✅ Crypto Portfolio Tracker (Spring Boot Backend)

A backend application that helps users manage and monitor their cryptocurrency investments. Users can track their coin holdings, view real-time prices, calculate profit/loss, and set up price alerts.

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🎯 Objective

To build a secure and user-friendly backend system where individuals can:

• Add, edit, and delete cryptocurrency holdings
• Track real-time prices using third-party APIs (e.g., CoinGecko)
• View profit/loss calculations for individual coins and total portfolio
• Get alerts when coins hit specific price thresholds

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🧩 Core Features (Explained Simply for Freshers)

🔐 1. User Authentication Module

Purpose: Protect user data and allow secure access.
Functionalities:

• ✅ Register and Login functionality
• ✅ Basic authentication using session_token
• ✅ Each user sees only their holdings

What You’ll Learn:

• How Spring Security works
• Securing API routes using roles
• Session management and validation

📈 2. Holdings Management Module

Purpose: Allow users to record and manage their crypto investments.
Functionalities:

• Add new holdings:
  • Coin Symbol (e.g., BTC)
  • Quantity (how much they own)
  • Buy Price (price when bought)
• Edit and Delete entries
• View current portfolio

What You’ll Learn:

• Building CRUD APIs with Spring Boot
• Using JPA for database operations
• Filtering user-specific data

🌐 3. Real-Time Price Fetcher

Purpose: Keep prices up to date using real market data.
Functionalities:

• Integrate with CoinGecko or similar public APIs
• Fetch latest prices every 5–10 minutes using @Scheduled
• Store prices in a local database or in-memory

What You’ll Learn:

• Making REST API calls with RestTemplate
• Using @Scheduled to run background tasks
• Parsing and mapping JSON to Java objects using Jackson
• Database design for price history

📊 4. Gain/Loss Calculator

Purpose: Show how each holding is performing.
Functionalities:

• For each coin, calculate:
  • gain = (currentPrice - buyPrice) * quantity
  • percentageChange = (gain / (buyPrice * quantity)) * 100
• Show total portfolio profit/loss

What You’ll Learn:

• Writing business logic in service layers
• Performing math operations in Java
• Sending calculated results via REST APIs

🔔 5. Price Alert Module

Purpose: Notify users when their coin hits a target price.
Functionalities:

• Users can set a price alert (e.g., ETH > $3,000)
• The system checks prices on each cron job
• If the condition is met:
  • Mark the alert as “Triggered”
  • Optionally log it or send an email

What You’ll Learn:

• Writing condition-based business logic
• Storing and updating alert status
• Optional: Logging or sending notifications

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⚙️ Tech Stack Overview

Layer	Technology
Language	Java
Framework	Spring Boot, Spring Data JPA
Security	Spring Security, Basic authentication using session_token
Scheduler	Spring Scheduler (@Scheduled)
REST Client	RestTemplate / WebClient
JSON Parser	Jackson
Database	MySQL
Build Tool	Maven

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🧪 API Module Overview

📌 User Controller

• POST /api/auth/register – Register a new user
• POST /api/auth/login – Login and receive token
• PUT /api/users/updateUser/{id} – Update user details
• GET /api/users/getUser/{id} – Get user details by ID
• GET /api/users/getId – Get currently logged-in user's ID

📌 Holdings

• GET /api/holdings/add – Add a new cryptocurrency holding
• POST /api/holdings/getHoldings – Get current user's holdings
• PUT /api/holdings/getMyNetValue – Get total portfolio value for current user

📌 Price Alerts

• POST /api/alert/create – Create a new price alert
• GET /api/alert/user/{userid} – List all alerts
• GET /api/alerts/user/{userid}/triggered – List all triggered alerts
• PUT /api/alert/{id} – Update a price alert
• PUT /api/alert/{id}/disable – Disable a specific alert
• DELETE /api/alert/{id} – Delete a price alert

📌 Admin Controller

• POST /api/admin/login – Login as admin
• GET /api/admin/users – View all users
• GET /api/admin/user/{id} – Get user details by ID (admin access)

📌 Crypto Controller

• GET /api/crypto/getPrice/{symbol} – Get current price of a crypto by symbol
• GET /api/crypto/getAllCryptos – Get list of all supported cryptocurrencies

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Class Diagram

This diagram represents a stock portfolio management system with layers:
Controllers, DTO, Enum, Model, Repository, Services, and Entities.
It includes user authentication, alert generation, portfolio creation, and gain/loss calculation.
Entities like User, PriceAlert, Alert, Holding, and Log manage data and behavior.
Services like PriceService, AlertService, AlertSchedulerService, AdminService, CryptoService, CustomUserDetailsService, EmailService, HoldingService, NotificationService, and UserService provide business logic.

