Redis CRUD API — Spring Boot + Redis

A RESTful CRUD API built with Spring Boot 4 and Redis, demonstrating in-memory data persistence using Redis Hash operations via RedisTemplate. Designed to showcase backend engineering skills with a focus on performance-oriented data storage.

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Tech Stack

Layer	Technology
Framework	Spring Boot 4 (Spring MVC)
Data Store	Redis (via Lettuce client)
Serialization	Jackson (JSON)
Boilerplate Reduction	Lombok
Build Tool	Maven
Language	Java 17

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Architecture Overview

Client
  │
  ▼
UserController        ← REST layer (@RestController)
  │
  ▼
UserDao               ← Data access layer (@Repository)
  │
  ▼
RedisTemplate         ← Spring Data Redis abstraction
  │
  ▼
Redis (Hash)          ← Persistent key-value store (Hash key: "USER")

• RedisConfig — Configures LettuceConnectionFactory and a custom RedisTemplate with StringRedisSerializer for keys and Jackson2JsonRedisSerializer for values.
• UserDao — Encapsulates all Redis Hash operations (opsForHash), keeping Redis logic out of the controller.
• UserController — Thin REST layer that delegates to the DAO and handles HTTP semantics.
• UserModel — Serializable POJO with Lombok annotations, stored as JSON in Redis.

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API Endpoints

Base URL: http://localhost:8080

Method	Endpoint	Description
POST	/users	Create a new user
GET	/users/{userId}	Retrieve a user by ID
GET	/users	Retrieve all users
PUT	/users	Update an existing user
DELETE	/users/{userId}	Delete a user by ID

User Payload

{
  "userId": "auto-generated (UUID)",
  "name": "John Doe",
  "email": "john@example.com",
  "phone": "123-456-7890"
}

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Getting Started

Prerequisites

• Java 17+
• Maven 3.8+
• Redis running locally on port 6379

Start Redis (if using Docker):

docker run -d -p 6379:6379 redis

Run the Application

./mvnw spring-boot:run

Configuration

src/main/resources/application.properties

spring.data.redis.host=localhost
spring.data.redis.port=6379

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Key Implementation Details

• UUID generation is handled server-side in the controller, ensuring clients never need to supply an ID on creation.
• Redis Hash (opsForHash) is used to store all users under a single hash key (USER), enabling O(1) lookups by userId.
• Jackson2JsonRedisSerializer ensures objects are stored as human-readable JSON in Redis rather than binary blobs.
• Lettuce is used as the Redis client (non-blocking, thread-safe, built into Spring Data Redis).
• Serializable model ensures compatibility with Java serialization if needed alongside JSON serialization.

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Project Structure

src/main/java/com/Redis/Implement/
├── Config/
│   └── RedisConfig.java        # Redis connection & template configuration
├── Controller/
│   └── UserController.java     # REST endpoints
├── Dao/
│   └── UserDao.java            # Redis Hash CRUD operations
├── Model/
│   └── UserModel.java          # User entity (Lombok + Serializable)
└── ImplementApplication.java   # Spring Boot entry point

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Sample Requests

Create a user:

curl -X POST http://localhost:8080/users \
  -H "Content-Type: application/json" \
  -d '{"name":"Jane Doe","email":"jane@example.com","phone":"555-0100"}'

Get all users:

curl http://localhost:8080/users

Delete a user:

curl -X DELETE http://localhost:8080/users/{userId}