需求:在UserServlet中调用UserService的add方法
1.UserService类
public class UserService{
public void add(){
System.out.println("add......");
}
}
2.创建xml配置文件并配置创建的对象类
<?xml version="1.0" encoding="UTF-8"?>
<beans>
<bean id="userService" class="UserService"/>
</beans>
3.创建工厂类，使用dom4j解析配置文件并利用反射创建对象
public class Factory{
public static getUserService(){
//1.dom4j解析获取class的值
String className = "UserService";
//2.通过反射创建对象
Class clazz = Class.forName(className);
UserService userService = (UserService)clazz.newInstance();
return userService;
}
}
4.在UserServlet中调用UserService的add方法
class UserServlet extends HttpServlet{
UserService userService = Factory.getUserService();
userService.fun();
}