XMLItem - strip invalid non UTF-8 characters

[rsoika]

It can happen that not UTF-8 compliant characters occur in a String Object. (for example if users pastes mixed text content into a text field)

This results in a JAX-B marshaling process to an invalid XML output. As a result the XML output can not be further processed!

To avoid this, we need a routine that filters out such characters.

I found a solution in Mark McLaren's Weblog: http://blog.mark-mclaren.info/2007/02/invalid-xml-characters-when-valid-utf8_5873.html

This is a code example form Mark McLaren

/**
     * This method ensures that the output String has only
     * valid XML unicode characters as specified by the
     * XML 1.0 standard. For reference, please see
     * <a href="http://www.w3.org/TR/2000/REC-xml-20001006#NT-Char">the
     * standard</a>. This method will return an empty
     * String if the input is null or empty.
     *
     * @param in The String whose non-valid characters we want to remove.
     * @return The in String, stripped of non-valid 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); // NOTE: No IndexOutOfBoundsException caught here; it should not happen.
            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();
    }