private String[] toFilePaths(final List<String> urls) {
final List<String> files = new ArrayList<String>();
for (String url : urls) {
final File dir = new File(url);
if (!dir.isDirectory()) {
continue;
}
for (File f : Files.collect(dir, new ClassFilter())) {
files.add(f.getAbsolutePath());
}
}
return files.toArray(new String[files.size()]);
}
public static String hash(final Set<URL> urls, final String algo) {
final Collection<File> files = new ArrayList<File>();
for (final URL u : urls) {
final File file = toFile(u);
if (!file.isDirectory()) {
files.add(file);
} else {
files.addAll(Files.collect(file, TrueFilter.INSTANCE));
}
}
MessageDigest digest = DIGESTS.get(algo);
if (digest == null) {
try {
digest = MessageDigest.getInstance(algo);
} catch (final NoSuchAlgorithmException e) {
throw new LoaderRuntimeException(e);
}
DIGESTS.put(algo, digest);
}
for (final File file : files) {
if (!file.exists()) {
continue;
}
DigestInputStream is = null;
try {
is = new DigestInputStream(new FileInputStream(file), digest);
IO.copy(is, new NoopOutputStream()); // read the stream
} catch (final IOException e) {
// no-op: shouldn't occur here
} finally {
IO.close(is);
}
}
final byte[] hash = digest.digest();
digest.reset();
final StringBuilder sb = new StringBuilder("");
for (final byte b : hash) { // hex convertion
sb.append(Integer.toString((b & 0xff) + 0x100, 16).substring(1));
}
return sb.toString();
}