1.1 上次课内容回顾:

注解:

* JDK中的三个注解:[/align]    * 自定义注解:        * @interface        * 注解类型:基本类型,String,Class,注解,枚举,以上类型的一维数组.    * 注解的反射:Servlet3.0    * 注解开发:    * 文件上传:    * 异步请求:动态代理：    * Proxy.newProxyInstance(ClassLoader cl,Class[] interfaces,InvocationHandler handler);    * 如何增强类中的某个方法:类加载器:    * 引导类加载器:    * 扩展类加载器:    * 应用类加载器:

1.2 网上商城的实战的案例:1.2.1 需求：

1.2.2 数据库设计:1.2.3 网上商城用户模块的代码实现:(前台)1.2.3.1 编写一个通用的Servlet:传统方式的开发一个请求对应一个Servlet:这样的话会导致一个模块的Servlet过多,导致整个项目的Servlet都会很多.能不能做一个处理?让一个模块致用一个Servlet处理请求.注册:登录:激活:商品查询所有：商品查询某个：传统:

public class UserServlet extends HttpServlet{    public void service(HttpServletRequest req,HttpServletResponse resp){        // 接收参数:        String methodName = request.getParameter(“method”);        if(“regist”.equals(methodName)){            regist(req,resp);        }else if(“login”.equals(methodName)){            login(req,resp);       }   }   public void regist(HttpServletRequest req,HttpServletResponse resp){   }   public void login(HttpServletRequest req,HttpServletResponse resp){   }}public class ProductServlet extends HttpServlet{    public void service(HttpServletRequest req,HttpServletResponse resp){        // 接收参数:        String methodName = request.getParameter(“method”);        if(“findAll”.equals(methodName)){            findAll(req,resp);        }else if(“findById”.equals(methodName)){            findById(req,resp);       }   }   public void findAll(HttpServletRequest req,HttpServletResponse resp){   }   public void findById(HttpServletRequest req,HttpServletResponse resp){   }}

反射:

public class BaseServlet extends HttpServlet{     public void service(HttpServletRequest req,HttpServletResponse resp){          // http://localhost:8080/store_2.0/UserServlet?method=regist          // http://localhost:8080/store_2.0/ProductServlet?method=findAll          String methodName = request.getParameter(“method”);          // 获得Class:          Class clazz = this.getClass();          Method method = clazz.getMethod(methodName,HttpServletRequest.class,HttpSerlvetResponse.class);          String path = (String)method.invoke(this,req,resp);          if(path != null){              req.getRequestDispatcher(path).forward(req,resp);          }     }}public class UserServlet extends BaseServlet {   public String regist(HttpServletRequest req,HttpServletResponse resp){         return “/login.jsp”;   }   public String login(HttpServletRequest req,HttpServletResponse resp){         return “/index.jsp”;   }}public class ProductServlet extends BaseServlet{   public String findAll(HttpServletRequest req,HttpServletResponse resp){   }   public String findById(HttpServletRequest req,HttpServletResponse resp){   }}