1 public interface Moveable {
2     void run();
3 }

1 public class Car implements Moveable{
2     public void run() {
3         System.out.println("car run");
4     }
5 }

1 public class Train implements Moveable{
2     public void run() {
3         System.out.println("train run");
4     }
5 }

1 public interface BeanFactory {
2     Object getBean(String id);
3 }

 1 public class ClassPathXmlApplicationContext implements BeanFactory {
 2     private Map<String,Object> container = new HashMap<String,Object>();
 3     /**
 4      * 采用JDom解析applicationContext.xml
 5      * 具体包可以网上下载
 6      * @param fileName
 7      * @throws JDOMException
 8      * @throws IOException
 9      * @throws InstantiationException
10      * @throws IllegalAccessException
11      * @throws ClassNotFoundException
12      */
13     public ClassPathXmlApplicationContext(String fileName) throws JDOMException, IOException, InstantiationException, IllegalAccessException, ClassNotFoundException {
14         SAXBuilder sb = new SAXBuilder();
15         Document doc = sb.build(this.getClass().getResourceAsStream(fileName));
16         Element root = doc.getRootElement();
17         List list = XPath.selectNodes(root, "/beans/bean");
18 //        System.out.println(list.size());
19
20         for(int i=0; i<list.size(); i++) {
21             Element bean = (Element) list.get(i);
22             String id = bean.getAttributeValue("id");
23             String clazz = bean.getAttributeValue("class");
24             Object o = Class.forName(clazz).newInstance();
25             container.put(id, o);
26 //            System.out.println(" id: " + id + " class: " + clazz);
27         }
28     }
29     @Override
30     public Object getBean(String id) {
31         return container.get(id);
32     }
33
34 }

1 <!--Spring配置文件applicationContext.xml-->
2 <?xml version="1.0" encoding="UTF-8"?>
3 <beans>
4   <bean id="v" class="com.learn.www.factory.spring.Car">
5   </bean>
6 </beans>

 1 public class Test {
 2
 3     /**
 4      * @param args
 5      * @throws IOException
 6      * @throws ClassNotFoundException
 7      * @throws IllegalAccessException
 8      * @throws InstantiationException
 9      * @throws JDOMException
10      */
11     public static void main(String[] args) throws IOException, InstantiationException, IllegalAccessException, ClassNotFoundException, JDOMException {
12         BeanFactory f = new ClassPathXmlApplicationContext("applicationContext.xml");
13         Object o = f.getBean("v");
14         Moveable m = (Moveable)o;
15         m.run();
16     }
17
18 }