Servlet 示例 类定义 编写接收 HTTP 请求并进行 HTTP 响应的 Servlet 需要继承 javax.servlet.http.HttpServlet。 1 public class LoginAction extends HttpServlet { 2 // Code goes on. 3 } 大纲 Web 基础 Servlet 概述 Servlet 编程 Servlet 生命周期 生命周期 Servlet 配置 Servlet 部署 Servlet 示例 重写 doGet 方法 父类 HttpServlet 的 doGet 方法是空的，没有实现任何代码，子 类需要重写此方法。 2 public void doGet(HttpServletRequest request, HttpServletResponse response) 3 throws ServletException doGet() doPost() Get Request Post Request Response Response Web Server HttpServlet subclass 注意： 方法由 HttpServlet 的子类实现 大纲 Web 基础 Servlet 概述 Servlet 编程 Servlet 生命周期 Servlet 配置 Servlet 部署 Servlet

doGet() doPost() Get Request Post Request Response Response Web Server HttpServlet subclass 注意： 方法由 HttpServlet 的子类实现

HTTP 响应的 Servlet 需要继承 javax.servlet.http.HttpServlet。 1 public class LoginAction extends HttpServlet { 2 // Code goes on. 3 } 16.3.3 重写 doGet 方法 父类 HttpServlet 的 doGet 方法是空的，没有实现任何代码，子类需要重写此方法。 2 public doGet() doPost() Get Request Post Request Response Response Web Server HttpServlet subclass 注意： 方法由 HttpServlet 的子类实现 图 16.2 Servlet 处理流程 16.5 Servlet 配置 • Servlet 作为 Web 组件可以处理 HTTP 请求/响应，因此对外要求一个唯一的 例如 Servlet 类 LoginAction： 1 package ouc.java. servlet ; 2 public class LoginAction extends HttpServlet { 3 // 4 } 存放路径为：/WEB-INF/classes/ouc/java/servlet/LoginAction.class . . . . . . . . . . .

@WebServlet(name = "loginServlet", urlPatterns = "/login") public class LoginServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws "formFilterLoginServlet", urlPatterns = "/formfilterlogin") public class FormFilterLoginServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws @WebServlet(name = "permissionServlet", urlPatterns = "/permission") public class PermissionServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws

大纲 Java Web 应用的开发演化 经典 MVC 框架 - Struts 2 本节习题 Servlet 方式 1 public class LoginServlet extends HttpServlet { 3 @Override 4 protected void doPost(HttpServletRequest req, HttpServletResponse resp) 5 throws

会话跟踪技术 本节习题 Java EE 会话对象 会话对象的应用示例 O 会话对象销毁（编程一般在注销功能中） 1 public class LogoutAction extends HttpServlet { 2 public void doGet(HttpServletRequest request, HttpServletResponse response) { 3 HttpSession

Java Web 应用的开发演化 MVC 模式示例 Spring MVC 数据绑定和表单标签库 Servlet 方式 public class LoginServlet extends HttpServlet { @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException

Base() { // 委托 Base() 构造函数 value2 = value; } }; class Subclass : public Base { public: using Base::Base; // 继承构造 }; int main() { Subclass s(3); std::cout << s.value1 << std::endl; std::cout << 在传统 C++ 中，经常容易发生意外重载虚函数的事情。例如： struct Base { virtual void foo(); }; struct SubClass: Base { void foo(); }; SubClass::foo 可能并不是程序员尝试重载虚函数，只是恰好加入了一个具有相同名字的函数。另 一个可能的情形是，当基类的虚函数被删除后，子类拥有旧的函数就不再重载该虚拟函数并摇身一变成 关键字将显式的告知编译器进行重载，编译器将检查基函 数是否存在这样的其函数签名一致的虚函数，否则将无法通过编译： struct Base { virtual void foo(int); }; struct SubClass: Base { virtual void foo(int) override; // 合法 virtual void foo(float) override; // 非法, 父类没有此虚函数

in a Task subclass. The function name will be used as the task name when invoking. Subclass Task (Task itself is intended to be abstract), define a run method, and instantiate your subclass at module level the function itself as the first argument (see 使用 @task 定制子类 for details.) task_class: The Task subclass used to wrap the decorated function. Defaults to WrappedCallableTask. aliases: An iterable of string you want to take advantage of class metaprogramming or similar techniques. Specifically, any Task subclass which is designed to take in a callable as its first constructor argument (as the built-in WrappedCallableTask

in a Task subclass. The function name will be used as the task name when invoking. Subclass Task (Task itself is intended to be abstract), define a run method, and instantiate your subclass at module level the function itself as the first argument (see 使用 @task 定制子类 for details.) task_class: The Task subclass used to wrap the decorated function. Defaults to WrappedCallableTask. aliases: An iterable of string you want to take advantage of class metaprogramming or similar techniques. Specifically, any Task subclass which is designed to take in a callable as its first constructor argument (as the built-in WrappedCallableTask