[HDFS-13193] Various Improvements for BlockTokenSecretManager

• Type: Improvement
• Status: Resolved
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 3.0.0
• Fix Version/s: 3.1.0
• Component/s: hdfs
• Hadoop Flags: Reviewed
• Assignee: David Mollitor
• Reporter: David Mollitor
• Created: 24/Feb/18 21:15
• Updated: 19/Mar/18 18:31
• Resolved: 27/Feb/18 16:48

Description

Various improvements for class org.apache.hadoop.hdfs.security.token.block.BlockTokenSecretManager.java

1. Remove superfluous toString calls
2. Fix some checkstyle warnings
3. Re-implement method with O(N^2) with HashMultiSet - also improves readability
4. Increase code re-use with Apache Commons Library