[HBASE-17846] [JDK8] Use Optional instead of Nullable parameter in async client

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 2.0.0
• Assignee: Unassigned
• Reporter: Guanghao Zhang
• Created: 29/Mar/17 10:18
• Updated: 15/Jun/22 23:55
• Resolved: 27/Jun/17 09:56

Description

For master branch, we use a lot of java 8 features in async client, like lambda, stream, default method and so on. And java 8 support Optional, we can update some method to use Optional instead of Nullable parameter.