RedissonClient is throwing StringIndexOutOfBoundsException: begin 8, end 5, length 22 - redis

Question

I have below code for Redis Configuration, i need to use RedissonClient to flush cache after regular intervals.Using timerTask to run flush code. CacheManager and Proxy Manager is used because it is connected to bucket4j Ratelimiting code.
Connection to Docker Redis Image is successful as well. Using redisson version 3.12.5.
Following this doc: https://www.freecodecamp.org/news/rate-limiting-with-bucket4j-and-redis/
import io.github.bucket4j.distributed.proxy.ProxyManager;
import io.github.bucket4j.grid.jcache.JCacheProxyManager;
import java.util.Iterator;
import java.util.Timer;
import java.util.TimerTask;
import javax.cache.CacheManager;
import javax.cache.Caching;
import javax.cache.spi.CachingProvider;
import lombok.extern.log4j.Log4j2;
import org.ehcache.jsr107.EhcacheCachingProvider;
import org.redisson.Redisson;
import org.redisson.api.RedissonClient;
import org.redisson.config.Config;
import org.redisson.jcache.configuration.RedissonConfiguration;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.testcontainers.containers.GenericContainer;
import org.testcontainers.utility.DockerImageName;
import static java.util.concurrent.TimeUnit.MINUTES;
import static java.util.concurrent.TimeUnit.SECONDS;
#Log4j2
#Configuration
public class RedisConfig {
private static GenericContainer redis = null;
private RedissonClient redisson;
private final Timer timer = new Timer("RedisConfig", true);
private final CleanupRedis clean = new CleanupRedis(this);
public RedisConfig(){
timer.scheduleAtFixedRate(clean, SECONDS.toMillis(2), MINUTES.toMillis(2));
}
#Bean(name = "client")
public RedissonClient client() {
Config config = new Config();
if (redis == null) {
redis = new GenericContainer<>(redisImageName()).withExposedPorts(6379);
redis.start();
}
System.setProperty("spring.redis.host", redis.getHost());
System.setProperty("spring.redis.port", redis.getMappedPort(6379).toString());
config
.useSingleServer()
.setAddress("redis://" + redis.getHost() + redis.getMappedPort(6379));
RedissonClient rdson = Redisson.create(config);
return rdson;
}
#Bean
public CacheManager cacheManager(#Qualifier("client") RedissonClient redissonClient) {
Iterator<CachingProvider> iterator =
Caching.getCachingProviders(Caching.getDefaultClassLoader()).iterator();
while (iterator.hasNext()) {
CachingProvider provider = iterator.next();
if (!(provider instanceof EhcacheCachingProvider)) {
iterator.remove();
}
}
CacheManager manager = Caching.getCachingProvider().getCacheManager();
manager.createCache("cache", RedissonConfiguration.fromConfig(redissonClient.getConfig()));
return manager;
}
private static DockerImageName redisImageName() {
return DockerImageName.parse("docker.io/redis:5.0.3-alpine")
.asCompatibleSubstituteFor("redis:5.0.3-alpine");
}
#Bean
ProxyManager<String> proxyManager(CacheManager cacheManager) {
return new JCacheProxyManager<>(cacheManager.getCache("cache"));
}
protected class CleanupRedis extends TimerTask {
private RedisConfig redisConfig;
CleanupRedis(RedisConfig redisConfig) {
this.redisConfig = redisConfig;
}
#Override
public void run() {
try {
System.out.println("Redisson client call is being made");
RedissonClient redisson = Redisson.create(client().getConfig());
System.out.println("Redisson client is not working");
redisson.getKeys().flushdb();
log.debug("Successfully cleared the Redis Cache");
redisson.shutdown();
} catch (Exception e) {
log.debug("caught exception cleanup availability: {}", e.getMessage());
}
}
}
}