RediSolar for Java

Introduction

This is the sample application codebase for RU102J, Redis for Java Developers at Redis University.

Solutions to the course programming challenges can be found on the solutions branch.

Prerequisites

In order to start and run this application, you will need:

• Java 8 JDK or higher
• Maven
• Access to a local or remote installation of Redis version 5 or newer (local preferred, Docker is a good option - see instructions below)
• If you want to try the RedisTimeSeries exercises, you'll need to make sure that your Redis installation also has the RedisTimeSeries Module installed (or use the provided Docker Compose file which gives you Redis with RedisTimeSeries)
• Optional: Docker
• Optional but recommended: RedisInsight to visualize the data in Redis. This is a graphical alternative to the redis-cli command

If you're using Windows, check out the following resources for help with running Redis:

• Redis Blog - Running Redis on Windows 10
• Microsoft - Windows Subsystem for Linux Installation Guide for Windows 10

Running Redis with Docker

We've provided a Docker Compose file as part of this repo, so to start Redis with the RedisTimeSeries module installed, use the following command:

docker-compose up -d

This will start a Redis with RedisTimeSeries container on localhost port 6379 with no password and you should see output similar to the following:

Creating network "ru102j_default" with the default driver
Creating redis_ru102j ... done

Connect to Redis using either RedisInsight, or the redis-cli command. When using redis-cli you can invoke it from the Docker container like this:

docker exec -it redis_ru102j redis-cli

When you see this prompt:

127.0.0.1:6379>

you are connected to Redis. Type quit to exit the Redis CLI.

When you are finished working with Redis, shut down the server like so:

docker-compose down

Redis saves your data in an append only file in the redisdata folder, and will re-load it next time you start the container.

How to Start the RediSolar Application

Before anything else, start your redis server.

If having Redis installed in localhost:

$sudo service redis-server restart

When using Redis on localhost, port 6379 with no password:

1. Run mvn package to build your application.
2. Load the sample data: java -jar target/redisolar-1.0.jar load. If you want to erase everything in Redis before loading the data, use java -jar target/redisolar-1.0.jar load --flush true, but be aware that this will delete ALL keys in your Redis database. Note that loading the data may take a few minutes.
3. Start the application with java -jar target/redisolar-1.0.jar server config.yml
4. To check that your application is running enter url http://localhost:8081, substituting localhost for the hostname that you're running the application on if necessary.

When using Redis on another host, port or with a password:

1. Edit config.yml, setting the values for your Redis host, port and password if needed.
2. Edit src/test/java/com/redislabs/university/RU102J/HostPort.java, setting the values for your Redis host, port, and password if needed.
3. Run mvn package to build your application.
4. Load the sample data with java -jar target/redisolar-1.0.jar load --host <hostname> --port <port> --password <password>.
5. Start application with java -jar target/redisolar-1.0.jar server config.yml.
6. To check that your application is running enter url http://localhost:8081, substituting localhost for the hostname that you're running the application on if necessary.

Tests

To run all tests:

mvn test

To run a specific test:

mvn test -Dtest=JedisBasicsTest

Building

To rebuild the application:

mvn package

To rebuild the application without running the tests:

mvn package -DskipTests 

Need Help / Join our Community

If you need help with the course or want to chat to your fellow students and the wider Redis community, please join us on our Discord server.

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