public static boolean directoryContains(File directory, File child) throws IOException {
if (directory == null) {
throw new IllegalArgumentException("Directory must not be null");
}
if (!directory.isDirectory()) {
throw new IllegalArgumentException("Not a directory: " + directory);
}
if (child == null) {
return false;
}
if ((!directory.exists()) || (!child.exists())) {
return false;
}
String canonicalParent = directory.getCanonicalPath();
String canonicalChild = child.getCanonicalPath();
return FilenameUtils.directoryContains(canonicalParent, canonicalChild);
}
