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>