static private String unicodeEncode(String word) {
        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < word.length(); ++i) {
            char ch = word.charAt(i);
            if (ch >= '\u0080') {
                String st = Integer.toHexString(0x10000 + (int) ch);
                while (st.length() < 4) st = "0" + st;
                buf.append("\\u").append(st.subSequence(1, 5));
            } else {
                buf.append(ch);
            }
        }
        return buf.toString();
    }