DOM解析示例

Posted 2020-08-18 三碗才能饱

收藏信息.xml

<?xml version="1.0" encoding="GB2312" standalone="no"?><PhoneInfo>
    <Brand id="0" name="华为">
        <Type name="U8650"/>
        <Type name="HW123"/>
        <Type name="HW321"/>
    </Brand>
    <Brand id="1" name="苹果">
        <Type name="iPhone4"/>
    </Brand>
<Brand id="2" name="三星"><type name="s120"/></Brand></PhoneInfo>

解析示例：

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
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.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;


public class ParseXml {
    private Document document;
    //获取DOM树
    public void getDom(){
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder;
            try {
                builder = factory.newDocumentBuilder();
                document = builder.parse("收藏信息.xml");
            } catch (ParserConfigurationException e) {
                e.printStackTrace();
            } catch (SAXException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
    }
    
    //遍历XML信息
    public void showInfo(){
        NodeList nodes = document.getElementsByTagName("Brand");
        for(int i=0;i<nodes.getLength();i++){
            Node node = nodes.item(i);
            Element ele = (Element)node;
            String brandName = ele.getAttribute("name");
            System.out.println(brandName);
            
            NodeList types = ele.getChildNodes();
            for(int j=0;j<types.getLength();j++){
                Node typeNode = types.item(j);
                //如果节点是元素节点时再类型转换
                if(typeNode.getNodeType() == Node.ELEMENT_NODE){
                    Element typeEle = (Element)typeNode;
                    String typeName = typeEle.getAttribute("name");
                    System.out.println(typeName);
                }
            }
        
        }
        
    }
    
    //保存XML
    public void saveXml(String path){
        TransformerFactory factory = TransformerFactory.newInstance();
        try {
            //获取解析器
            Transformer transformer = factory.newTransformer();
            //指定特定的输出格式
            transformer.setOutputProperty(OutputKeys.ENCODING, "GB2312");
            //源
            DOMSource source = new DOMSource(document);
            //目标
            StreamResult result = new StreamResult(new FileOutputStream(path));
            //解析
            transformer.transform(source, result);
            
        } catch (TransformerConfigurationException e) {
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (TransformerException e) {
            e.printStackTrace();
        }
        
    }
    
    
    //向XML添加节点
    public void addEle(){
        Element Brand = document.createElement("Brand");
        Brand.setAttribute("name", "三星");
        Element type = document.createElement("type");
        type.setAttribute("name", "s120");
        Brand.appendChild(type);
        document.getElementsByTagName("PhoneInfo").item(0).appendChild(Brand);
        saveXml("收藏信息.xml");
    }
    
    //修改XML元素，为每个Brand节点添加一个ID属性，分别为0,1，2
    public void updateEle(){
        NodeList brand = document.getElementsByTagName("Brand");
        for(int i=0;i<brand.getLength();i++){
            Node node = brand.item(i);
            Element ele = (Element)node;
            ele.setAttribute("id", i+"");
        }
        saveXml("收藏信息.xml");
    }
    
    
    //删除手机品牌为华为的相关元素
    public void deleteEle(){
        NodeList brand = document.getElementsByTagName("Brand");
        for(int i=0;i<brand.getLength();i++){
            Node node = brand.item(i);
            Element brandEle = (Element)node;
            if(brandEle.getAttribute("name").equals("华为")){
                brandEle.getParentNode().removeChild(brandEle);
            }
        }
        saveXml("收藏信息.xml");
    }
    
    
    
    
    
    public static void main(String[] args) {
        ParseXml px = new ParseXml();
        px.getDom();
        px.showInfo();
//        px.saveXml("wjb.xml");
//        px.addEle();    
        px.updateEle();    
        px.deleteEle();
    }
    
    
    
    
}