Recursive listFiles with filter

// Java's File class provides listFiles for listing all files in a directory but this does not recurse into subdirectories. This implementation does with an optional filter:

// NB: This uses Java5 features such as foreach loop and generics but these can be removed to work with Java4 (see comments)

public static File[] listFilesAsArray(
File directory,
FilenameFilter filter,
boolean recurse)
{
Collection<File> files = listFiles(directory,
filter, recurse);
// Java4: Collection files = listFiles(directory, filter, recurse);

File[] arr = new File[files.size()];
return files.toArray(arr);
}

public static Collection<File> listFiles(
// Java4: public static Collection listFiles(
File directory,
FilenameFilter filter,
boolean recurse)
{
// List of files / directories
Vector<File> files = new Vector<File>();
// Java4: Vector files = new Vector();

// Get files / directories in the directory
File[] entries = directory.listFiles();

// Go over entries
for (File entry : entries)
{
// Java4: for (int f = 0; f < files.length; f++) {
// Java4: File entry = (File) files[f];

// If there is no filter or the filter accepts the
// file / directory, add it to the list
if (filter == null filter.accept(directory, entry.getName()))
{
files.add(entry);
}

// If the file is a directory and the recurse flag
// is set, recurse into the directory
if (recurse && entry.isDirectory())
{
files.addAll(listFiles(entry, filter, recurse));
}
}

// Return collection of files
return files;
}