XML解析代码课堂讲解实例

    //获取所有的子元素，不包括回车

package com.dom4jDemo;

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

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

public class Dom4jDemo1 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        String path = "src/scores.xml";
        File file = new File(path);
        SAXReader saxReader = new SAXReader();
        try {
            Document doc = saxReader.read(file);
            Element root = doc.getRootElement();
            //获取所有的子元素，不包括回车
            List<Element> eles = root.elements();
            for(Element ele : eles){
                System.out.println(ele.getName());
                List<Element> children = ele.elements();
                for(Element e : children){
                    System.out.println(e.getName() + "\t" + e.getText());
                }
            }
        } catch (DocumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }   

}




DOM4j




``package com.dom4jDemo;

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

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class Dom4jDemo2 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        String path = "src/scores.xml";
        File file = new File(path);
        SAXReader saxReader = new SAXReader();
        try {
            Document doc = saxReader.read(file);
            //获取根元素
            Element root = doc.getRootElement();
            //获取一个指定名字的子元素
            Element eleStu = root.element("student");
            //复制节点
            Element newStu = (Element) eleStu.clone();
            //获取子元素并设置值
            newStu.element("id").setText("5");
            newStu.element("name").setText("孙七");
            newStu.element("lesson").setText("hibernate");
            newStu.element("score").setText("92");
            root.add(newStu);
            //删除节点
            root.remove(eleStu);
            //设置输出编码
            OutputFormat of = OutputFormat.createCompactFormat();
            of.setEncoding("GBK");
            //构建输出流对象
            XMLWriter xw 
            = new XMLWriter(new FileWriter(file),of);
            xw.write(doc);
            xw.close();
        } catch (DocumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

package com.dom;

import java.io.IOException;

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

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 DomDemo {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    //文件路径
    String path = "src/scores.xml";
    //创建解析器工厂
    DocumentBuilderFactory dbf 
     = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = null;
    try {//使用解析器工厂创建解析器
        db = dbf.newDocumentBuilder();
        //将XML文件映射成文档对象
        Document doc = db.parse(path);
        //根元素
        Element root = doc.getDocumentElement();
        System.out.println(root.getNodeName());
        //获取所有的子元素,包含换行和标签元素
        NodeList children = //root.getChildNodes();
                //获取标签名为student的元素集合，不包括换行
                root.getElementsByTagName("student");
        for(int i = 0; i < children.getLength();i++){
            Node node = children.item(i);
            //跳过换行

// if(node.getNodeType() == Node.TEXT_NODE){
// continue;
// }
System.out.println(node.getNodeName() + “\t” + node.getNodeValue());
Element ele = (Element)node;
//获取子元素的子元素
NodeList childNodes = ele.getChildNodes();
for(int j = 0;j < childNodes.getLength();j++){
Node n = childNodes.item(j);
if(n.getNodeType() == Node.TEXT_NODE){
continue;
}
System.out.println(n.getNodeName() + “\t” + n.getTextContent());
}
System.out.println(childNodes.getLength());
}
System.out.println(“子元素的数量：” + children.getLength());
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}

package com.dom;

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.xml.sax.SAXException;

public class DomDemo2 {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    String path = "src/scores.xml";
    DocumentBuilderFactory dbf 
     = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = null;
    try {
        db = dbf.newDocumentBuilder();
        Document doc = db.parse(path);
        Element root = doc.getDocumentElement();
        //第一种添加元素的办法

// Element eleStu = doc.createElement(“student”);
// Element eleId = doc.createElement(“id”);
// eleId.setTextContent(“3”);//设置文本值
// Element eleName = doc.createElement(“name”);
// eleName.setTextContent(“王五”);
// Element eleLesson = doc.createElement(“lesson”);
// eleLesson.setTextContent(“oracle”);
// Element eleScore = doc.createElement(“score”);
// eleScore.setTextContent(“78”);
// eleStu.appendChild(eleId);
// eleStu.appendChild(eleName);
// eleStu.appendChild(eleLesson);
// eleStu.appendChild(eleScore);
// root.appendChild(eleStu);//添加元素至根元素
//第二种添加元素的办法
//获取要添加的元素的模板，获取一个现有元素
Element eleStu = (Element) root.getElementsByTagName(“student”).item(0);
//复制现有元素创造一个新元素,包含换行
Element newEle = (Element) eleStu.cloneNode(true);
Node nodeId = newEle.getElementsByTagName(“id”).item(0);
nodeId.setTextContent(“4”);
Node nodeName = newEle.getElementsByTagName(“name”).item(0);
nodeName.setTextContent(“赵六”);
Node nodeLesson = newEle.getElementsByTagName(“lesson”).item(0);
nodeLesson.setTextContent(“JQuery”);
Node nodeScore = newEle.getElementsByTagName(“score”).item(0);
nodeScore.setTextContent(“88”);
root.appendChild(newEle);//添加元素至根元素
//保存文件
TransformerFactory tff =
TransformerFactory.newInstance();
Transformer tf = tff.newTransformer();
//设置要保存哪些内容到XML文件，默认是整个
DOMSource ds = new DOMSource(doc);
//设置保存编码
tf.setOutputProperty(OutputKeys.ENCODING, “UTF-8”);
StreamResult sr = new StreamResult(new FileOutputStream(path));
tf.transform(ds, sr);
System.out.println(“保存完成”);
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TransformerConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TransformerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}

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