xml ---DOM操作

package day03.xml;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import javax.xml.crypto.dsig.Transform;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
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.junit.Test;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

//使用dom方式对xml进行crud
public class Demo3 {
    @Test
    public void read() throws ParserConfigurationException, SAXException, IOException{
        DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
        DocumentBuilder builder=factory.newDocumentBuilder();
        Document document=(Document) builder.parse("src/2.xml");
        NodeList list=document.getElementsByTagName("soft");
        Node node = list.item(1);
        String content = node.getTextContent();
        System.out.println(content);
    }
    @Test
    public void read1() throws ParserConfigurationException, SAXException, IOException{
        DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
        DocumentBuilder builder=factory.newDocumentBuilder();
        Document document=builder.parse("src/2.xml");
        
        //获得根结点
        Node root=document.getElementsByTagName("soft").item(0);
        list(root);
    }
    private void list(Node node){
        if(node instanceof Element){
        System.out.println(node.getNodeName());
        }
        NodeList list=node.getChildNodes();
        for(int i=0;i<list.getLength();i++){
            Node child=list.item(i);
            list(child);
        }
    }
    @Test
    //得到name属性内容
    public void read3() throws ParserConfigurationException, SAXException, IOException{
        DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
        DocumentBuilder builder=factory.newDocumentBuilder();
        Document document=builder.parse("src/2.xml");
        Element bookname=(Element) document.getElementsByTagName("soft").item(0);
        String value =bookname.getAttribute("name");
        System.out.println(value);
        
    }
    @Test
    //向xml中添加节点<雪>22222<雪>
    public void add1() throws ParserConfigurationException, SAXException, IOException, TransformerException{
        DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
        DocumentBuilder builder=factory.newDocumentBuilder();
        Document document=builder.parse("src/2.xml");
        //创建节点
        Element price=document.createElement("雪");
        price.setTextContent("22222");

        //把创建的节点挂到第一本书上
        Element book=(Element) document.getElementsByTagName("a").item(0);
        book.appendChild(price);
        
        //把更新的内容重新写入xml文件里
        TransformerFactory transform =TransformerFactory.newInstance();
        Transformer tf=transform.newTransformer();
        tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/2.xml")));
        
    }
    @Test
    //向xml中添加节点在<a2>22222</a2>前
    public void add2() throws ParserConfigurationException, SAXException, IOException, TransformerException{
        DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
        DocumentBuilder builder=factory.newDocumentBuilder();
        Document document=builder.parse("src/2.xml");
        //创建节点
        Element price=document.createElement("a3");
        price.setTextContent("a222222before");

        //参考节点
        Element renode=(Element) document.getElementsByTagName("a2").item(0);
        //得到要挂的节点
        Element book=(Element) document.getElementsByTagName("a").item(0);    
        //往book节点的制定位置插入
        book.insertBefore(price,renode);
        //把更新的内容重新写入xml文件里
        TransformerFactory transform =TransformerFactory.newInstance();
        Transformer tf=transform.newTransformer();
        tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/2.xml")));
        
    }
    @Test
    //向xml中<a2>22222</a2>节点添加name属性=“xxxxx”
    public void add3() throws ParserConfigurationException, SAXException, IOException, TransformerException{
        DocumentBuilderFactory factory=DocumentBuilderFactory.newInstance();
        DocumentBuilder builder=factory.newDocumentBuilder();
        Document document=builder.parse("src/2.xml");
        
        //取得节点
        Element bookname =(Element) document.getElementsByTagName("a2").item(0);
        bookname.setAttribute("name","XXXXXX");
        
        //把更新的内容重新写入xml文件里
        TransformerFactory transform =TransformerFactory.newInstance();
        Transformer tf=transform.newTransformer();
        tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/2.xml")));
        
    }

}

<?xml version="1.0" encoding="UTF-8" standalone="no"?><soft name="snowing">
    <a>
        <a1>中国</a1>
        <a3>a222222before</a3>
        <a2 name="XXXXXX">ssssss</a2>
        <雪>22222</雪>
    </a>
    <b>
        <b1/>
        <b2/>
        <雪莹>879</雪莹>
    </b>
</soft>