使用JAXP对XML文档进行DOM解析

 import java.io.FileOutputStream;

 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.transform.Transformer;
 import javax.xml.transform.TransformerFactory;
 import javax.xml.transform.dom.DOMSource;
 import javax.xml.transform.stream.StreamResult;

 import org.junit.Test;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;

 //使用dom方式对xml文档进行crud
 public class Demo2 {

     @Test
     public void read() throws Exception{

         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         DocumentBuilder builder = factory.newDocumentBuilder();
         Document document = builder.parse("src/book.xml");

         NodeList list = document.getElementsByTagName("书名");
         Node node = list.item(1);
         String content = node.getTextContent();
         System.out.println(content);

     }

     @Test
     public void read2() throws Exception{

         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         DocumentBuilder builder = factory.newDocumentBuilder();
         Document document = builder.parse("src/book.xml");

         //得到根节点
         Node root = document.getElementsByTagName("书架").item(0);
         list(root);
     }

     private void list(Node node) {
         if(node instanceof Element){
         System.out.println(node.getNodeName());
         }
         NodeList list = node.getChildNodes();

         for(int x=0;x<list.getLength()-1;x++){
             Node child = list.item(x);
             list(child);
             //System.out.println(child.getTextContent());
         }

     }

     //得到xml文档中标签属性值：<书名 name="xxxx">Java就业培训教程</书名>
     @Test
     public void read3() throws Exception{

         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         DocumentBuilder builder = factory.newDocumentBuilder();
         Document document = builder.parse("src/book.xml");

         //得到根节点
         Element bookname = (Element) document.getElementsByTagName("书名").item(0);
         String value = bookname.getAttribute("name");
         System.out.println(value);
     }

     //向xml文档中添加节点：<售价>59.00元</售价>
     @Test
     public void add() throws Exception{
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         DocumentBuilder builder = factory.newDocumentBuilder();
         Document document = builder.parse("src/book.xml");

         //创建节点
         Element price =document.createElement("售价");
         price.setTextContent("59.00元");

         //把创建的节点挂到第一本书上
         Element book = (Element) document.getElementsByTagName("书").item(0);
         book.appendChild(price);

         //把更新后内存写回xml中
         TransformerFactory tffactory = TransformerFactory.newInstance();
         Transformer tf = tffactory.newTransformer();
         tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/book.xml")));

     }

     //向xml文档中指定位置上添加节点：<售价>59.00元</售价>
     @Test
     public void add2() throws Exception{
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         DocumentBuilder builder = factory.newDocumentBuilder();
         Document document = builder.parse("src/book.xml");

         //创建节点
         Element price =document.createElement("售价");
         price.setTextContent("59.00元");

         //得到参考节点
         Element refNode = (Element) document.getElementsByTagName("作者").item(1);

         //得到要挂载的节点
         Element book = (Element) document.getElementsByTagName("书").item(1);

         //往book节点的指定位置插崽
         book.insertBefore(price, refNode);

         //把更新后内存写回xml中
         TransformerFactory tffactory = TransformerFactory.newInstance();
         Transformer tf = tffactory.newTransformer();
         tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/book.xml")));

     }

     //向xml文档节点上添加属性：<书名>java就业培训教程</书名>上添加name="zero"属性
     @Test
     public void addAttr() throws Exception{
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         DocumentBuilder builder = factory.newDocumentBuilder();
         Document document = builder.parse("src/book.xml");

         Element bookname = (Element) document.getElementsByTagName("书名").item(0);
         bookname.setAttribute("name", "zero");

         //把更新后内存写回xml中
         TransformerFactory tffactory = TransformerFactory.newInstance();
         Transformer tf = tffactory.newTransformer();
         tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/book.xml")));

     }

     @Test
     public void delete() throws Exception{
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         DocumentBuilder builder = factory.newDocumentBuilder();
         Document document = builder.parse("src/book.xml");

         //得到要删除节点
         Element e = (Element) document.getElementsByTagName("售价").item(1);
         System.out.println(e);
         //得到要删除的节点
         Element book = (Element) document.getElementsByTagName("书").item(1);
         System.out.println(book);
         //父节点删子节点
         book.removeChild(e);

         //把更新后内存写回xml中
         TransformerFactory tffactory = TransformerFactory.newInstance();
         Transformer tf = tffactory.newTransformer();
         tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/book.xml")));

     }

     //delete
     @Test
     public void delete2() throws Exception{
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         DocumentBuilder builder = factory.newDocumentBuilder();
         Document document = builder.parse("src/book.xml");

         //得到要删除节点
         Element e = (Element) document.getElementsByTagName("售价").item(1);
         e.getParentNode().getParentNode().removeChild(e.getParentNode());

         //把更新后内存写回xml中
         TransformerFactory tffactory = TransformerFactory.newInstance();
         Transformer tf = tffactory.newTransformer();
         tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/book.xml")));

     }

     //update
     @Test
     public void update() throws Exception{
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         DocumentBuilder builder = factory.newDocumentBuilder();
         Document document = builder.parse("src/book.xml");

         Element e = (Element) document.getElementsByTagName("售价").item(1);
         e.setTextContent("168元");

         //把更新后内存写回xml中
         TransformerFactory tffactory = TransformerFactory.newInstance();
         Transformer tf = tffactory.newTransformer();
         tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/book.xml")));

     }
 }

 <?xml version="1.0" encoding="UTF-8" standalone="no"?><书架>
     <书>
         <书名 name="zero">Java就业培训教程</书名>
         <售价>59.00元</售价>
         <作者>张孝祥</作者>
     </书>
     <书>
         <书名 name="zero">Java就业培训教程</书名>
         <售价>168元</售价>
         <作者>张孝祥</作者>
     </书>

 </书架>