🛡️ Secure Notes Application

Enterprise-Grade Security Meets Intelligent Note-Taking.

Secure Notes is a full-stack, highly secure note-taking application designed to provide users with a private, collaborative, and data-driven environment. Built with modern software engineering principles, it goes beyond basic CRUD operations by integrating advanced behavioral analytics, optimistic locking for real-time collaboration, and proactive security monitoring.

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✨ Core Features & Complex Logic

This project implements three major Complex Logic (CL) components that demonstrate advanced algorithmic design, data-driven decision making, and multi-step workflows.

1. Data-Driven Activity Analysis (CL-1)

• Iterative Streak Detection: A custom algorithm calculates user engagement by tracking consecutive days of note creation.
• Dynamic Rule Evaluation: Evaluates user metrics (e.g., average character count, total notes) against predefined thresholds to generate activity insights.
• Real-Time Dashboard: Displays analytics directly to the user, turning raw database metrics into actionable visual data.

2. Collaborative Editing & Conflict Resolution (CL-2)

• Optimistic Locking: Implements a "Latest Wins + Version History" strategy to handle concurrent modifications by multiple users on the same note.
• Data Preservation: If a version conflict is detected, the system archives the previous version to a NoteHistory table before applying the new state, ensuring zero data loss.
• Third-Party Integration: Automatically triggers a formatted HTML email via JavaMailSender to notify users when they have been invited to collaborate.

3. Security-Oriented Behavior Monitoring (CL-3)

• Context-Aware Authentication: Tracks and logs sensitive security events like failed logins and password reset requests.
• Temporal Thresholds: Evaluates user behavior over time (e.g., limiting password resets to 3 per hour).
• Automated Mitigation: Applies conditional branching to trigger controlled responses, such as temporary account restrictions or warning states, actively preventing brute-force attacks.

🔒 Additional Security Features

• Stateless Authentication: JSON Web Tokens (JWT) for secure session management.
• Password Cryptography: BCrypt hashing and salting for all stored credentials.
• Audit Logging: Comprehensive tracking of note creation, updates, and deletions.
• Role-Based Access Control (RBAC): Strict separation between standard Users and System Administrators.

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🛠️ Tech Stack

Frontend (Client-Side)

• React.js - UI Library
• Tailwind CSS - Utility-first styling
• Framer Motion - Advanced UI animations
• Material UI (MUI) - Data grids and tooltip components
• Axios - API communication

Backend (Server-Side)

• Java 17 & Spring Boot 3 - Core backend framework
• Spring Security & JWT - Authentication and authorization
• Spring Data JPA (Hibernate) - ORM and database management
• JavaMailSender - Automated email dispatch

Database

• MySQL / PostgreSQL - Relational data storage

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📂 Project Architecture

This repository uses a monorepo structure containing both the frontend and backend environments:

Secure_Notes/
├── backend/                  # Spring Boot Application
│   ├── src/main/java/...     # Controllers, Models, Repositories, Services
│   ├── src/main/resources/   # application.properties, static assets
│   └── pom.xml               # Maven dependencies
│
└── frontend/                 # React Application
    ├── public/               # index.html, manifest
    ├── src/                  # Components, Context API, utils
    ├── package.json          # Node dependencies
    └── tailwind.config.js    # Tailwind configuration

🚀 How to Run the Project Locally

Prerequisites Before you begin, ensure you have the following installed on your machine:

Java Development Kit (JDK) 17 or higher

Node.js (v16 or higher) and npm

MySQL Server (Running locally on port 3306)

A code editor (IntelliJ IDEA for backend, VS Code for frontend)

Step 1: Database Setup Open your MySQL client (e.g., MySQL Workbench).

Create a new database named securenotes:

SQL CREATE DATABASE securenotes;

Step 2: Backend Setup Open your terminal and navigate to the backend folder:

Bash cd backend Open src/main/resources/application.properties and configure your credentials:

Properties

MySQL Credentials

spring.datasource.username=YOUR_MYSQL_USERNAME spring.datasource.password=YOUR_MYSQL_PASSWORD

Email Configuration (For Collaboration & Password Resets)

spring.mail.username=YOUR_GMAIL_ADDRESS spring.mail.password=YOUR_GMAIL_APP_PASSWORD

JWT Secret (Generate a strong 256-bit string)

spring.app.jwtSecret=YOUR_SUPER_SECRET_JWT_KEY Run the Spring Boot application:

Bash ./mvnw spring-boot:run (The backend server will start on http://localhost:8080)

Step 3: Frontend Setup Open a new terminal window and navigate to the frontend folder:

Bash cd frontend Install the necessary Node modules:

Bash npm install Start the React development server:

Bash npm start (The application will automatically open in your browser at http://localhost:3000)

🤝 Usage Guide

Sign Up: Create a new account via the /signup route.

Create a Note: Use the Rich Text Editor to format and save a secure note.

Collaborate: Click the "Share" icon on any of your notes and enter a colleague's email. They will receive an automated email invitation.

Test Conflict Resolution: Open the shared note in two different browsers. Edit them simultaneously and watch the backend archive the older version to the NoteHistory table while accepting the newest edit.

View Analytics: Navigate to the "My Notes" dashboard to see the live output of the CL-1 Activity Algorithm.