servlet知识点小结

        一、servlet基础

                 1、什么是servlet?

                 2、如何开发一个servlet?

                 3、什么是servlet容器?

                 4、了解http协议

        二、servlet核心

                 1、servlet核心类与接口

                           a,Servlet接口

                           b,GenericServlet抽象类

                         c,ServletConfig接口

                                    String getInitParameter(String paraName);

                                    ServletContext getServletContext();

                           d,HttpServlet抽象类

                           e,HttpServletRequest接口(ServletRequest)

                                    String getParameter(String paraName);

                                    String[] getParameterValues(String paraName);

                                    setCharacterEncoding(String code);

                                    String getRequestURI();

                                    setAttribute(String name,Object obj);

                                    Object getAttribute(String name);

                                    removeAttribute(String name);

                                    RequestDispatcher getRequestDispatcher(String url);

                                    Cookie[] getCookies();

                                    String getContextPath();

                                    getRemoteAddr();

                           f,HttpServletResponse接口(ServletResponse)

                                    setContentType(String type);

                                    PrintWriter getWriter();

                                    sendRedirect(String url);

                                    addCookie(Cookie cookie);

                                    encodeURL(String url);

                                    encodeRedirectURL(String url);

                           g, ServletContext接口

                                    setAttribute(String name,Object obj);

                                    Object getAttribute(String name);

                                    removeAttribute(String name);

                                    String getRealPath(String url);

                                    String getInitParameter(String paraName);

                 2、servlet的生命周期

                           1)servlet的生命周期分成哪几个阶段?

                           2)如何override init方法。

                           3)load-on-starup参数

                           4)如何配置初始化参数(init-param)

                 3、表单处理

                           1)如何获得表单的参数？

                           2)如何获取表单的中文参数值?

                 4、get方式与post方式

                           1)哪一些请求是get请求方式

                           2)哪一些请求是post请求方式

                           3)二者的区别

                 5、转发与重定向

                           1)什么是转发？

                           2)如何转发？以及要注意的问题？

                           3)转发的特点？

                           4)什么是重定向？

                           5)如何重定向？以及要注意的问题？

                           6)重定向的特点？

                           7)二者的区别?

        三、状态管理

                           1) 什么是状态管理?

                           2) cookie技术

                                    a,什么是cookie?

                                    b,cookie如何创建?

                                             Cookie c = new Cookie("username","abc");

                                             response.addCookie(c);

                                    c,cookie的编码问题?

                                             String URLEncoder.encode(String name,String code);

                                             String URLDecoder.decode(String name,String code);

                                    d,cookie的查询

                                             Cookie[] request.getCookies();

                                             String cookie.getName();

                                             String cookie.getValue();

                                    f,cookie的生存时间

                                              cookie.setMaxAge(int seconds)

                                    g,cookie的路径问题

                                              cookie.setPath(String path)

                                    h,cookie的限制

                           3) session技术

                                    a, 什么是session?

                                    b, 如何获得session?

                                             HttpSession request.getSession();

                                             HttpSession request.getSession(boolean flag);

                                    c,session的常用方法

                                             setAttribute(String name,Object obj);

                                             Object getAttribute(String name);

                                             removeAttribute(String name);

                                             String getId();

                                    d, session的超时

                                             setMaxInactiveInterval(int seconds)

                                    e,删除

                                             invalidate();

                                    g,用户禁止cookie以后，如何继续使用session?

                                             使用url重写

        四、数据库访问

                           1、使用jdbc访问数据库

                           2、dao

                                    a,什么是dao?

                                    b,如何写一个dao?

         五、过滤器与监听器

                            1、什么是过滤器?

                            2、如何写一个过滤器?

                            3、过滤器初始化参数？

                            4、优先级

                            5、什么是监听器？

                            6、如何写一个监听器?

        六、案例

                           1、session验证

                           2、验证码

                           3、购物车

                           4、员工的增删改查

       

        练习：

                           “交友平台"

                 功能：

                           1、注册

                                    a,将用户注册信息插入数据库

                                    b,验证码

                                    c,用户名要求唯一

                           2、登录

                                    a,验证用户名和密码

                           3、用户列表

                                    a,显示所有已注册用户的信息(除了真实姓名与

                                    电话)

                                    b,点击“详细"链接, 会跳转到“用户详细信息列表"

                           4、用户详细信息列表

                                    a,列出用户的真实姓名和电话

                                    b, 如果是当前用户(比如，sdd登录了该系统，

                                    并且，点击的也是sdd用户的“详细”链接),

                                    则可以上传照片。

                                    c, 查看照片(会显示该用户的所有照片)。

                                    d, 如果用户没有登录，则看不到照片，也

                                    不能上传照片。

                                   

                 实现:

                           1、注册

                                    a, 创建一个表t_frienduser:

                                    create table t_frienduser(

                                             id int primary key auto_increment,

                                             username varchar(50) unique,

                                             name varchar(100),

                                             pwd varchar(20),

                                             age int,

                                             gender char(1),

                                             phone varchar(20)

                                    );

                                    create table t_friendpic(

                                             id int primary key auto_increment,

                                             picName varchar(50),

                                             userId int

                                    );

                                    使用用户的id来创建一个文件夹，用于

                           存放照片文件。

                                    比如 建一个文件夹 pic_1

                           2、登录

                           3、用户列表

                           4、用户详细信息列表

                                    b,只需要比较session中保存的用户的id

                           与点击“详细”链接时的id,如果相等，则是

                           当前用户，显示上传文件。

                                    c,通过用户的id,查询t_friendpic表，获得

                                    照片文件的名称。

                                    d,上传文件时，要将文件保存到pic_id文件

                                    夹，并且要文件名保存到t_friendpic表。