Add retryable command execution example (#3780)

Co-authored-by: ggivo <[email protected]>

Author: sazzad16

src/test/java/redis/clients/jedis/examples/RetryableCommandExecution.java

@@ -0,0 +1,45 @@
+package redis.clients.jedis.examples;
+
+import java.time.Duration;
+import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
+import redis.clients.jedis.Connection;
+import redis.clients.jedis.ConnectionPoolConfig;
+import redis.clients.jedis.DefaultJedisClientConfig;
+import redis.clients.jedis.HostAndPort;
+import redis.clients.jedis.JedisClientConfig;
+import redis.clients.jedis.UnifiedJedis;
+import redis.clients.jedis.providers.PooledConnectionProvider;
+
+/**
+ * It is possible to retry command executions in case of connection failures in UnifiedJedis class.
+ *
+ * The retry-ability comes through RetryableCommandExecutor class. It is also possible to directly provide
+ * RetryableCommandExecutor as a parameter.
+ *
+ * Note: RetryableCommandExecutor should not be considered for
+ * <a href="https://redis.io/docs/reference/cluster-spec/">Open Source Redis Cluster mode</a> because it requires to
+ * handle more than connection failures. These are done in ClusterCommandExecutor.
+ */
+public class RetryableCommandExecution {
+
+  public static void main(String[] args) {
+
+    // Connection and pool parameters
+    HostAndPort hostAndPort = new HostAndPort("127.0.0.1", 6379);
+    JedisClientConfig clientConfig = DefaultJedisClientConfig.builder().user("myuser").password("mypassword").build();
+    GenericObjectPoolConfig<Connection> poolConfig = new ConnectionPoolConfig();
+
+    PooledConnectionProvider provider = new PooledConnectionProvider(hostAndPort, clientConfig, poolConfig);
+
+    // Retry parameters
+    int maxAttempts = 5;
+    Duration maxTotalRetriesDuration = Duration.ofSeconds(2);
+
+    UnifiedJedis jedis = new UnifiedJedis(provider, maxAttempts, maxTotalRetriesDuration);
+
+    jedis.set("foo", "bar");
+    jedis.get("foo");
+
+    jedis.close();
+  }
+}