Deprecate redundant ByteUtils.extractBytes(…) method.

Refactors extractBytes(:ByteBuffer) to call getBytes(:ByteBuffer), thereby avoid the NullPointerException by throwing the more appropriate IllegalArgumentException with a descriptive message instead.

See #2733

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

@@ -376,16 +376,16 @@ public class RedisCacheConfiguration {
 	}
 
 	/**
-	 * Returns a computed {@link Duration TTL expiration timeout} based on cache entry key/value
+	 * Returns a computed {@link Duration TTL expiration timeout} based on cache entry key/value if a {@link TtlFunction}
-	 * if a {@link TtlFunction} was confiugred using {@link #entryTtl(TtlFunction)}.
+	 * was confiugred using {@link #entryTtl(TtlFunction)}.
 	 * <p>
-	 * Otherwise, returns the user-provided, fixed {@link Duration} if {@link #entryTtl(Duration)}
+	 * Otherwise, returns the user-provided, fixed {@link Duration} if {@link #entryTtl(Duration)} was called during cache
-	 * was called during cache configuration.
+	 * configuration.
 	 *
 	 * @return the configured {@link Duration TTL expiration}.
-	 * @deprecated since 3.2.0. Use {@link #getTtlFunction()} instead.
+	 * @deprecated since 3.2. Use {@link #getTtlFunction()} instead.
 	 */
-	@Deprecated(since = "3.2.0")
+	@Deprecated(since = "3.2")
 	public Duration getTtl() {
 		return getTtlFunction().getTimeToLive(Object.class, null);
 	}

src/main/java/org/springframework/data/redis/serializer/DefaultRedisElementReader.java

@@ -43,7 +43,7 @@ class DefaultRedisElementReader<T> implements RedisElementReader<T> {
 			return (T) buffer;
 		}
 
-		return serializer.deserialize(ByteUtils.extractBytes(buffer));
+		return serializer.deserialize(ByteUtils.getBytes(buffer));
 	}
 
 }

src/main/java/org/springframework/data/redis/util/ByteUtils.java

@@ -31,6 +31,7 @@ import org.springframework.util.ObjectUtils;
  * @author Christoph Strobl
  * @author Mark Paluch
  * @author Guy Korland
+ * @author John Blum
  * @since 1.7
  */
 public final class ByteUtils {
@@ -251,13 +252,10 @@ public final class ByteUtils {
 	 * @param buffer must not be {@literal null}.
 	 * @return the extracted bytes.
 	 * @since 2.1
+	 * @deprecated Since 3.2. Use {@link #getBytes(ByteBuffer)} instead.
 	 */
+	@Deprecated(since = "3.2")
 	public static byte[] extractBytes(ByteBuffer buffer) {
-
+		return getBytes(buffer);
-		ByteBuffer duplicate = buffer.duplicate();
-		byte[] bytes = new byte[duplicate.remaining()];
-		duplicate.get(bytes);
-
-		return bytes;
 	}
 }