How to Remove XML Declaration from Generated XML Document in Java

How can I eliminate the XML declaration from an XML document generated in Java?

// Example Java code related to XML generation.

When generating XML documents in Java, the default behavior of many libraries (like `javax.xml`) includes adding the XML declaration at the top of the document. This can be problematic when an XML declaration is not desired. Here’s how to remove it effectively.

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;

// Example method to generate XML without declaration
public void generateXMLWithoutDeclaration() throws Exception {
    DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
    Document doc = docBuilder.newDocument();

    // Create your XML structure here...

    TransformerFactory transformerFactory = TransformerFactory.newInstance();
    Transformer transformer = transformerFactory.newTransformer();
    transformer.setOutputProperty("omit-xml-declaration", "yes");
    DOMSource source = new DOMSource(doc);
    StreamResult result = new StreamResult(System.out); // Change according to your needs
    transformer.transform(source, result);
}

Causes

• The XML declaration is automatically included by the XML writer classes such as `Transformer` or `DocumentBuilder`.

Solutions

• Use `Transformer` to set properties that exclude the declaration.
• Use `StringWriter` with a custom output stream to write the XML without the declaration.

Mistake: Not setting the transformer output property correctly.

Solution: Ensure you use `transformer.setOutputProperty("omit-xml-declaration", "yes");` to omit the declaration.

Mistake: Overlooking character encoding settings while transforming.

Solution: Set the character encoding correctly using `setOutputProperty(TransformerFactory.KEY_ENCODING, "UTF-8");`.