Code:
String userid, password;
...
SHA1Digest sha1 = new SHA1Digest();
sha1.update(userid.getBytes(), 0, userid.length());
byte[] userHash = new byte[sha1.getBlockLength()];
sha1.getDigest(userHash, 0, true);
sha1.update(password.getBytes(), 0, password.length());
byte[] passHash = new byte[sha1.getBlockLength()];
sha1.getDigest(passHash, 0, true);