package com.demo;


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.Transformer;
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.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;


public class JavaXml
{
    public static void main(String argv[])
    {
        try
        {
            String filepath = "file.xml";
            DocumentBuilderFactory docFactory = DocumentBuilderFactory
                    .newInstance();
            DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
            Document doc = docBuilder.parse(filepath);

            Node staff = doc.getElementsByTagName("staff").item(0);

            // 更新属性值
            NamedNodeMap attr = staff.getAttributes();
            Node nodeAttr = attr.getNamedItem("id");
            nodeAttr.setTextContent("2");

            // 添加一个新的节点
            Element age = doc.createElement("age");
            age.appendChild(doc.createTextNode("28"));
            staff.appendChild(age);

            // 循环子类
            NodeList list = staff.getChildNodes();

            for (int i = 0; i < list.getLength(); i++)
            {

                Node node = list.item(i);

                if ("salary".equals(node.getNodeName()))
                {
                    node.setTextContent("20000");
                }

                if ("firstname".equals(node.getNodeName()))
                {
                    staff.removeChild(node);
                }

            }

            // 写入xml
            TransformerFactory transformerFactory = TransformerFactory
                    .newInstance();
            Transformer transformer = transformerFactory.newTransformer();
            DOMSource source = new DOMSource(doc);
            StreamResult result = new StreamResult(new File(filepath));
            transformer.transform(source, result);

        }
        catch (ParserConfigurationException pce)
        {
            pce.printStackTrace();
        }
        catch (TransformerException tfe)
        {
            tfe.printStackTrace();
        }
        catch (IOException ioe)
        {
            ioe.printStackTrace();
        }
        catch (SAXException sae)
        {
            sae.printStackTrace();
        }
    }
}