public static String unescape(String src)
    {
        StringBuffer tmp = new StringBuffer();
        tmp.ensureCapacity(src.length());
        int lastPos = 0,pos = 0;
        char ch;
        while(lastPos < src.length())
        {
            pos = src.indexOf("%",lastPos);
            if(pos == lastPos)
            {
                if(src.charAt(pos + 1) == 'u')
                {
                    ch = (char) Integer.parseInt(src.substring(pos + 2,pos + 6),16);
                    tmp.append(ch);
                    lastPos = pos + 6;
                }
                else
                {
                    ch = (char) Integer.parseInt(src.substring(pos + 1,pos + 3),16);
                    tmp.
                        append(ch);
                    lastPos = pos + 3;
                }
            }
            else
            {
                if(pos == -1)
                {
                    tmp.append(src.substring(lastPos));
                    lastPos = src.length();
                }
                else
                {
                    tmp.append(src.substring(lastPos,pos));
                    lastPos = pos;
                }
            }
        }
        return tmp.toString();
    }
    public static String escape(String src)
    {
        int i;
        char j;
        StringBuffer tmp = new StringBuffer();
        tmp.ensureCapacity(src.length() * 6);
        for(i = 0;i < src.length();i++)
        {
            j = src.charAt(i);
            if(Character.isDigit(j) || Character.isLowerCase(j) || Character.isUpperCase(j))
            {
                tmp.append(j);
            }
            else if(j < 256)
            {
                tmp.append("%");
                if(j < 16)
                {
                    tmp.append("0");
                }
                tmp.append(Integer.toString(j,16));
            }
            else
            {
                tmp.append("%u");
                tmp.append(Integer.toString(j,16));
            }
        }
        return tmp.toString();
    }