[doc] fix java client javadoc typo
@@ -264,10 +264,10 @@ public interface Message<T> {
Optional<Long> getBrokerPublishTime();
/**
- * Check whether the message has a index.
+ * Check whether the message has an index.
*
* @since 2.9.0
- * @return true if the message has a index, otherwise false.
+ * @return true if the message has an index, otherwise false.
*/
boolean hasIndex();
