Email OTP Service in Spring Boot

This project demonstrates how to send and verify OTPs (One-Time Passwords) via email using Spring Boot. The application uses Spring Mail for email services and an in-memory store initially

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Features

• Send OTP via email: Users can receive an OTP on their email for verification.
• Verify OTP: The application validates the user-entered OTP against the stored OTP in the database.
• Expire OTPs: OTPs automatically expire after a configured time (e.g., 5 minutes).

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Prerequisites

• Java 11+
• Maven or Gradle for dependency management.
• Spring Boot framework.
• SMTP Email Account (e.g., Gmail, MailTrap, or any other provider).

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Setup Instructions

1. Clone the Repository

git clone https://github.com/amaanalikhan3000/EmailOtp.git
cd email-otp-springboot

2. Configure the Application

Update the application.yml or application.properties file with your email service

Example: application.yml

spring:
  mail:
    host: smtp.gmail.com
    port: 587
    username: your-email@gmail.com
    password: your-email-password
    properties:
      mail:
        smtp:
          auth: true
          starttls:
            enable: true

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3. Build and Run the Application

Build and run the Spring Boot application.

# Using Maven
mvn clean install
mvn spring-boot:run

# Or using Gradle
./gradlew build
./gradlew bootRun

The application will be available at http://localhost:8080.

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Usage

1. Send OTP

Endpoint: POST /api/otp/send
Payload:

{
  "email": "user@example.com"
}

Response:

{
  "message": "OTP sent successfully to user@example.com"
}

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2. Verify OTP

Endpoint: POST /api/otp/verify
Payload:

{
  "email": "user@example.com",
  "otp": "123456"
}

Response (Success):

{
  "message": "OTP verification successful"
}

Response (Failure):

{
  "message": "Invalid or expired OTP"
}

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Project Structure

src/main/java
├── com.email.demo
│   ├── controller
│   │   ├── OtpController.java    # Handles OTP-related API endpoints
│   ├── service
│   │   ├── EmailOtpService.java  # Sends OTP and handles email functionality
│   │   ├── OtpStorageService.java # Manages OTP storage 
│   ├── Entity
│   │   ├── OtpDetails.java       # OTP Details 
│   

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Dependencies

Add the following dependencies to your pom.xml:

<dependencies>
    <!-- Spring Web -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!-- Spring Mail -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-mail</artifactId>
    </dependency>

    <!-- Lombok -->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
</dependencies>

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Security

• OTPs are short-lived and stored in internally with an expiration time.
• Use an App Password for Gmail or secure credentials for your SMTP server.

Troubleshooting

• Email Not Sending: Ensure SMTP settings are correct and your email provider allows less secure app access or uses an App Password.

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License

This project is licensed under the MIT License.