🚀 Spring Boot API Rate Limiter

A lightweight API Rate Limiter built using Java and Spring Boot to protect backend services from excessive API requests.

This project limits the number of requests a client can make within a fixed time window, preventing API abuse and improving backend stability.

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🌐 Live API

Test the deployed API here:

https://springboot-api-rate-limiter.onrender.com/api/test

Refresh the page multiple times to see the rate limiter blocking excessive requests.

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✨ Features

✔ API Request Rate Limiting ✔ Lightweight In-Memory Implementation ✔ Prevents API abuse ✔ REST API endpoint for testing ✔ Dockerized application ✔ Cloud deployed backend

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🛠 Tech Stack

Technology	Usage
Java 17	Programming Language
Spring Boot	Backend Framework
Maven	Build Tool
Docker	Containerization
Render	Cloud Deployment
REST API	API Architecture

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📂 Project Structure

springboot-api-rate-limiter
│
├── src
│   ├── main
│   │   ├── java
│   │   │   └── api_rate_limiter
│   │   │       ├── controller
│   │   │       │   └── ApiController.java
│   │   │       │
│   │   │       ├── service
│   │   │       │   └── RateLimiterService.java
│   │   │       │
│   │   │       └── ApiRateLimiterApplication.java
│   │   │
│   │   └── resources
│   │       └── application.properties
│
├── Dockerfile
├── pom.xml
└── README.md

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🏗 Architecture Diagram

Client / Browser
        │
        │ HTTP Request
        ▼
Spring Boot Controller
(ApiController)
        │
        ▼
RateLimiterService
(Request Counting Logic)
        │
        ▼
Response
(API Allowed / Blocked)

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🔄 API Request Flow

Client Request
      │
      ▼
Check Request Count
      │
      ├── Within Limit
      │        │
      │        ▼
      │   Allow Request
      │
      └── Limit Exceeded
               │
               ▼
        Block Request

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🌐 API Endpoint

Test Endpoint

GET /api/test

Example:

https://springboot-api-rate-limiter.onrender.com/api/test

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📥 Example Response

Successful Request

API request successful 🚀

Limit Exceeded

Too many requests ❌

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🐳 Docker Deployment

The application is containerized using Docker and deployed on Render.

Dockerfile used:

FROM maven:3.9.6-eclipse-temurin-17 AS build
WORKDIR /app
COPY pom.xml .
COPY src ./src
RUN mvn clean package -DskipTests

FROM eclipse-temurin:17-jdk
WORKDIR /app
COPY --from=build /app/target/*.jar app.jar
ENTRYPOINT ["java","-jar","app.jar"]

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▶ Run Locally

Clone repository

git clone https://github.com/ChinmayaKumarSingh/springboot-api-rate-limiter.git

Navigate to project

cd springboot-api-rate-limiter

Run application

mvn spring-boot:run

Open browser

http://localhost:8080/api/test

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📈 Future Improvements

• Redis based distributed rate limiter • User based request tracking • Swagger API documentation • Request logging and monitoring • Rate limiting per API endpoint

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👨‍💻 Author

Chinmaya Singh

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📜 License

This project is licensed under the MIT License.

Copyright (c) 2026 Chinmaya Kumar Singh

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⭐ If you found this project useful, please consider giving it a star on GitHub.