import java.io.File;import java.io.FileOutputStream;import java.io.OutputStream;import java.util.List;import org.dom4j.Document;import org.dom4j.DocumentHelper;import org.dom4j.Element;import org.dom4j.io.OutputFormat;import org.dom4j.io.SAXReader;import org.dom4j.io.XMLWriter;//使用dom4j其它的APIpublic class Demo4 {    public static void main(String[] args) throws Exception {        //String->XML        String text = "<root><res>这是根元素</res></root>";        Document document = DocumentHelper.parseText(text);        OutputFormat format = OutputFormat.createPrettyPrint();        OutputStream os = new FileOutputStream("src/day2/domx/stringcar.xml");        XMLWriter xmlWriter = new XMLWriter(os,format);        xmlWriter.write(document);        xmlWriter.close();        /*创建空XML文件*/        Document document = DocumentHelper.createDocument();        document.addElement("root").setText("这是根元素");        OutputFormat format = OutputFormat.createPrettyPrint();        OutputStream os = new FileOutputStream("src/day2/domx/stringcar.xml");        XMLWriter xmlWriter = new XMLWriter(os,format);        xmlWriter.write(document);        xmlWriter.close();        /*指定插入次序，默认插入到最后*/        SAXReader saxReader = new SAXReader();        Document document = saxReader.read(new File("src/day2/domx/stringcar.xml"));        List<Element> elementList = document.getRootElement().elements();        Element newCarElement = DocumentHelper.createElement("汽车");        newCarElement.setText("这是我的汽车");        elementList.add(1,newCarElement);        OutputFormat format = OutputFormat.createPrettyPrint();        OutputStream os = new FileOutputStream("src/day2/domx/stringcar.xml");        XMLWriter xmlWriter = new XMLWriter(os,format);        xmlWriter.write(document);        xmlWriter.close();        //XML->String        SAXReader saxReader = new SAXReader();        Document document = saxReader.read(new File("src/day2/domx/stringcar.xml"));        Element rootElement = document.getRootElement();        Element firstCarElement = (Element) rootElement.elements().get(0);        String xml = firstCarElement.asXML();        System.out.println(xml);    }}