JDOM,dom4j方式解析XML

<?xml version="1.0" encoding="UTF-8"?>
<dataSources>
    <!-- 定义MySQL数据源 -->
    <dataSource id="mysql" class="xxx.xxx.xx">
        <property name="driverClassName">com.mysql.jdbc.Driver</property>
        <property name="url">jdbc:mysql://127.0.0.1:3306/userdb</property>
        <property name="username">root</property>
        <property name="password">123</property>
    </dataSource>

    <!-- 定义Oracle的数据源 -->
    <dataSource default="true" id="oracle" class="xxx.xxx.xx">
        <property name="driverClassName">com.oracle.jdbc.OracleDriver </property>
        <property name="url">jdbc:oracle:thin:@127.0.0.1:1521:ORCL </property>
        <property name="username">scott</property>
        <property name="password">tiger</property>
    </dataSource>

    <dataSource id="SQLServer" class="xxx.xxx.xx">
        <property name="driverClassName">com.oracle.jdbc.OracleDriver</property>
        <property name="url">jdbc:oracle:thin:@127.0.0.1:1521:ORCL</property>
        <property name="username">scott</property>
        <property name="password">tiger</property>
    </dataSource>

    <transaction>

    </transaction>
</dataSources>

使用JDOM解析XML文件

package com.jdom.demo;

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

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.input.SAXBuilder;
import org.jdom.xpath.XPath;

/**
 * 使用JDOM解析XML文件
 *
 * @author Administrator 补全快捷键： Ctrl+2, L
 *
 */
public class JDOMParser {
    public static void main(String[] args) throws Exception {
        //testJdomParser();
        testXPathXMLParser("oracle");
    }

    private static void testJdomParser() throws Exception {
        // 建造者设计模式
        SAXBuilder saxBuilder = new SAXBuilder();
        // 获取XML文件对应输入流
        InputStream in = JDOMParser.class.getClassLoader().getResourceAsStream("datasource.xml");
        // 通过构建器对象构建一个文档对象
        Document document = saxBuilder.build(in);
        // 获取根元素
        Element rootElement = document.getRootElement();

        // 获取根元素下面所有子元素
        // getChildren() 获取所有子元素集合
        // getChildren("元素名称") // 获取指定元素名称的元素集合
        List<Element> childList = rootElement.getChildren("dataSource");

        for (Element element : childList) {
            // 获取id属性值
            String id = element.getAttributeValue("id");
            String clazz = element.getAttributeValue("class");
            System.out.println("id=" + id + "-----class=" + clazz);
            // 获取所有的property子节点
            List<Element> propertyChild = element.getChildren("property");

            for (Element childEl : propertyChild) {
                String name = childEl.getAttributeValue("name"); // 获取元素name属性值
                String text = childEl.getTextTrim(); // 获取元素中的内容

                System.out.println("name=" + name + "=========content=" + text);
            }
            System.out.println("--------------------------");
        }
    }

    /**
     * 使用XPath选取节点
     * http://www.cnblogs.com/hoojo/archive/2011/08/11/2134638.html XPath解析
     */
    private static void testXPathXMLParser(String dataSourceId) throws Exception{
        // 建造者设计模式
        SAXBuilder saxBuilder = new SAXBuilder();
        // 获取XML文件对应输入流
        InputStream in = JDOMParser.class.getClassLoader().getResourceAsStream("datasource.xml");
        // 通过构建器对象构建一个文档对象
        Document document = saxBuilder.build(in);
        // 获取根元素
//        Element rootElement = document.getRootElement();
        // path: XPath表达式
        XPath xpath = XPath.newInstance("dataSources/dataSource[@id='"+dataSourceId+"']");
        Element dataSource = (Element) xpath.selectSingleNode(document);
        // "//" 选取配置元素组成集合，不考虑位置
        XPath propXpath = XPath.newInstance("property");
        List<Element> nodes = propXpath.selectNodes(dataSource); // 从选择到dataSource元素下面选择子节点
        for (Element el : nodes) {
            System.out.println(el.getAttributeValue("name")+"-------------"+el.getTextTrim());
        }
    }
}

dom4j常规方式解析 

package com.dom4j.demo;

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

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

public class Dom4jParser {
    public static void main(String[] args) throws Exception {
        dom4jXpath("mysql");
    }

    /**
     * dom4j常规方式解析 -> 使用命名空间方式解析
     * @throws Exception
     */
    private static void dom4j() throws Exception {
        // 创建SaxReader对象
        SAXReader reader = new SAXReader();
        InputStream in = Dom4jParser.class.getClassLoader().getResourceAsStream("datasource.xml");
        // 获取到文档对象
        Document document = reader.read(in);
        // 获取根元素对象
        Element rootElement = document.getRootElement();
        // System.out.println(rootElement);
        // 获取根元素下面所有子元素
        // List<Element> elements = rootElement.elements();
        // 获取根元素下面指定元素名称的子元素集合
        List<Element> elements = rootElement.elements("dataSource");

        for (Element el : elements) {
            System.out.println(el.attributeValue("id") + "-----" + el.attributeValue("class"));
            // 获取el元素下面所有子元素
            List<Element> childList = el.elements("property");

            for (Element childEl : childList) {
                String name = childEl.attributeValue("name");
                String text = childEl.getTextTrim();
                System.out.println(name + "----------" + text);
            }
            System.out.println("------------------------------------------");
        }
    }

    /**
     * dom4j方式解析使用XPath
     * @throws Exception
     */
    private static void dom4jXpath(String dataSourceId) throws Exception {
        // 创建SaxReader对象
        SAXReader reader = new SAXReader();
        InputStream in = Dom4jParser.class.getClassLoader().getResourceAsStream("datasource.xml");
        // 获取到文档对象
        Document document = reader.read(in);

        XPath xpath = document.createXPath("dataSources/dataSource[@id='"+dataSourceId+"']");
        Element dataSourceNode = (Element) xpath.selectSingleNode(document);
        System.out.println(dataSourceNode.attributeValue("id")+"----"+dataSourceNode.attributeValue("class"));

        xpath = document.createXPath("property");
        List<Element> propList = xpath.selectNodes(dataSourceNode);

        for (Element el : propList) {
             String name = el.attributeValue("name");
             String text = el.getTextTrim();
             System.out.println(name+"--------------"+text);
        }
    }
}