XML解析

XML解析

xml

<?xml version="1.0" encoding="utf-8" standalone="no"?><class>

    <stu 地址="北京" 学号="a02" 性别="男">
        <name>sss</name>
        <age>18</age>
        <sex>男</sex>
    </stu>
<stu><name>王五</name><age>16</age><sex>男</sex></stu></class>

解析代码

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.util.List;

/** * Created by 宋贤 on 2015/10/13. */
public class DocumentXml {
    public static void main(String[] args) throws Exception{
        //创建一个DocumentBuilderFactory对象
        DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
        //通过DocumentBuilderFactory得到一个DocumentBuilder对象
        DocumentBuilder documentBuilder=dbf.newDocumentBuilder();
        //指定解析那个文件
        Document document=documentBuilder.parse("src/xml1.xml");
//        System.out.println(document);
//        list(document);
//        read(document);
//        add(document);
//        delete(document);
        update(document);
    }
    //遍历document
    public static void list(Node node){
         if(node.getNodeType()== node.ELEMENT_NODE) {
            System.out.println("名字+"+node.getNodeName());
        }
        //取出node的子节点
        NodeList nodeList=node.getChildNodes();
        for (int i=0;i<nodeList.getLength();i++){
            Node n=nodeList.item(i);
            list(n);
        }
    }
    public static void read(Document document){
        NodeList n=document.getElementsByTagName("stu");
//        System.out.println("发现+"+n.getLength()+"学生");
        Element stu1=(Element)n.item(0);
        System.out.println("学号是+"+stu1.getAttribute("学号"));
        Element name=(Element)stu1.getElementsByTagName("age").item(0);
        System.out.println(name.getTextContent());
    }
    //添加学生
    public static void add(Document document) throws Exception {
        //创建一个新的学生节点
        Element nstu=document.createElement("stu");
        Element nstu_name=document.createElement("name");
        nstu_name.setTextContent("王五");
        Element nstu_age=document.createElement("age");
        nstu_age.setTextContent("16");
        Element nstu_sex=document.createElement("sex");
        nstu_sex.setTextContent("男");
        nstu.appendChild(nstu_name);
        nstu.appendChild(nstu_age);
        nstu.appendChild(nstu_sex);
        //把新的学生节点添加到根元素下
        document.getDocumentElement().appendChild(nstu);
        //更新文档
        TransformerFactory transformerFactory=TransformerFactory.newInstance();
        Transformer tf=transformerFactory.newTransformer();
        tf.transform(new DOMSource(document), new StreamResult("src/xml1.xml"));
    }
    public static void delete(Document document) throws Exception{
//        Node node=document.getElementsByTagName("stu").item(0);
//        node.getParentNode().removeChild(node);
        Element element=(Element)document.getElementsByTagName("stu").item(0);
        element.removeAttribute("大哥");
        //更新文档
        TransformerFactory transformerFactory=TransformerFactory.newInstance();
        Transformer tf=transformerFactory.newTransformer();
        tf.transform(new DOMSource(document), new StreamResult("src/xml1.xml"));
    }
    public static void update(Document document) throws Exception{
        Element element=(Element)document.getElementsByTagName("stu").item(0);
        Element element1=(Element)element.getElementsByTagName("name").item(0);
        element1.setTextContent("sss");
        TransformerFactory transformerFactory=TransformerFactory.newInstance();
        Transformer tf=transformerFactory.newTransformer();
        tf.transform(new DOMSource(document), new StreamResult("src/xml1.xml"));
     }
}