java实现XML增加元素操作简单示例

package Day01;import java.io.*;import javax.xml.parsers.*;import javax.xml.transform.*;import javax.xml.transform.dom.DOMSource;import javax.xml.transform.stream.StreamResult;import org.w3c.dom.*;public class CRUDDEMO {  /*public void addElement() throws Exception{    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();    DocumentBuilder builder = factory.newDocumentBuilder();    Document doc = builder.parse(new File ("src/Day01/Book.xml"));    Element newEle = doc.createElement("作者");    newEle.setTextContent("ZC");    Node nod = doc.getElementsByTagName("书").item(0);    nod.appendChild(newEle);    Source sour = new DOMSource(doc);    Result result = new StreamResult (new FileOutputStream("src/Day01/Book.xml"));    write (sour, result);  }*/  public void addElement2() throws Exception{    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); //建立工厂    DocumentBuilder builder = factory.newDocumentBuilder(); //拿到builder    Document doc = builder.parse(new File ("src/Day01/Book.xml")); //获得document，这是终极目的    Element newEle = doc.createElement("作者");// 创建新元素/标签    newEle.setTextContent("ZC"); //给元素设置内容 <作者>ZC</作者>    Node nod = doc.getElementsByTagName("书名").item(0); //通过nodelist的item()方法获得具体节点    /**     * 在具体节点插入元素用 节点.insertBefore方法     * 第一个参数是要插入的新节点，第二个是插入的位置     */    nod.insertBefore(newEle, doc.getElementsByTagName("书名").item(0));    /**     * DOMSource(Node n)     * 注意 element是Node的一个子类，所以可以把doc放入构造函数     *     *     */    Source sour = new DOMSource(doc);    Result result = new StreamResult (new FileOutputStream("src/Day01/Book.xml"));    write (sour, result);  }  public void write(Source source,Result result) {    TransformerFactory tffactory = TransformerFactory.newInstance();    Transformer tr;    try {      tr = tffactory.newTransformer();      tr.transform(source, result);    } catch (TransformerConfigurationException e) {      // TODO Auto-generated catch block      e.printStackTrace();    } catch (TransformerException e) {      // TODO Auto-generated catch block      e.printStackTrace();    }  }  public static void main(String[] args) throws Exception {    CRUDDEMO cr = new CRUDDEMO();    cr.addElement2();  }}

<?xml version="1.0" encoding="UTF-8" standalone="no"?><书架>  <书>    <书名>Thinking in Java</书名>    <作者>Eric</作者>    <售价>$34</售价>  </书></书架>

<?xml version="1.0" encoding="UTF-8" standalone="no"?><书架>  <书>    <作者>ZC</作者>    <书名>Thinking in Java</书名>    <作者>Eric</作者>    <售价>$34</售价>  </书></书架>