2.工厂BeanFactory类,读取工厂配置文件的数据,创建Dao对象,Manager对象

package com.bjpowernode.drp.util;import java.util.HashMap;import java.util.Map;import org.dom4j.Document;import org.dom4j.DocumentException;import org.dom4j.Element;import org.dom4j.io.SAXReader;import com.bjpowernode.drp.basedata.dao.ItemDao;import com.bjpowernode.drp.basedata.manager.ItemManager;/** * 抽象工厂,主要创建两个系列的产品： *   1、Manager系列 *   2、Dao系列产品 * @author Administrator * */public class BeanFactory {private static BeanFactory instance = new BeanFactory();private final String beansConfigFile = "beans-config.xml";//保存Service相关对象private Map serviceMap = new HashMap();//保存Dao相关对象private Map daoMap = new HashMap();private Document doc;private BeanFactory() {try {doc = new SAXReader().read(Thread.currentThread().getContextClassLoader().getResourceAsStream(beansConfigFile));} catch (DocumentException e) {e.printStackTrace();throw new RuntimeException();}}public static BeanFactory getInstance() {return instance;}/** * 根据产品编号取得Service系列产品 * @param beanId * @return */public synchronized Object getServiceObject(Class c){//如果存在相关对象实例，返回if (serviceMap.containsKey(c.getName())) {return serviceMap.get(c.getName());}Element beanElt = (Element)doc.selectSingleNode("//service[@id=\"" + c.getName() + "\"]");String className = beanElt.attributeValue("class");Object service = null;try {service = Class.forName(className).newInstance();//将创建好多的对象放到Map中serviceMap.put(c.getName(), service);} catch (Exception e) {throw new RuntimeException();}return service;}/** * 根据产品编号取得Service系列产品 * @param beanId * @return */public synchronized Object getDaoObject(Class c){//如果存在相关对象实例，返回if (daoMap.containsKey(c.getName())) {return daoMap.get(c.getName());}Element beanElt = (Element)doc.selectSingleNode("//dao[@id=\"" + c.getName() + "\"]");String className = beanElt.attributeValue("class");Object dao = null;try {dao = Class.forName(className).newInstance();//将创建好多的对象放到Map中daoMap.put(c.getName(), dao);} catch (Exception e) {throw new RuntimeException();}return dao;}public static void main(String[] args) {//ItemManager itemManager = (ItemManager)BeanFactory.getInstance().getServiceObject("itemManager");//System.out.println(itemManager);//ItemDao itemDao = (ItemDao)BeanFactory.getInstance().getDaoObject("com.bjpowernode.drp.basedata.dao.ItemDao");ItemDao itemDao = (ItemDao)BeanFactory.getInstance().getDaoObject(ItemDao.class);System.out.println(itemDao);}}