////////////////////////////////////////////////////////////////////////////

要操作的xml文件

<?xml version="1.0" encoding="GB2312" standalone="no"?><PhoneInfo>
    <Brand name="华为">
        <Type name="U8650"/><Type name="HW123"/>
        <Type name="HW321"/>
    </Brand>
    <Brand name="苹果">
    <Type name="iPhone4"/>
    </Brand>
    <Brand name="vivo">
        <Type name="nb"/>
    </Brand>
</PhoneInfo>

//////////////////////////////////////////////////////////////////////////////////////////////////

package xinhuiji_day15;

import java.io.File;
import java.io.IOException;

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

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class xmlTest {

    /**
     * @param args
     * @throws ParserConfigurationException
     * @throws IOException
     * @throws SAXException
     * @throws TransformerException
     */
    public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException, TransformerException {
//        test3();
//        findId("3");
        addNode();
    }
　　//查找节点的内容
    public static void test3() throws ParserConfigurationException,
            SAXException, IOException {
        DocumentBuilderFactory daoFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = daoFactory.newDocumentBuilder();
        Document doc = builder.parse("src/网易手机各地行情.xml");
        NodeList nodeList = doc.getElementsByTagName("pubDate");
        for(int i = 0;i<nodeList.getLength();i++){
            Element e = (Element) nodeList.item(i);
            System.out.println(e.getFirstChild().getNodeValue());
        }
    }
    
    public void test() throws ParserConfigurationException, SAXException, IOException{
        DocumentBuilderFactory daoFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = daoFactory.newDocumentBuilder();
        Document doc = builder.parse("src/收藏信息.xml");
        NodeList nodeList = doc.getElementsByTagName("Brand");
        for(int i = 0;i<nodeList.getLength();i++){
            Element e = (Element) nodeList.item(i);
//            System.out.println(e.getFirstChild().getNodeValue());
            System.out.println(e.getTagName());
            System.out.println(e.getAttribute("name"));
            NodeList nod = e.getElementsByTagName("Type");
            for(int j = 0;j<nod.getLength();j++){
                Element ne = (Element) nod.item(j);
                System.out.println("\t"+ne.getAttribute("name"));
            }
        }
    }
    
    public static void findId(String id) throws ParserConfigurationException, SAXException, IOException{
        DocumentBuilderFactory daoFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = daoFactory.newDocumentBuilder();
        Document doc = builder.parse("src/网易手机各地行情.xml");
        NodeList nodeList = doc.getElementsByTagName("item");
        for(int i = 0;i<nodeList.getLength();i++){
            Element e = (Element) nodeList.item(i);
            String xmlId = e.getAttribute("id");
            if(xmlId.equals(id)){
                System.out.println(e.getElementsByTagName("title").item(0)
                        .getFirstChild().getNodeValue());
            }
        }
    }
    //增加节点
    public static void addNode() throws ParserConfigurationException, SAXException, IOException, TransformerException{
        DocumentBuilderFactory daoFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = daoFactory.newDocumentBuilder();
        Document doc = builder.parse("src/收藏信息.xml");
        Element brandElement = doc.createElement("Brand");
        brandElement.setAttribute("name", "vivo");
        Element typeElement = doc.createElement("Type");
        typeElement.setAttribute("name", "nb");
        Element rootElement = (Element) doc.getElementsByTagName("PhoneInfo").item(0);
        brandElement.appendChild(typeElement);
        rootElement.appendChild(brandElement);
        //向xml文件中写
        TransformerFactory tff = TransformerFactory.newInstance();
        Transformer ts = tff.newTransformer();
        DOMSource source = new DOMSource(doc);
        ts.setOutputProperty(OutputKeys.ENCODING, "gb2312");
        StreamResult result = new StreamResult(new File("src/收藏信息.xml"));
        ts.transform(source, result);
        
        
    }

}