使用dom4j其它的API

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API
public 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);
	}
}