Java Utililty Methods XML Document Save to File

File output = new File(documentFileName);
StreamResult resultFile = new StreamResult(output);
DOMSource source = new DOMSource(node);
try {
    Transformer t = TransformerFactory.newInstance().newTransformer();
    t.setOutputProperty(OutputKeys.INDENT, "yes");
    t.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
    t.setOutputProperty(OutputKeys.METHOD, "xml");
...

DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();
DOMImplementationLS impl = (DOMImplementationLS) registry.getDOMImplementation("LS");
LSSerializer writer = impl.createLSSerializer();
String str = writer.writeToString(document);
str = str.replace("UTF-16", "UTF-8");
File outputFolder = new File(folderName);
outputFolder.mkdirs();
String fileName = outputFolder.getAbsolutePath() + "/" + "file_" + String.valueOf(index) + ".xml";
...

Transformer serializer = TransformerFactory.newInstance().newTransformer();
serializer.transform(new DOMSource(doc), new StreamResult(out));

Writer writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(f), "utf-8"));
try {
    int n = indent ? 4 : 0;
    writeByDom(doc, writer, n);
} finally {
    writer.close();

Source source = new DOMSource(document);
File file = new File(filename);
Result result = new StreamResult(file);
Transformer xformer = TransformerFactory.newInstance().newTransformer();
xformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
xformer.setOutputProperty(OutputKeys.INDENT, "yes");
xformer.transform(source, result);
return file;
...

TransformerFactory factory = TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
StreamResult result = new StreamResult(os);
DOMSource source = new DOMSource(doc);
transformer.transform(source, result);

TransformerFactory factory = TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
StringWriter sw = new StringWriter();
StreamResult result = new StreamResult(sw);
DOMSource source = new DOMSource(doc);
transformer.transform(source, result);
String xmlString = sw.toString();
...

System.setProperty(DOMImplementationRegistry.PROPERTY, "org.apache.xerces.dom.DOMImplementationSourceImpl");
DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();
DOMImplementation domImpl = registry.getDOMImplementation("LS 3.0");
DOMImplementationLS implLS = (DOMImplementationLS) domImpl;
LSSerializer dom3Writer = implLS.createLSSerializer();
LSOutput output = implLS.createLSOutput();
output.setByteStream(outputStreamXML);
output.setEncoding("UTF-8");
...

try {
    Transformer transformer = TransformerFactory.newInstance().newTransformer();
    DOMSource source = new DOMSource(doc);
    StreamResult result = new StreamResult(new OutputStreamWriter(new FileOutputStream(outfile), "UTF-8"));
    if (indent) {
        XPathFactory xpathFactory = XPathFactory.newInstance();
        XPathExpression xpathExp = xpathFactory.newXPath().compile("//text()[normalize-space(.) = '']");
        NodeList emptyTextNodes = (NodeList) xpathExp.evaluate(doc, XPathConstants.NODESET);
...

try {
    TransformerFactory tf = TransformerFactory.newInstance();
    Transformer transformer = tf.newTransformer();
    DOMSource source = new DOMSource(doc);
    transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8");
    PrintWriter pw = new PrintWriter(new FileOutputStream(filename));
    StreamResult result = new StreamResult(pw);
    transformer.transform(source, result);
...