Payment Reminder System

A Spring Boot-based web application that helps users keep track of their upcoming, due, and overdue payments. It features OTP-based authentication via email and uses JWT for securing API endpoints.

Features

• User Registration using email and username
• OTP-based Login (No passwords)
• OTP Verification via Email
• JWT Authentication for secure APIs
• Automated Payment Reminders sent via Email:
• 2 days before due date
• On the due date
• After due date (overdue)
• Intelligent backend scheduling using Spring's cron jobs
• Professional HTML email templates for reminders

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Tech Stack

• Backend: Spring Boot, Java
• Authentication: OTP via Email, JWT (JSON Web Token)
• Database: MySQL (configurable)
• Scheduler: Spring @Scheduled with Cron jobs
• Email: JavaMailSender (SMTP)

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Authentication Flow

1. Register with your email and username
2. System sends an OTP to your registered email
3. Enter the OTP to verify and login
4. On successful login, a JWT token is generated and returned
5. Include the JWT token in the browser Cookie (HttpOnly) for all protected endpoints

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Email Reminder Logic

The system sends emails at 9 AM daily for:

• Upcoming Payments: 2 days before the due date
• Due Today Payments: On the due date
• Overdue Payments: Past due date

This is done using a Spring @Scheduled cron job.

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Getting Started

Prerequisites

• Java 17 or later
• Maven
• MySQL installed and running
• SMTP-enabled email (e.g. Gmail)

First Clone the repository

1. Set up the MySQL database:

CREATE DATABASE payment_db;

2. Update application.yml:

• Add your MySQL credentials
• Add your email SMTP details
• Add a secure JWT secret key

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/payment_db
    username: root
    password: <your_sql_password>
    driver-class-name: com.mysql.cj.jdbc.Driver
  jpa:
    show-sql: false
    hibernate:
      ddl-auto: update

  mail:
    host: smtp.gmail.com
    port: 587
    username: <from_email_id>
    password: <app_password>
    properties:
      mail:
        smtp:
          auth: true
          starttls:
            enable: true
JWT_SECRET: <your secret key>

3. Run the project:

./mvnw spring-boot:run

4. Access the app:

http://localhost:8080/auth/register

Testing Paymemt Reminder without Waiting for 9AM

visit this after login

http://localhost:8080/test/reminder