user management

• 📋 List Users: Retrieve all users with a single GET request
• 👤 Create Users: Add new users with comprehensive validation
• 🛡️ Data Validation: Robust input validation with detailed error messages
• 🔄 Exception Handling: Graceful error handling with meaningful responses

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🛠️ Technologies

Backend
Data Layer
Build Tool

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🚀 Getting Started

📋 Prerequisites

Ensure you have the following installed:

Requirement	Version	Download
☕ Java	17+	Oracle JDK / OpenJDK
🔧 Maven	3.6+	Apache Maven
💻 IDE	Latest	IntelliJ IDEA / VS Code

📦 Installation

🔽 Click to expand installation steps

1️⃣ Clone the Repository

git clone https://github.com/khan-sk-dev/user-management.git
cd user-management

2️⃣ Build the Project

mvn clean install

3️⃣ Run the Application

mvn spring-boot:run

4️⃣ Verify Installation

🌐 Open your browser and navigate to: http://localhost:8080

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📡 API Endpoints

🔍 Overview

Method	Endpoint	Description	Status
GET	/users	Retrieve all users	✅ Available
POST	/users	Create a new user	✅ Available

📝 Create User Example

📤 POST /users

Request:

POST /users
Content-Type: application/json

{
  "id": 1,
  "name": "John Doe",
  "email": "john.doe@example.com"
}

Response:

HTTP/1.1 201 Created
Content-Type: application/json

{
  "id": 1,
  "name": "John Doe",
  "email": "john.doe@example.com",
  "createdAt": "2025-05-19T10:30:00Z"
}

📋 GET /users

Request:

GET /users

Response:

HTTP/1.1 200 OK
Content-Type: application/json

[
  {
    "id": 1,
    "name": "John Doe",
    "email": "john.doe@example.com",
    "createdAt": "2025-05-19T10:30:00Z"
  },
  {
    "id": 2,
    "name": "Jane Smith",
    "email": "jane.smith@example.com",
    "createdAt": "2025-05-19T11:15:00Z"
  }
]

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✅ Validation Rules

Field	Rules	Example
🆔 ID	≥ 0 (zero or positive)	1, 42, 0
👤 Name	2-255 characters • not blank	"John Doe"
📧 Email	valid format • not empty	"user@domain.com"

🔍 Validation Examples

✅ Valid User Data

{
  "id": 0,
  "name": "Al",
  "email": "al@example.com"
}

❌ Invalid User Data

{
  "id": -1,           // ❌ Negative ID
  "name": "A",        // ❌ Too short (< 2 chars)
  "email": "invalid"  // ❌ Invalid email format
}

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🔧 Error Handling

The API provides detailed error responses for better debugging:

❌ Validation Error Response

HTTP/1.1 400 Bad Request
Content-Type: application/json

{
  "timestamp": "2025-05-19T10:30:00Z",
  "status": 400,
  "error": "Bad Request",
  "message": "Validation failed",
  "path": "/users",
  "fieldErrors": {
    "id": "ID must be zero or positive",
    "name": "Name must be between 2 and 255 characters",
    "email": "Email must be a valid email address"
  }
}

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🤝 Contributing

We welcome contributions! 🎉

📝 How to Contribute

1. 🍴 Fork the repository
2. 🌿 Create a feature branch: git checkout -b feature/amazing-feature
3. 💾 Commit your changes: git commit -m 'Add some amazing feature'
4. 📤 Push to the branch: git push origin feature/amazing-feature
5. 🔄 Open a Pull Request

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Built with ❤️ using Spring Boot