Remove unnecessary usages of Optional.

Signed-off-by: facewise <dydguskim@gripcorp.co>
Closes #3203

Author: facewise

src/main/java/org/springframework/data/redis/cache/BatchStrategies.java

@@ -16,11 +16,10 @@
 package org.springframework.data.redis.cache;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.NoSuchElementException;
-import java.util.Optional;
+import java.util.Set;
 
 import org.springframework.data.redis.connection.RedisConnection;
 import org.springframework.data.redis.core.Cursor;
@@ -33,6 +32,7 @@
  * @author Mark Paluch
  * @author Christoph Strobl
  * @author John Blum
+ * @author Yong-Hyun Kim
  * @since 2.6
  */
 public abstract class BatchStrategies {
@@ -79,14 +79,17 @@ static class Keys implements BatchStrategy {
 		@Override
 		public long cleanCache(RedisConnection connection, String name, byte[] pattern) {
 
-			byte[][] keys = Optional.ofNullable(connection.keys(pattern)).orElse(Collections.emptySet())
-					.toArray(new byte[0][]);
+			RedisKeyCommands commands = connection.keyCommands();
 
-			if (keys.length > 0) {
-				connection.del(keys);
-			}
+            Set<byte[]> keys = commands.keys(pattern);
+
+            if (keys == null || keys.isEmpty()) {
+                return 0;
+            }
+
+            commands.del(keys.toArray(new byte[0][]));
 
-			return keys.length;
+			return keys.size();
 		}
 	}
 

src/main/java/org/springframework/data/redis/connection/RedisPassword.java

@@ -34,6 +34,7 @@
  *
  * @author Mark Paluch
  * @author Christoph Strobl
+ * @author Yong-Hyun Kim
  * @since 2.0
  */
 public class RedisPassword {
@@ -54,10 +55,11 @@ private RedisPassword(char[] thePassword) {
 	 */
 	public static RedisPassword of(@Nullable String passwordAsString) {
 
-		return Optional.ofNullable(passwordAsString) //
-				.filter(StringUtils::hasText) //
-				.map(it -> new RedisPassword(it.toCharArray())) //
-				.orElseGet(RedisPassword::none);
+        if (!StringUtils.hasText(passwordAsString)) {
+            return none();
+        }
+
+        return new RedisPassword(passwordAsString.toCharArray());
 	}
 
 	/**
@@ -68,10 +70,11 @@ public static RedisPassword of(@Nullable String passwordAsString) {
 	 */
 	public static RedisPassword of(@Nullable char[] passwordAsChars) {
 
-		return Optional.ofNullable(passwordAsChars) //
-				.filter(it -> !ObjectUtils.isEmpty(passwordAsChars)) //
-				.map(it -> new RedisPassword(Arrays.copyOf(it, it.length))) //
-				.orElseGet(RedisPassword::none);
+        if (ObjectUtils.isEmpty(passwordAsChars)) {
+            return none();
+        }
+
+        return new RedisPassword(Arrays.copyOf(passwordAsChars, passwordAsChars.length));
 	}
 
 	/**