Method to get rid off invalid XML characters:-

public String stripNonValidXMLCharacters(String in) {
        StringBuffer out = new StringBuffer(); // Used to hold the output.
        char current; // Used to reference the current character.

        if (in == null || ("".equals(in))) return ""; // vacancy test.
        for (int i = 0; i < in.length(); i++) {
            current = in.charAt(i); 
            if ((current == 0x9) ||
                (current == 0xA) ||
                (current == 0xD) ||
                ((current >= 0x20) && (current <= 0xD7FF)) ||
                ((current >= 0xE000) && (current <= 0xFFFD)) ||
                ((current >= 0x10000) && (current <= 0x10FFFF)))
                out.append(current);
        }
        return out.toString();
    }