📦 Kafka Spring Boot Producer-Consumer Example

🚀 Project Overview

This project demonstrates the power and simplicity of integrating Apache Kafka with Spring Boot for asynchronous, high-throughput messaging.

Imagine a Delivery Boy Microservice sending 1,00,000 messages 📦 (orders, locations, updates etc.), while the End User Service consumes them instantly — real-time and scalable.

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🛠 Tech Stack

• Java 17
• Spring Boot Web
• Spring Kafka
• Postman (for testing the producer API)

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📚 Features

• REST API endpoint to publish messages to Kafka.
• Kafka consumer to process and log those messages.
• Can simulate a large number of messages (e.g., 1,00,000) efficiently.
• Easy to extend for real-time systems like food delivery, logistics, etc.

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📦 Dependencies

dependencies {
	implementation("org.springframework.boot:spring-boot-starter-web")
	implementation("org.springframework.kafka:spring-kafka")
	testImplementation("org.springframework.boot:spring-boot-starter-test")
	testImplementation("org.springframework.kafka:spring-kafka-test")
	testRuntimeOnly("org.junit.platform:junit-platform-launcher")
}

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📥 Kafka Consumer

• Automatically listens on the configured topic.
• Logs messages in real-time as they arrive.

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🧪 Running the Project

▶️ Start Kafka (if not embedded)

Make sure Kafka is running locally on default port (9092) or configure it in application.yml.

▶️ Run Spring Boot

./gradlew bootRun

▶️ Hit the producer endpoint from Postman

Send a POST request to http://localhost:8080/location/update

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📈 Sample Logs

Location sent to kafka topic (23, 55)
Location sent to kafka topic (45, 56)
...
Location sent to kafka topic (34, 67)