使用beanfactory管理bean

public final class BeanFactory {
 
 private static Map<String, Object> map = null;
 static {
  map = new HashMap<String, Object>();
  try {
   Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(
     FileHelper.getResourceAsStream("/beanfactory.xml"));
   NodeList daos = doc.getElementsByTagName("bean");
   Element e = null;
   int length = daos.getLength();
   for (int i = 0; i < length; i++) {
    e = (Element) daos.item(i);
    map.put(e.getAttribute("name"), Class.forName(e.getAttribute("class")).newInstance());
   }
  } catch (Exception ex) {
   ex.printStackTrace();
  }
 }

 
 /**
  * 根据bean的名称，获取相应的bean
  * @param beanName
  * @return
  */
 public static Object getBean(String beanName) {
  return map.get(beanName);
 }
}