domconvert2.java

用java对于xml文件的读取

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

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

import javax.xml.transform.TransformerFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.*;
import org.xml.sax.SAXException;

public class DOMConvert2
{
    public static void main(String[] args)
    {
        DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
        try
        {
            DocumentBuilder db=dbf.newDocumentBuilder();
            Document doc=db.parse("students.xml");
            
            Element eltStu=doc.createElement("student");
            Element eltName=doc.createElement("name");
            Element eltAge=doc.createElement("age");
            
            Attr attr=doc.createAttribute("sn");
            attr.setValue("03");
            
            Text txtName=doc.createTextNode("王五");
            Text txtAge=doc.createTextNode("19");
           
            eltName.appendChild(txtName); 
            eltAge.appendChild(txtAge);
            
            eltStu.appendChild(eltName);
            eltStu.appendChild(eltAge);
            
            eltStu.setAttributeNode(attr);
            
            Element eltRoot=doc.getDocumentElement();
            
            eltRoot.appendChild(eltStu);
            
            NodeList nl=doc.getElementsByTagName("student");
            
            Node nodeDel=(Element)nl.item(0);
            nodeDel.getParentNode().removeChild(nodeDel);
            
            Element eltChg=(Element)nl.item(0);
            Node nodeAgeChg=eltChg.getElementsByTagName("age").item(0);
            nodeAgeChg.getFirstChild().setNodeValue("22");
            
            //利用文档节点创建一个DOM输入源
            DOMSource source=new DOMSource(doc);
            //以converted.xml文件构造一个StreamResult对象，用于保存转换后结果。
            StreamResult result=new StreamResult(new File("converted.xml"));
            
            //得到转换器工厂类的实例
            TransformerFactory tff = TransformerFactory.newInstance();
            //创建一个新的转换器，用于执行恒等转换，
            //即直接将DOM输入源的内容复制到结果文档中。
            Transformer tf = tff.newTransformer();
            //执行转换
            tf.transform(source, result);

        }
        catch(ParserConfigurationException e){e.printStackTrace();}
        catch(SAXException e){e.printStackTrace();}
        catch(IOException e){e.printStackTrace();}
        catch(TransformerConfigurationException e){e.printStackTrace();}
        catch(TransformerException e){e.printStackTrace();}
    }
}