Implement a Redis Cache Service in Java

Despina Papatheodorou
1 min readMay 15, 2022


What is Redis:
Redis is an open source , in-memory data structure store used as a database, cache, message broker, and streaming engine.
More info in

Jedis is a client library in Java for Redis

Install Redis
Check the instructions in

Java implementation

Add the Maven dependency in pom.xml


Create a new class JedisCacheService

private Jedis jedis; /**
* Initialize the cache (default: port 6379 , localhost)
* if you have started the service on a non-default port or a remote machine,
* you should configure it by passing the correct values as parameters into the constructor.*/
jedis = new Jedis();
/** expirationTimeinSeconds = timeout for the specified key. */ void set(String key, String value, int expirationTimeinSeconds) {
jedis.setex(key, expirationTimeinSeconds, value);
String get(String key) {String data = jedis.get(key); if (data != null)
return data;
return null;

Unit Test:

public void storeDataToRedisCache(){
int expirationTimeInSeconds = (int) TimeUnit.DAYS.toSeconds(30);
JedisCacheService jedisCacheService = new JedisCacheService();
String key = “key-1”;
String value = “value-1”;
jedisCacheService.set(key, value,expirationTimeInSeconds); String valueInCache = jedisCacheService.get(key);

Redis CLI

You can verify by checking from command line the data stored in Redis using the redis-cli

redis:6379> keys *
1) “key-1”
redis:6379> mget key-1
1) “value-1”

For more info for redis commands check the documentation
and for Jedis implemetation the

Code is also availible in
and the unit test in