DOM生成XML文档与解析XML文档(JUNIT测试)

package cn.liuning.test;

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.Result;
import javax.xml.transform.Source;
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.junit.Test;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class Demo1
{
    
    @Test//dom生成XML文档
    public void createdXmlbyDom() throws ParserConfigurationException, TransformerException
    {
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();  
         DocumentBuilder builder = factory.newDocumentBuilder(); 
         Document document = builder.newDocument();
         //加入根结点
         Element rootElement = document.createElement("xml");  
         //新建子结点
         Element toUserName = document.createElement("ToUserName"); 
         //设置属性
         toUserName.setAttribute("id", "id_1");
         //设置内容
         String str = "<![CDATA[gh_1c586f95bd68]]>"; 
         toUserName.setTextContent(str);
         Element fromUserName = document.createElement("FromUserName");
         fromUserName.setAttribute("id", "id_2");
         String str1 = "<![CDATA[ogNtkuMTj4uOx-DCvLfu8mUDmubM]]>"; 
         fromUserName.setTextContent(str1);

         Element createTime = document.createElement("CreateTime");
         createTime.setAttribute("id", "id_2");
         String str2 = "1403313142"; 
         createTime.setTextContent(str2);
         
         Element createTime1 = document.createElement("CreateTime");
         createTime1.setAttribute("id", "id_2");
         String str3 = "Test"; 
         createTime1.setTextContent(str3);
         
         rootElement.appendChild(toUserName);
         rootElement.appendChild(fromUserName);
         rootElement.appendChild(createTime);
         rootElement.appendChild(createTime1);
         
         document.appendChild(rootElement); 
         
         TransformerFactory transformerFactory = TransformerFactory.newInstance();
         Transformer transformer = transformerFactory.newTransformer();
         Source xmlSource = new DOMSource(document);

         Result outputTarget = new StreamResult(new File("src/book1.xml"));  
         transformer.transform(xmlSource, outputTarget);
         System.out.println("成功");
    }
    @Test//dom解析XML文档
    public void read() throws ParserConfigurationException, Exception, IOException
    {
        //1.新建工厂        
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        //2.得到dom解析器
        DocumentBuilder builder = factory.newDocumentBuilder();
        //3.得到代表文档的document上
        Document document =  builder.parse("src/book1.xml");    

        System.out.println(document.getInputEncoding());//得到文档编码
    
        //通过标签名获取标签，得到的是一个list集合
        //NodeList list = document.getElementsByTagName("CreateTime");
        NodeList list = document.getElementsByTagName("xml");
        
        //常用方法
        System.out.println(list.getLength());//可以输出list的长度
        Node node = list.item(0); //得到第几个结点
        
        //node方法
        System.out.println(node.getNodeName());//得到结点名称，输出CreateTime
        System.out.println(node.hasAttributes());//是否有属性，输出true
        System.out.println(node.hasChildNodes());//是否有孩子，输出true
        String content = node.getTextContent();//获取结点内容
        System.out.println(content);

    }
}