When integrating textual data from relational databases into XML documents, developers freqeuntly encounter formatting conflicts. Raw strings often contain residual HTML markup and reserved characters that can break XML parsers. To resolve this, a two-step sanitization process is required: stripping markup elements and encapsulating the remaining text to prevent parser interference.

First, HTML tags must be removed. A compiled regular expression efficiently identifies and eliminatse opening and closing tags along with their attributes. Second, because the cleaned text may still contain characters like <, >, or &, wrapping the payload in a CDATA section ensures the XML processor treats the content as raw character data rather than executable markup.

import java.util.regex.Pattern;

public class XmlContentPreparator {

    private static final Pattern HTML_TAG_PATTERN = Pattern.compile("<[^>]+>");

    public static String preparePayload(String inputText) {
        if (inputText == null || inputText.trim().isEmpty()) {
            return inputText;
        }

        String strippedMarkup = HTML_TAG_PATTERN.matcher(inputText).replaceAll("");
        
        String normalizedText = strippedMarkup.replace("&nbsp;", " ").trim();

        return "<![CDATA[" + normalizedText + "]]>";
    }

    public static void main(String[] args) {
        String rawDatabaseString = "<p>Confidential data block 213131231231dvcxvxx rdc 123<sup>12</sup><sup><span style=\"text-decoration: underline;>123</span></sup><span style=\"text-decoration: none;><em>22</em>&lt;script&gt;alert(1)&lt;/script&gt;<strong>qwer</strong></span></p><p><span style=\"text-decoration: underline;><strong>hjdsjjfsdjkfkjdskf.&nbsp;</strong></span></p>";

        String processedString = preparePayload(rawDatabaseString);
        System.out.println(processedString);
    }
}

Executing the utility yields a sanitized string ready for safe insertion:

<![CDATA[Confidential data block 213131231231dvcxvxx rdc 1231212322<script>alert(1)</script>qwerhjdsjjfsdjkfkjdskf.]]>

This processed payload can now be embedded directly within XML elements without triggering validasion errors or parsing exceptions:

<books>
    <book>
        <author>Li Gang</author>
        <title>Advanced XML Processing</title>
        <publisher>Publishing House of Electronics Industry</publisher>
    </book>
    <book>
        <author>System Export</author>
        <title>Raw Data Extract</title>
        <description>
            <![CDATA[Confidential data block 213131231231dvcxvxx rdc 1231212322<script>alert(1)</script>qwerhjdsjjfsdjkfkjdskf.]]>
        </description>
    </book>
</books>