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ER Diagram

This ER diagram models Users, Admins, Holdings, and Logs with relationships among them.

• A User can have multiple Holdings and can generate multiple Logs when transactions occur.
• Holdings store data about the cryptocurrencies owned, such as coin name, quantity, buy price, and price alerts.
• Logs record detailed transaction history including buy/sell prices and dates.
• An Admin can review logs but does not directly manage holdings or users.

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Database Diagram

This database diagram models the core components of a Crypto Portfolio Tracker application, including users, holdings, transaction logs, and external coin data.
It consists of four main tables: users, holdings, logs, and coin_API.

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🧠 Key Concepts for Freshers

Area	What You’ll Learn
Spring Boot APIs	Build and secure backend routes
Security	Basic authentication login using session_token and access control
Scheduling	Automate background tasks like price fetcher
API Integration	Call real-world APIs using Java
JSON Handling	Deserialize API responses with Jackson
Logic & Math	Calculate gains, losses, and percentages
Alerts	Apply business rules (if-else, comparisons)

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🗂 Project Structure

com.example.CryptoPortfolioTracker
├── config
│ └── SecurityConfig.java
├── controller
│ ├── AdminController.java
│ ├── AlertController.java
│ ├── CryptoController.java
│ ├── HoldingController.java
│ └── UserController.java
├── dto
│ ├── AddHoldingRequest.java
│ ├── AlertRequestDTO.java
│ ├── SimpleUserResponse.java
│ ├── CryptoData.java
│ ├── LoginRequest.java
│ ├── HoldingDTO.java
│ └── RegisterRequest.java
├── entity
│ ├── Alert.java
│ ├── Holding.java
│ ├── Log.java
│ └── User.java
├── enums
│ ├── AlertDirection.java
│ ├── AlertStatus.java
│ └── Role.java
├── exception
│ ├── GlobalExceptionHandler.java
│ └── ResourceNotFoundException.java
├── model
│ └── ApiResponse.java
├── repository
│ ├── AlertRepository.java
│ ├── HoldingRepository.java
│ └── LogRepository.java
│ └── UserRepository.java
├── service
│ ├── AdminService.java
│ └── AlertSchedulerService.java
│ ├── AlertService.java
│ ├── CryptoService.java
│ ├── EmailService.java
│ ├── HoldingService.java
│ ├── NotificationService.java
│ ├── PriceService.java
│ └── UserService.java
├── CryptoPortfolioTrackerApplication.java
└── README.md

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🚀 How to Run

✅ Prerequisites

• Java 17+
• Maven
• MySQL
• Postman (for testing APIs)

🧪 Steps

1. Clone the project:
   git clone https://github.com/your-username/CryptoPortfolioTracker.git cd CryptoPortfolioTracker

2. Create a database: CREATE DATABASE CryptoPortfolioTracker;

3. Configure application.properties: spring.application.name=CryptoPortfolioTracker spring.datasource.url=jdbc:mysql://10.9.124.199:3306/CryptoPortfolioTracker?useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true spring.datasource.username=root spring.datasource.password=password spring.jpa.hibernate.ddl-auto=update spring.jpa.show-sql=true spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL8Dialect

   spring.mail.host=smtp-relay.brevo.com spring.mail.port=587 spring.mail.username=[email protected] spring.mail.password=h1nr2WQwZysT5zVg spring.mail.properties.mail.smtp.auth=true spring.mail.properties.mail.smtp.starttls.enable=true

4. Build and run: ./mvnw clean install ./mvnw spring-boot:run

5. Test using Swagger or Postman.

📦 Optional Enhancements

Feature	Benefit
Graphical reports (charts)	Easier to visualize performance
Export portfolio to PDF/Excel	For offline record-keeping
Mobile app integration	Future frontend possibilities
WebSocket price updates	Live price tracking

👩‍💻 Contributors

Name	Role
Praveen	Project Lead, User Module, GlobalExceptionHandling Module, Basic authentication using session_token & Scheduler Logic
Aayushi	Alert module
Kaushik, Harshnie	Price Fetcher, Gain Calculator
Navya	Fetch API Module
Lakshmi Bhanu	Admin Module and Junit testing