byte[] utf8 String unicode

    public static final String utf8_decode(byte[] utf8_bytes) throws java.io.UTFDataFormatException {
        return utf8_decode(utf8_bytes, 0, utf8_bytes.length);
    }

    public static final String utf8_decode(byte[] utf8_bytes, int start, int len) throws java.io.UTFDataFormatException {
        if (utf8_bytes == null)
            return null;
        int end = start + len;
        char[] unicode_chars = new char[len];
        int i, counter = 0;
        try {
            for (i = start; i < end; i++) {
                byte b = utf8_bytes[i];
                if ((b >> 7) == 0) { // read one byte
                    unicode_chars[counter++] = (char) (b);
                } else if ((b >> 5) == (byte) 0xfe) { // read two bytes
                    unicode_chars[counter] = (char) ((char) (b & 0x1f) << 6);
                    unicode_chars[counter++] += utf8_bytes[++i] & 0x3f;
                } else if ((b >> 4) == (byte) 0xfe) { // read three bytes
                    unicode_chars[counter] = (char) ((char) (b & 0xf) << 12);
                    unicode_chars[counter] += (char) ((char) (utf8_bytes[++i] & 0x3f) << 6);
                    unicode_chars[counter++] += utf8_bytes[++i] & 0x3f;
                }
            }
            return new String(unicode_chars, 0, counter);
        } catch (Exception ex) {
            throw new java.io.UTFDataFormatException();
        }
    }

    public static final byte[] utf8_encode(String src) {
        if (src == null)
            return null;
        /** copy chars into array */
        int len = src.length();
        char[] chars = src.toCharArray();
        byte[] bytes = new byte[len * 3];
        int counter = 0;
        char c;
        for (int n = 0; n < len; n++) {
            c = chars[n];
            if (c < 128)
                bytes[counter++] = (byte) c;
            else if ((c > 127) && (c < 2048)) {
                bytes[counter++] = (byte) ((c >> 6) | 192);
                bytes[counter++] = (byte) ((c & 63) | 128);
            } else {
                bytes[counter++] = (byte) ((c >> 12) | 224);
                bytes[counter++] = (byte) (((c >> 6) & 63) | 128);
                bytes[counter++] = (byte) ((c & 63) | 128);
            }
        }
        byte[] result = new byte[counter];
        System.arraycopy(bytes, 0, result, 0, counter);
        bytes = null;
        chars = null;
        return result;
    }