邏輯描述：
現(xiàn)在我們想在B層和D層加上接口層，并使用工廠。而我們可以將創(chuàng)建B和創(chuàng)建D看作是兩個系列，然后就可以使用抽象工廠進(jìn)行創(chuàng)建了。
配置文件：beans-config.xml。service-class與dao-class分別對應(yīng)兩個系列的產(chǎn)品。子菜單中id對應(yīng)接口的命名空間，class對應(yīng)實現(xiàn)類的命名空間。
復(fù)制代碼代碼如下:
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<?xml version="1.0" encoding="UTF-8"?>
<beans>
<service-class>
<service id="com.xxjstgb.drp.basedata.manager.ItemManager" class="com.xxjstgb.drp.basedata.manager.ItemManagerImpl" />
<service id="com.xxjstgb.drp.flowcard.manager.FlowCardManager" class="com.xxjstgb.drp.flowcard.manager.impl.FlowCardManagerImpl" />
</service-class>
<dao-class>
<dao id="com.xxjstgb.drp.basedata.dao.ItemDao" class="com.xxjstgb.drp.basedata.dao.ItemDao4OracleImpl" />
<dao id="com.xxjstgb.drp.flowcard.dao.FlowCardDao" class="com.xxjstgb.drp.flowcard.dao.impl.FlowCardDaoImpl" />
</dao-class>
</beans>
抽象工廠：BeanFactory。通過讀取配置文件，取得相關(guān)對象，并將相關(guān)創(chuàng)建好的對象保存在Map中。
復(fù)制代碼代碼如下:
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package com.xxjstgb.drp.util;
import java.util.HashMap;
import java.util.Map;
//dom4j
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import com.xxjstgb.drp.basedata.dao.ItemDao;
import com.xxjstgb.drp.basedata.manager.ItemManager;
import com.xxjstgb.drp.flowcard.dao.FlowCardDao;
import com.xxjstgb.drp.flowcard.manager.FlowCardManager;
/**
* 抽象工廠，主要創(chuàng)建兩個系列的產(chǎn)品
* 1、Manager系列
* 2、Dao系列產(chǎn)品
* @author liuzhengquan
*
*/
public class BeanFactory {
private static BeanFactory instance=new BeanFactory();
//系統(tǒng)缺省配置文件名稱
private final String beansConfigFile="beans-config.xml";
//保存Dao相關(guān)對象
private Document doc;
/*
* key=配置文件中的id值
* value=對應(yīng)了該Id的對象
*/
private Map serviceMap = new HashMap();//保存Service相關(guān)對象
private Map daoMap = new HashMap();//保存Dao相關(guān)對象
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;
}
/**
* 根據(jù)產(chǎn)品編號取得Service系列產(chǎn)品
* @param serviceId
* @return
*/
public synchronized Object getServiceObject(Class c){
//如果存在相關(guān)對象實例，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();
//將創(chuàng)建好的對象放到Map中
serviceMap.put(c.getName(), service);
} catch (Exception e) {
throw new RuntimeException();
}
return service;
}
/**
* 根據(jù)產(chǎn)品編號取得Dao系列產(chǎn)品
* @param daoId
* @return
*/
public synchronized Object getDaoObject(Class c){
//如果存在相關(guān)對象實例，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();
//將創(chuàng)建好的對象放到Map中
daoMap.put(c.getName(), dao);
} catch (Exception e) {
throw new RuntimeException();
}
return dao;
}
/**
* 測試
* @param args
*/
public static void main(String[] args){
ItemManager itemManager=(ItemManager)BeanFactory.getInstance().getServiceObject(ItemManager.class);
System.out.println("itemManager"+itemManager);
ItemDao itemDao=(ItemDao)BeanFactory.getInstance().getDaoObject(ItemDao.class);
System.out.println("itemDao:"+itemDao);
FlowCardManager flowCardManager=(FlowCardManager)BeanFactory.getInstance().getServiceObject(FlowCardManager.class);
//FlowCardManager flowCardManager=new FlowCardManagerImpl();
System.out.println(flowCardManager);
FlowCardDao flowCardDao=(FlowCardDao)BeanFactory.getInstance().getDaoObject(FlowCardDao.class);
//FlowCardDao flowCardDao=new FlowCardDaoImpl();
System.out.println("flowCardDao:"+flowCardDao);
}
}
