[HADOOP-7322] Adding a util method in FileUtil for JDK File.listFiles

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.23.0
• Release Note: Use of this new utility method avoids null result from File.listFiles(), and consequent NPEs.
• Assignee: Bharath Mundlapudi
• Reporter: Bharath Mundlapudi
• Created: 23/May/11 21:56
• Updated: 02/May/13 02:29
• Resolved: 25/May/11 21:55

Description

While testing Disk Fail Inplace, we encountered lots of NPE from Dir.listFiles API. This API can return null when Dir is not directory or disk is bad. I am proposing to have a File Util which can be used consistently across to deal with disk issues. This util api will do the following:

1. When error happens it will throw IOException
2. Else it will return empty list or list of files.

Signature:
File[] FileUtil.listFiles(File dir) throws IOException {}

This way we no need to write wrapper code every where. Also, API is consistent with the signature.

Issue Links

• blocks: HDFS-1934 Fix NullPointerException when File.listFiles() API returns null
• is depended upon by: HDFS-2023 Backport of NPE for File.list and File.listFiles
• is related to: HDFS-2137 Datanode Disk Fail Inplace