[FLINK-8473] JarListHandler may fail with NPE if directory is deleted

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.4.0, 1.5.0
• Fix Version/s: 1.5.0, 1.4.1
• Component/s: Webfrontend
• Assignee: Chesnay Schepler
• Reporter: Chesnay Schepler
• Created: 22/Jan/18 12:12
• Updated: 24/Jan/18 12:32
• Resolved: 24/Jan/18 12:32

Description

The JarListHandler is responsible for listing all jars that have been uploaded via the webUI. Uploaded jars are stored in a temporary directory, and the handler simply iterates over the contents of this directory to create the listing.

 

File[] list = jarDir.listFiles(new FilenameFilter() {
   @Override
   public boolean accept(File dir, String name) {
      return name.endsWith(".jar");
   }
});

// last modified ascending order
Arrays.sort(list, (f1, f2) -> Long.compare(f2.lastModified(), f1.lastModified()));

This code will fail with a NullPointerException if the directory was deleted (like as part of some automatic cleanup). File#listFiles returns null in this case causing Arrays.sort to throw the NPE.

Issue Links

• links to: GitHub Pull Request #5331