views:

480

answers:

2

I am trying to figure out how to use apache commons io DirectoryWalker. It's pretty easy to understand how to subclass DirectoryWalker. But how do you start executing it on a particular directory?

+3  A: 

It looks like the subclass should provide a public method that calls walk().

Duck
argh!!! of course, how the @#$@#$@# did I miss seeing that?
Jason S
don't you hate it when that happens >.<
Nippysaurus
actually it looks like you don't have to provide a method that calls walk. another class can call walk() from the outside.
Jason S
d'oh! I stand corrected, walk() is protected. you are 100% right!
Jason S
+4  A: 

Just to expand on this answer since I was puzzled at first of how to use the class as well and this question came up on google when I was looking around. This is just an example of how I used it (minus some things):

public class FindConfigFilesDirectoryWalker extends DirectoryWalker {
    private static String rootFolder = "/xml_files";
    private Logger log = Logger.getLogger(getClass());

    private static IOFileFilter filter = FileFilterUtils.andFileFilter(FileFilterUtils.fileFileFilter(),
      FileFilterUtils.suffixFileFilter("xml"));

    public FeedFileDirectoryWalker() {
     super(filter, -1);
    }

    @SuppressWarnings("unchecked")
    @Override
    protected void handleFile(final File file, final int depth, final Collection results) throws IOException {
     log.debug("Found file: " + file.getAbsolutePath());
     results.add(file);
    }

    public List<File> getFiles() {
     List<File> files = new ArrayList<File>();

     URL url = getClass().getResource(rootFolder);

     if (url == null) {
      log.warn("Unable to find root folder of configuration files!");
      return files;
     }

     File directory = new File(url.getFile());

     try {
      walk(directory, files);
     }
     catch (IOException e) {
      log.error("Problem finding configuration files!", e);
     }

     return files;
    }
}

And then you would just invoke it via the public method you created, passing in any arguments that you may want:

List<File> files = new FindConfigFilesDirectoryWalker().getFiles();
rcl