（三）dom4j+Xpath的简单路径表达式获取节点元素内容和属性值

<?xml version="1.0" encoding="UTF-8"?>
<config>
    <database-info>
        <driver-name>com.mysql.jdbc.Driver</driver-name>
        <url>jdbc:mysql://localhost:3306/sys?serverTimezone=GMT%2B8</url>
        <user>root</user>
        <password>123</password>
    </database-info>
</config>

package com.zda.xml;


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

public class SysConfigParser {

    /**
     * @param args
     */
    public static void main(String[] args) {
        try {
            //创建解析器
            SAXReader reader = new SAXReader();
            //通过解析器的read方法将配置文件读取到内存中，生成一个Dcoumente【org.dom4j】对象树
            Document document = reader.read("conf/sys-config.xml");
            //driver-name节点元素的路径：config -> database-info -> driver-name
            // driver-name节点元素的xpath路径：/config/database-info/driver-name
            Element driverNameElt = (Element) document.selectSingleNode("/config/database-info/driver-name");
            //获取driverNameElt节点元素对象的文本内容
            String driverName = driverNameElt.getStringValue();
            System.out.println(driverName);
            
            //url节点元素的路径： config -> database-info -> url
            //url节点元素的xpath路径： /config/database-info/url
            //url节点元素的xpath路径： config//url
            //url节点元素的xpath路径： //url
            Element urlElt = (Element) document.selectSingleNode("/config//url");
            String url = urlElt.getStringValue();
            System.out.println(url);
            
            //user节点元素的路径:config -> database-info -> user
            //user节点元素的xpath路径:/config/database-info/user
            //user节点元素的xpath路径:config//user
            //user节点元素的xpath路径://user
            Element userElt = (Element) document.selectObject("//user");
            String user = userElt.getText();
            System.out.println(user);
            //获取userElt节点元素对象的name属性对象
            Attribute portAttr = userElt.attribute("name");
            //获取portAttr节点name属性对象的值，方法1
            String port = portAttr.getStringValue();
            System.out.println(port);
            //获取portAttr节点name属性对象的值，方法2
            String portValue = userElt.attributeValue("name");
            System.out.println(portValue);
            
            
            Element passwordElt = (Element) document.selectSingleNode("//password");
            String password = passwordElt.getTextTrim();
            System.out.println(password);
            
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}