利用JDOM解析xml檔案

利用JDOM解析xml檔案

JDOM是一個開源項目，它基於樹型結構，利用純JAVA的技術對XML文檔實現解析、產生、序列化以及多種操作。JDOM直接為JAVA編程服務。它利用更為強有力的JAVA語言的諸多特性（方法重載、集合概念以及映射），把SAX和DOM的功能有效地結合起來。
JDOM的官方地址：http://www.jdom.org/
參考：馬士兵 設計模式 原廠模式
1.首先建立一個介面和2個類，為後續做準備

[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("飛機在翱翔.....");}}

[Train.java]

package com.njupt.zhb.test;public class Train implements Moveable{@Overridepublic void run() {System.out.println("火車在飛奔....");}}

2.建立一個介面，主程式可以調用getBean方法，獲得相應的對象。

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

3.需要解析的xml檔案如下：

<?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.解析檔案的主類，實現了BeanFactory介面。

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>();//用於存放解析出來的id和對象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");//獲得此節點下的所有值System.out.println(list.size());for (int i = 0; i < list.size(); i++) {Element bean = (Element) list.get(i);String id = bean.getAttributeValue("id");//獲得id對應的值String clazz = bean.getAttributeValue("class");//獲得class對應的值Object o = Class.forName(clazz).newInstance();//Java反射機制，根據類名產生對象mapContainer.put(id, o);//儲存到map中System.out.println(id + " " + clazz);}}@Overridepublic Object getBean(String id) {return mapContainer.get(id);}}

5.主程式TestMain調用。

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");//獲得標籤為train的對象Moveable m1 = (Moveable)obj1;//介面調用子類m1.run();// //----------------------Object obj2 = f.getBean("plane");Moveable m2 = (Moveable) obj2;m2.run();}}

實驗結果：

2train com.njupt.zhb.test.Trainplane com.njupt.zhb.test.Plane火車在飛奔....飛機在翱翔.....

原始碼：http://download.csdn.net/detail/nuptboyzhb/5756633