[HADOOP-18029] Update CompressionCodecFactory to handle uppercase file extensions

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 3.4.0
• Component/s: common, io, test
• Labels: pull-request-available

Environment

Tested locally on macOS 11.6.1, IntelliJ IDEA 2021.2.3, running maven commands through terminal. Forked from trunk branch on November 29th, 2021.

• Hadoop Flags: Reviewed
• External issue URL: https://github.com/apache/hadoop/pull/3739
• Assignee: Desmond Sisson
• Reporter: Desmond Sisson
• Created: 01/Dec/21 00:11
• Updated: 14/Dec/21 21:44
• Resolved: 02/Dec/21 00:53

Description

I've updated the CompressionCodecFactory to be able to handle filenames with capitalized compression extensions. Two of the three maps internal to the class which are used to store codecs have existing lowercase casts, but it is absent from the call inside getCodec() used for comparing path names.

I updated the corresponding unit test in TestCodecFactory to include intended use cases, and confirmed the test passes with the change. I also updated the error message in the case of a null from an NPE to a rich error message. I've resolved all checkstyle violations within the changed files.

Issue Links

• links to: GitHub Pull Request #3739