利用JDOM解析xml文件

利用JDOM解析xml文件

JDOM是一个开源项目，它基于树型结构，利用纯JAVA的技术对XML文档实现解析、生成、序列化以及多种操作。JDOM直接为JAVA编程服务。它利用更为强有力的JAVA语言的诸多特性（方法重载、集合概念以及映射），把SAX和DOM的功能有效地结合起来。
JDOM的官方地址：http://www.jdom.org/
参考：马士兵 设计模式 工厂模式
1.首先新建一个接口和2个类，为后续做准备

[Moveable.java]

package com.njupt.zhb.test;public interface Moveable {void run();}

[Plane.java]

package com.njupt.zhb.test;public class Plane implements Moveable {@Overridepublic void run() {// TODO Auto-generated method stubSystem.out.println("飞机在翱翔.....");}}

[Train.java]

package com.njupt.zhb.test;public class Train implements Moveable{@Overridepublic void run() {System.out.println("火车在飞奔....");}}

2.新建一个接口，主程序可以调用getBean方法，获得相应的对象。

package com.njupt.zhb.test;public interface BeanFactory {Object getBean(String id);}

3.需要解析的xml文件如下：

<?xml version="1.0" encoding="UTF-8"?><beans><bean     id="train"    class="com.njupt.zhb.test.Train"></bean><bean    id="plane"    class="com.njupt.zhb.test.Plane"></bean></beans>

4.解析文件的主类，实现了BeanFactory接口。

package com.njupt.zhb.test;import java.util.HashMap;import java.util.List;import java.util.Map;import org.jdom.Document;import org.jdom.Element;import org.jdom.input.SAXBuilder;import org.jdom.xpath.XPath;public class ClassPathXmlApplicationContext implements BeanFactory {private Map<String, Object> mapContainer = new HashMap<String, Object>();//用于存放解析出来的id和对象public ClassPathXmlApplicationContext(String fileName) throws Exception {SAXBuilder sb = new SAXBuilder();Document doc = sb.build(this.getClass().getClassLoader().getResourceAsStream(fileName));Element root = doc.getRootElement();List list = XPath.selectNodes(root, "/beans/bean");//获得此节点下的所有值System.out.println(list.size());for (int i = 0; i < list.size(); i++) {Element bean = (Element) list.get(i);String id = bean.getAttributeValue("id");//获得id对应的值String clazz = bean.getAttributeValue("class");//获得class对应的值Object o = Class.forName(clazz).newInstance();//Java反射机制，根据类名生成对象mapContainer.put(id, o);//保存到map中System.out.println(id + " " + clazz);}}@Overridepublic Object getBean(String id) {return mapContainer.get(id);}}

5.主程序TestMain调用。

package com.njupt.zhb.test;public class TestMain {public static void main(String[] args) throws Exception {BeanFactory f = new ClassPathXmlApplicationContext("com/njupt/zhb/test/sample.xml");Object obj1 = f.getBean("train");//获得标签为train的对象Moveable m1 = (Moveable)obj1;//接口调用子类m1.run();// //----------------------Object obj2 = f.getBean("plane");Moveable m2 = (Moveable) obj2;m2.run();}}

实验结果：

2train com.njupt.zhb.test.Trainplane com.njupt.zhb.test.Plane火车在飞奔....飞机在翱翔.....

源代码下载地址：http://download.csdn.net/detail/nuptboyzhb/5756633