首先得到：得到 DOM 解析器的工厂实例      DocumentBuilderFactory domfac=DocumentBuilderFactory.newInstance();

然后从 DOM 工厂获得 DOM 解析器

 DocumentBuilder dombuilder=domfac.newDocumentBuilder();

）把要解析的 XML 文档转化为输入流，以便 DOM 解析器解析它

InputStream is= new  FileInputStream("test1.xml");        

（ 4 ）解析 XML 文档的输入流，得到一个 Document

 Document doc=dombuilder.parse(is);

（ 5 ）得到 XML 文档的根节点

Element root=doc.getDocumentElement();

（ 6 ）得到节点的子节点

  NodeList books=root.getChildNodes();
代码如下：

package com.st.demo;  

import java.io.File;  
import java.io.FileInputStream;  
import java.io.InputStream;  

import javax.xml.parsers.DocumentBuilder;  
import javax.xml.parsers.DocumentBuilderFactory;  

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

public class XmlReader {  
    public static void main(String[] args) {  
        XmlReader reader = new XmlReader();  
    }  
    public XmlReader(){  
        DocumentBuilderFactory domfac = DocumentBuilderFactory.newInstance();  
        try {  
            DocumentBuilder domBuilder = domfac.newDocumentBuilder();  
            InputStream is = new FileInputStream(new File("D:/test1.xml"));  
            Document doc = domBuilder.parse(is);  
            Element root = doc.getDocumentElement();  
            NodeList books = root.getChildNodes();  
            if(books!=null){  
                for (int i = 0; i < books.getLength(); i++) {  
                    Node book = books.item(i);  
                     if(book.getNodeType()==Node.ELEMENT_NODE) {  
                            //（7）取得节点的属性值  
                            String email=book.getAttributes().getNamedItem("email").getNodeValue();  
                            System.out.println(email);  
                            //注意，节点的属性也是它的子节点。它的节点类型也是Node.ELEMENT_NODE  
                            //（8）轮循子节点  
                            for(Node node=book.getFirstChild();node!=null;node=node.getNextSibling()) {  
                                if(node.getNodeType()==Node.ELEMENT_NODE) {  
                                    if(node.getNodeName().equals("name")) {  
                                        String name=node.getNodeValue();  
                                        String name1=node.getFirstChild().getNodeValue();  
                                        System.out.println(name);  
                                        System.out.println(name1);  
                                    }  
                                    if(node.getNodeName().equals("price")) {  
                                        String price=node.getFirstChild().getNodeValue();  
                                        System.out.println(price);  
                                    }  
                                }  
                            }  
                     }  
                }  
            }  
        } catch (Exception e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
        }  

    }  
}