diff --git a/src/main/java/org/springframework/data/redis/connection/ClusterCommandExecutor.java b/src/main/java/org/springframework/data/redis/connection/ClusterCommandExecutor.java
index 5f2f8146e..194c831ef 100644
--- a/src/main/java/org/springframework/data/redis/connection/ClusterCommandExecutor.java
+++ b/src/main/java/org/springframework/data/redis/connection/ClusterCommandExecutor.java
@@ -152,8 +152,8 @@ public class ClusterCommandExecutor implements DisposableBean {
 	/**
 	 * Lookup node from the topology.
 	 *
-	 * @param node
-	 * @return
+	 * @param node must not be {@literal null}.
+	 * @return never {@literal null}.
 	 * @throws IllegalArgumentException in case the node could not be resolved to a topology-known node
 	 */
 	private RedisClusterNode lookupNode(RedisClusterNode node) {
@@ -167,8 +167,8 @@ public class ClusterCommandExecutor implements DisposableBean {
 	/**
 	 * Run {@link ClusterCommandCallback} on all reachable master nodes.
 	 *
-	 * @param cmd
-	 * @return
+	 * @param cmd must not be {@literal null}.
+	 * @return never {@literal null}.
 	 * @throws ClusterCommandExecutionFailureException
 	 */
 	public <S, T> MultiNodeResult<T> executeCommandOnAllNodes(final ClusterCommandCallback<S, T> cmd) {
@@ -176,9 +176,9 @@ public class ClusterCommandExecutor implements DisposableBean {
 	}
 
 	/**
-	 * @param callback
-	 * @param nodes
-	 * @return
+	 * @param callback must not be {@literal null}.
+	 * @param nodes must not be {@literal null}.
+	 * @return never {@literal null}.
 	 * @throws ClusterCommandExecutionFailureException
 	 * @throws IllegalArgumentException in case the node could not be resolved to a topology-known node
 	 */
@@ -263,8 +263,8 @@ public class ClusterCommandExecutor implements DisposableBean {
 	/**
 	 * Run {@link MultiKeyClusterCommandCallback} with on a curated set of nodes serving one or more keys.
 	 *
-	 * @param cmd
-	 * @return
+	 * @param cmd must not be {@literal null}.
+	 * @return never {@literal null}.
 	 * @throws ClusterCommandExecutionFailureException
 	 */
 	public <S, T> MultiNodeResult<T> executeMultiKeyCommand(MultiKeyClusterCommandCallback<S, T> cmd,
@@ -390,7 +390,7 @@ public class ClusterCommandExecutor implements DisposableBean {
 		private RedisClusterNode node;
 		private Object[] args;
 
-		public NodeExecution(RedisClusterNode node, Object... args) {
+		NodeExecution(RedisClusterNode node, Object... args) {
 
 			this.node = node;
 			this.args = args;
@@ -399,7 +399,7 @@ public class ClusterCommandExecutor implements DisposableBean {
 		/**
 		 * Get the {@link RedisClusterNode} the execution happens on.
 		 */
-		public RedisClusterNode getNode() {
+		RedisClusterNode getNode() {
 			return node;
 		}
 
@@ -556,7 +556,7 @@ public class ClusterCommandExecutor implements DisposableBean {
 		}
 
 		/**
-		 * @param returnValue
+		 * @param returnValue can be {@literal null}.
 		 * @return
 		 */
 		public T getFirstNonNullNotEmptyOrDefault(T returnValue) {
diff --git a/src/main/java/org/springframework/data/redis/connection/ClusterTopology.java b/src/main/java/org/springframework/data/redis/connection/ClusterTopology.java
index 92cf61c93..be689a997 100644
--- a/src/main/java/org/springframework/data/redis/connection/ClusterTopology.java
+++ b/src/main/java/org/springframework/data/redis/connection/ClusterTopology.java
@@ -40,7 +40,7 @@ public class ClusterTopology {
 	 * @param nodes can be {@literal null}.
 	 */
 	public ClusterTopology(Set<RedisClusterNode> nodes) {
-		this.nodes = nodes != null ? nodes : Collections.<RedisClusterNode> emptySet();
+		this.nodes = nodes != null ? nodes : Collections.emptySet();
 	}
 
