Using Redis with Spring Boot application in Docker

This is a small Spring Boot application that utilizes Redis for caching layer. Under the hood, the application sends requests to the public API http://jsonplaceholder.typicode.com, and it caches the data for the subsequent requests.

For example, when we send a GET request to

http://localhost:8080/posts/{id}

basically it checks the Redis Cache if it has a key which is a string of the id of the Post. If indeed, there is such a key, it returns the value of that key. In our situation is a string of the following JSON object,

{
    "userId": 1,
    "id": 1,
    "title": "sunt aut facere repellat provident occaecati excepturi optio reprehenderit",
    "body": "quia et suscipit\nsuscipit recusandae consequuntur expedita et cum\nreprehenderit molestiae ut ut quas totam\nnostrum rerum est autem sunt rem eveniet architecto"
}

On the other hand, if the Redis cache does not have the key (which this is the case for the first time the application starts), it sends a GET request to

http://jsonplaceholder.typicode.com/posts/1

and stores the value for the subsequent calls.

In each request, we are calculating the elapsed time. For HTTP calls we get a time of some hundreds ms. However, with Redis those calls are less than 3ms.

In order to run this application you will need Docker and executing the commands

./gradlew clean build

docker compose build

docker compose up

Here you can find a tutorial about Docker Compose.