FileFilter() accepts if File.isDirectory()

[Jon Camilleri]

Why does the code snippet accept when f.isDirectory() == true, since it intends to select files ending with ".xml"?

...
// accept all files ending with .xml
      chooser.setFileFilter(new javax.swing.filechooser.FileFilter()
         {
            public boolean accept(File f)
            {
               return f.getName().toLowerCase().endsWith(".xml") || f.isDirectory();
            }

            public String getDescription()
            {
               return "XML files";
            }
         });
...

Source Core Java Vol I (8th Ed) Listing 10-7. P.541

[Stephan van Hulst]

Because you want the file chooser to display folders as well, since you want to be able to browse through directory structures.

[Rob Spoor]

Without the "|| f.isDirectory()" part you will see only XML files in the current folder. No other files, but also no sub folders. That makes it hard to navigate. The JFileChooser will make sure that it will not allow actual selection of directories if you've set its mode correctly (by default it allows only selection of files so that's usually good already).