 	/**
@@ -123,7 +123,7 @@ public class ClusterTopology {
 	 * Get the {@link RedisClusterNode} that is the current master serving the given key.
 	 *
 	 * @param key must not be {@literal null}.
-	 * @return
+	 * @return never {@literal null}.
 	 * @throws ClusterStateFailureException
 	 */
 	public RedisClusterNode getKeyServingMasterNode(byte[] key) {
@@ -131,13 +131,15 @@ public class ClusterTopology {
 		Assert.notNull(key, "Key for node lookup must not be null!");
 
 		int slot = ClusterSlotHashUtil.calculateSlot(key);
+
 		for (RedisClusterNode node : nodes) {
 			if (node.isMaster() && node.servesSlot(slot)) {
 				return node;
 			}
 		}
-		throw new ClusterStateFailureException(String.format("Could not find master node serving slot %s for key '%s',",
-				slot, key));
+
+		throw new ClusterStateFailureException(
+				String.format("Could not find master node serving slot %s for key '%s',", slot, key));
 	}
 
 	/**
@@ -145,7 +147,7 @@ public class ClusterTopology {
 	 *
 	 * @param host must not be {@literal null}.
 	 * @param port
-	 * @return
+	 * @return never {@literal null}.
 	 * @throws ClusterStateFailureException
 	 */
 	public RedisClusterNode lookup(String host, int port) {
@@ -155,15 +157,16 @@ public class ClusterTopology {
 				return node;
 			}
 		}
-		throw new ClusterStateFailureException(String.format(
-				"Could not find node at %s:%s. Is your cluster info up to date?", host, port));
+
+		throw new ClusterStateFailureException(
+				String.format("Could not find node at %s:%s. Is your cluster info up to date?", host, port));
 	}
 
 	/**
 	 * Get the {@link RedisClusterNode} matching given {@literal nodeId}.
 	 *
 	 * @param nodeId must not be {@literal null}.
-	 * @return
+	 * @return never {@literal null}.
 	 * @throws ClusterStateFailureException
 	 */
 	public RedisClusterNode lookup(String nodeId) {
@@ -175,23 +178,24 @@ public class ClusterTopology {
 				return node;
 			}
 		}
-		throw new ClusterStateFailureException(String.format(
-				"Could not find node at %s. Is your cluster info up to date?", nodeId));
+
+		throw new ClusterStateFailureException(
+				String.format("Could not find node at %s. Is your cluster info up to date?", nodeId));
 	}
 
 	/**
-	 * Get the {@link RedisClusterNode} matching matching either {@link RedisClusterNode#getHost() host} and {@link RedisClusterNode#getPort() port}
-	 * or {@link RedisClusterNode#getId() nodeId}
+	 * Get the {@link RedisClusterNode} matching matching either {@link RedisClusterNode#getHost() host} and
+	 * {@link RedisClusterNode#getPort() port} or {@link RedisClusterNode#getId() nodeId}
 	 *
 	 * @param node must not be {@literal null}
-	 * @return
- 	 * @throws ClusterStateFailureException
+	 * @return never {@literal null}.
+	 * @throws ClusterStateFailureException
 	 */
 	public RedisClusterNode lookup(RedisClusterNode node) {
 
 		Assert.notNull(node, "RedisClusterNode must not be null!");
 
-		if(nodes.contains(node) && StringUtils.hasText(node.getHost()) && StringUtils.hasText(node.getId())){
+		if (nodes.contains(node) && StringUtils.hasText(node.getHost()) && StringUtils.hasText(node.getId())) {
 			return node;
 		}
 
diff --git a/src/main/java/org/springframework/data/redis/connection/jedis/JedisZSetCommands.java b/src/main/java/org/springframework/data/redis/connection/jedis/JedisZSetCommands.java
index 8fe879a54..38cb617a4 100644
--- a/src/main/java/org/springframework/data/redis/connection/jedis/JedisZSetCommands.java
+++ b/src/main/java/org/springframework/data/redis/connection/jedis/JedisZSetCommands.java
@@ -38,7 +38,7 @@ class JedisZSetCommands implements RedisZSetCommands {
 
 	private final JedisConnection connection;
 
-	public JedisZSetCommands(JedisConnection connection) {
+	JedisZSetCommands(JedisConnection connection) {
 		this.connection = connection;
 	}