When saving an XML file in Java, multiple runs show that after each run, a line of white space is added between the elements, and the most recently inserted data is normal. How to solve this problem?

public class OperateXml {
    public static void main(String[] args) {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        try {
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document document = builder.parse("src/main/resources/chunkInfo/chunk.xml");
            add(document);
            saveDocument(document, new File("src/main/resources/chunkInfo/chunk.xml"));
        } catch (Exception e) {

        }
    }

    public static void saveDocument(Document document, File xmlFile) {
        TransformerFactory tff = TransformerFactory.newInstance();
        tff.setAttribute("indent-number", 2);
        try {
            Transformer tf = tff.newTransformer();
            tf.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, "chunk.dtd");
            tf.setOutputProperty(OutputKeys.INDENT, "yes");
            tf.transform(new DOMSource(document), new StreamResult(xmlFile));
        } catch (TransformerConfigurationException e) {
            e.printStackTrace();
        } catch (TransformerException e) {
            e.printStackTrace();
        }
    }

    public static void add(Document document) {
        Element root = document.getDocumentElement();
        Element chunk = document.createElement("chunk");
        root.appendChild(chunk);
        chunk.setAttribute("id", "id_8");
        Element name = document.createElement("name");
        name.setTextContent("test_6");
        chunk.appendChild(name);
        Element type = document.createElement("type");
        type.setTextContent("log");
        chunk.appendChild(type);
        Element item = document.createElement("item");
        item.setTextContent("2,3,4,5");
        chunk.appendChild(item);
    }
}

The result of saving XML file is:

CodePudding user response：

May be it's a result of a known bug in Java9 or later.

For further details see: https://bugs.openjdk.org/browse/JDK-8262285?attachmentViewMode=list