Xml解析

 Xml解析需要依赖 Dom4j包 备注：记得导入Dom4j包

XML的作用

配置
*.properties
userPage=20
*.xml
数据交换
xml
webservice
json
静态资源文件
css、js、html、图片、视屏

 读取指定位置下的资源文件（db.properties）

//获取同包下的资源文件，将其转化成流对象
InputStream in=PropertiesDemo.class.getResourceAsStream("db.properties");

需要专门的工具类来将流中的数据解释出

Properties p=new Properties();
        p.load(in);
        System.out.println(p.getProperty("uname"));
        System.out.println(p.getProperty("upass"));

资源文件存放在根目录下

InputStream    in=Propertie

sDemo.class.getResourceAsStream("/db.properties");

何为sourcefolder
代码不将其当做文件来处理，程序员用来做文件归类所用

将资源文件存放在web-inf下

package com.zking.pres;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ParseServlet extends HttpServlet{


    private static final long serialVersionUID = -1102190634374988166L;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doPost(req, resp);
    }
    
     @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // TODO Auto-generated method stub
         ServletContext context=req.getServletContext();
         InputStream in= context.getResourceAsStream("/WEB-INF/db.properties");
        //需要专门的工具类来将流中的数据解释出来
            Properties p=new Properties();
            p.load(in);
            System.out.println(p.getProperty("uname"));
            System.out.println(p.getProperty("upass"));
    }
}

配置Xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>Xmlpres</display-name>
    <servlet>
    <servlet-name>ParseServlet</servlet-name>
    <servlet-class>com.zking.pres.ParseServlet</servlet-class>
    </servlet>
    <servlet-mapping>
    <servlet-name>ParseServlet</servlet-name>
    <url-pattern>/ParseServlet</url-pattern>
    </servlet-mapping>
</web-app>

解析指定路径下的资源文件(全部代码)

package com.zking.pres;

import java.io.InputStream;
import java.util.List;

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

/*
 * dom4j解析
 * jdom jdk sax解析
 * 解析指定路径下的资源文件
 * 
 * 
 */
public class XmlDemo {

    public static void main(String[] args) throws Exception {
        InputStream in= XmlDemo.class.getResourceAsStream("config.xml");
        SAXReader saxReader=new SAXReader();
        Document doc=saxReader.read(in);
        System.out.println(doc.asXML());
        
        //xpath解析     能够将XML格式的串当做目录结构来进行查找
        List<Element> stuEles=    doc.selectNodes("/students/student");
        for (Element stuEle : stuEles) {
            if ("s002".equals(stuEle.attributeValue("sid"))) {
                System.out.println(stuEle.asXML());
                Element nameELe=(Element) stuEle.selectSingleNode("name");
                System.out.println(nameELe.asXML());
                System.out.println(nameELe.getText());
            }
        }
        

        
    

简单代码解析

Element stuEle=    (Element) doc.selectSingleNode("/students/student[@sid='s002']");
        System.out.println(stuEle.asXML());