使用JDOM读取XML文件的简单示例

功能：
1、使用JDOM读取Xml文件，包括Xpath读取单个节点或多个节点列表；
2、使用JDOM构建一个简单XML文档对象，并进行存储；XML模板文件

<?xml version="1.0" encoding="UTF-8"?>
<configure>
	<jdbcInfo>
		<driver>oracle.jdbc.driver.OracleDriver</driver>
		<url>jdbc:oracle:thin:@localhost:1521:orcl</url>
		<username>scott</username>
		<password>scottlxd</password>
	</jdbcInfo>
	<beans>
		<bean id="beanDao" class="com.xdzj.dao.bean1"></bean>
		<bean id="beanService" class="com.xdzj.service.bean2"></bean>
	</beans>
</configure>

Java文件

package com.work;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
import org.jdom.output.Format;
import org.jdom.output.XMLOutputter;
import org.jdom.xpath.XPath;

public class JdomReadXml {
	private static JdomReadXml jdomReadXml = null;
	private static Element rootElement = null;
	private JdomReadXml() {
	}

	public static JdomReadXml getInstance() {
		if (jdomReadXml == null) {
			jdomReadXml = new JdomReadXml();
		}
		return jdomReadXml;
	}

	/**
	 * 初始化文档对象
	 * @param filePath
	 */
	public void loadXmlResource(String filePath) {
		SAXBuilder builder = new SAXBuilder();
		try {
			Document doc = builder.build(new File(filePath));
			rootElement = doc.getRootElement();
		} catch (JDOMException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 一、使用JDOM读取单个的节点
	 * 采用Xpath路径读取
	 */
	public void initJdbcInfo() {
		try {
			Element driver = (Element) XPath.selectSingleNode(rootElement,
					"//configure/jdbcInfo/driver");
			System.out.println(driver.getText());
		} catch (JDOMException e) {
			e.printStackTrace();
		}
	}
	
	/**
	 * 二、使用JDOM读取一个节点列表
	 */
	public void initBeans(){
		try {
			List<?> elementList = XPath.selectNodes(rootElement, "//configure/beans/bean");
			for(Object e : elementList){
				Element element =  (Element)e;
				String id = element.getAttributeValue("id");
				String clszz = element.getAttributeValue("class");
				System.out.print(id + "\t" + clszz);
				System.out.println();
			}
		} catch (JDOMException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 三、使用JDOM创建Xml文件
	 */
	public void createXmlExcample(){
		Element root = new Element("selects");
		
		Element select = new Element("select");
		Element id = new Element("id");
		// 设置值
		id.addContent("1");
		Element name = new Element("name");
		name.addContent("小迪之家");
		select.addContent(id);
		select.addContent(name);
		root.addContent(select);
		
		Document document = new Document();
		document.addContent(root);
		// 使用XMLOutputter对象进行输出
		XMLOutputter out = new XMLOutputter();
		// 设置输出编码格式
		out.setFormat(Format.getCompactFormat().setEncoding("GBK"));		String docStr = out.outputString(document);
		System.out.println(docStr);
		try {
			out.output(document, new FileOutputStream("src/com/test.xml"));
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	/**
	 * 测试方法
	 * @param args
	 */
	public static void main(String[] args) {
		String filePath = "src/com/jdomXmlTemplate.xml";
		JdomReadXml jdomReadXml = JdomReadXml.getInstance();
		jdomReadXml.loadXmlResource(filePath);
		jdomReadXml.initJdbcInfo();
		jdomReadXml.initBeans();
		jdomReadXml.createXmlExcample();
	}
}