domconvert.java

孙鑫JAVA从入门到精通配套练习程序。所有程序都实际运行过

//演示XML文档数据的处理(增加，删除节点、修改数据)
import java.io.*;
import javax.xml.parsers.*;
import org.w3c.dom.*;
import org.xml.sax.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;

class DOMConvert
{
	public static void main(String[] args)
	{
		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
		try
		{
			DocumentBuilder db = dbf.newDocumentBuilder();
			Document doc = db.parse(new File("students.xml"));
			//----添加元素节点
			//创建元素节点
			Element eleStu = doc.createElement("student");
			Element eleName = doc.createElement("name");
			Element eleAge = doc.createElement("age");
			
			//创建文本节点
			Text txtName = doc.createTextNode("王五");
			Text txtAge = doc.createTextNode("19");
			
			//将节点添加到其父节点中,形成节点树
			eleName.appendChild(txtName);
			eleAge.appendChild(txtAge);
			eleStu.appendChild(eleName);
			eleStu.appendChild(eleAge);
			//设置元素节点的属性
			eleStu.setAttribute("sn","03");
			//将整个新创建的节点添加到根节点中
			Element root = doc.getDocumentElement();
			root.appendChild(eleStu);
			
			//----删除元素节点
			NodeList nl = root.getElementsByTagName("student");
			root.removeChild(nl.item(0));
			
			//----修改节点的值
			Element eleStuChg = (Element)nl.item(0);
			Node nodeAgeChg = eleStuChg.getElementsByTagName("age").item(0);
			nodeAgeChg.getFirstChild().setNodeValue("32");
			
			//打印输出节点信息
			int len = nl.getLength();
			for(int i=0; i<len; i++)
			{
				Element elt = (Element)nl.item(i);
				System.out.println("编号: " + elt.getAttribute("sn"));
				
				Node nodeName = elt.getElementsByTagName("name").item(0);
				Node nodeAge = elt.getElementsByTagName("age").item(0);
				
				String strName = nodeName.getFirstChild().getNodeValue();
				String strAge = nodeAge.getFirstChild().getNodeValue();
				
				System.out.println("姓名: " + strName);
				System.out.println("年龄: " + strAge);
				System.out.println("-------------------");
			}
			
			//将处理结果输出到另一个XML文档
			TransformerFactory tff = TransformerFactory.newInstance();
			Transformer tf = tff.newTransformer();
			tf.setOutputProperty("encoding","gb2312");
			DOMSource source = new DOMSource(doc);
			StreamResult result = new StreamResult(new File("converted.xml"));
			tf.transform(source,result);
			
		}
		catch(Throwable ex)
		{
			ex.printStackTrace();
		}
	}
}