JavaWeb项目--网上商城 （6-3）

<?xml version="1.0" encoding="UTF-8"?>
<beans>
   <bean id="ProductDao" class="com.itheima.dao.impl.ProductDaoImpl"/>
  <!--  <bean id="ProductDao" class="com.itheima.dao.impl.ProductDaoHibImpl"/> -->
   <bean id="UserDao" class="com.itheima.dao.impl.UserDaoImpl"/>
   <bean id="CategoryDao" class="com.itheima.dao.impl.CategoryDaoImpl"/>
   <bean id="OrderDao" class="com.itheima.dao.impl.OrderDaoImpl"/>
   
   <bean id="ProductService" class="com.itheima.service.impl.ProductServiceImpl"/>
   <bean id="UserService" class="com.itheima.service.impl.UserServiceImpl"/>
   <bean id="CategoryService" class="com.itheima.service.impl.CategoryServiceImpl"/>
   <bean id="OrderService" class="com.itheima.service.impl.OrderServiceImpl"/>
</beans>

package com.itheima.utils;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

/**
 * 获取javabean的工厂
 * @author Administrator
 *
 */
public class BeanFactory {

    public static Object getBean(String id){
        try {
            //1.获取document对象
            Document doc=new SAXReader().read(BeanFactory.class.getClassLoader().getResourceAsStream("beans.xml"));
            
            //2.调用api selectSingleNode(表达式)
            Element beanEle=(Element) doc.selectSingleNode("//bean[@id=‘"+id+"‘]");
            
            //3.获取元素的class属性
            String classValue = beanEle.attributeValue("class");
            
            //4.通过反射返回实现类的对象
            Object newInstance = Class.forName(classValue).newInstance();
            return newInstance;
        }  catch (Exception e) {
            e.printStackTrace();
            System.out.println("获取bean失败");
        }
        return null;
    }
    
    public static void main(String[] args) throws Exception {
        System.out.println(getBean("ProductDao1"));
    }
}