public static String encode(String s) 
{
        // Guess a bit bigger for encoded form
        StringBuilder buf = new StringBuilder(s.length() + 16);
        for (int i = 0; i <  s.length(); i++) {
            char ch = s.charAt(i);
            if ((ch  >= 'a' && ch < = 'z') || (ch  >= 'A' && ch < = 'Z')
                    || (ch  >= '0' && ch < = '9') || ".-*_".indexOf(ch)  > -1) { //$NON-NLS-1$
                buf.append(ch);
            } else if (ch == ' ') {
                buf.append('+');
            } else {
                byte[] bytes = new String(new char[] { ch }).getBytes();
                for (int j = 0; j <  bytes.length; j++) {
                    buf.append('%');
                    buf.append(digits.charAt((bytes[j] & 0xf0)  > > 4));
                    buf.append(digits.charAt(bytes[j] & 0xf));
                }
            }
        }
        return buf.toString();
}

Encodes a given string {@code s} in a x-www-form-urlencoded string using the specified encoding scheme {@code enc}.

All characters except letters ('a'..'z', 'A'..'Z') and numbers ('0'..'9') and characters '.', '-', '*', '_' are converted into their hexadecimal value prepended by '%'. For example: '#' -> %23. In addition, spaces are substituted by '+'

 public static String encode(String s,
    String enc) throws UnsupportedEncodingException 
{
        if (s == null || enc == null) {
            throw new NullPointerException();
        }
        // check for UnsupportedEncodingException
        "".getBytes(enc); //$NON-NLS-1$
        // Guess a bit bigger for encoded form
        StringBuffer buf = new StringBuffer(s.length() + 16);
        int start = -1;
        for (int i = 0; i <  s.length(); i++) {
            char ch = s.charAt(i);
            if ((ch  >= 'a' && ch < = 'z') || (ch  >= 'A' && ch < = 'Z')
                    || (ch  >= '0' && ch < = '9') || " .-*_".indexOf(ch)  > -1) { //$NON-NLS-1$
                if (start  >= 0) {
                    convert(s.substring(start, i), buf, enc);
                    start = -1;
                }
                if (ch != ' ') {
                    buf.append(ch);
                } else {
                    buf.append('+');
                }
            } else {
                if (start <  0) {
                    start = i;
                }
            }
        }
        if (start  >= 0) {
            convert(s.substring(start, s.length()), buf, enc);
        }
        return buf.toString();
}

Encodes the given string {@code s} in a x-www-form-urlencoded string using the specified encoding scheme {@code enc}.

All characters except letters ('a'..'z', 'A'..'Z') and numbers ('0'..'9') and characters '.', '-', '*', '_' are converted into their hexadecimal value prepended by '%'. For example: '#' -> %23. In addition, spaces are substituted by '+'