小節(jié)練習(xí)題答案2.0cookie和session jsp改造案例

1、記住用戶名訓(xùn)練描述1_用戶首次訪問系統(tǒng)登錄界面顯示如下效果2_用戶錄入賬戶,密碼而且選中記住用戶名,點(diǎn)擊登錄按鈕3_登錄失敗顯示如下效果4_登錄成功顯示如下效果:5_此時用戶再次訪問登錄界面,顯示如下效果:操作步驟描述1_建立倉庫day38_homework,建立以下表CREATE TABLE users( uid INT PRIMARY KEY AUTO_INCREMENT, username VARCHAR(32), PASSWORD VARCHAR(32);INSERT INTO users VALUES(1,jack,jack);INSERT INTO users VALUES(2,l

2、ucy,lucy);INSERT INTO users VALUES(3,mary,mary);2_在ServletDemo02中向客戶端輸出表單,用于接收用戶的賬戶和密碼,效果如下代碼如下:response.setContentType(text/html;charset=utf-8);PrintWriter out = response.getWriter();String str=;String str01=;str=記住用戶名;str01=用戶;out.println();out.println(str01);out.println(密碼);out.println(str);out.p

3、rintln();out.println();3_在ServletDemo03中接收用戶表單數(shù)據(jù),實現(xiàn)登錄操作 response.setContentType(text/html;charset=utf-8);PrintWriter out = response.getWriter();String um = request.getParameter(user);String up = request.getParameter(pass);String re = request.getParameter(remUser);User user = new User();user.setUsern

4、ame(um);user.setPassword(up);UserService UserService = new UserService();User uu = UserService.login(user);if (null != uu) out.print(歡迎: + uu.getUsername(); else out.print(賬戶密碼不匹配,請重新登錄); catch (Exception e) e.printStackTrace();4_實現(xiàn)UserService代碼public class UserService UserDao UserDao=new UserDao();

5、public User login(User user) throws SQLException return UserDao.login(user);5_實現(xiàn)UserDao代碼public User login(User user) throws SQLException String sql=select * from users where username= ? and password=?;QueryRunner qr=new QueryRunner(JDBCUtils.getDataSource(); Object params=user.getUsername(),user.ge

6、tPassword();return qr.query(sql, new BeanHandler(User.class),params); 6_在登錄成功的基礎(chǔ)上實現(xiàn)發(fā)送cookie代碼Cookie ck=new Cookie(username, um);if (null != re & yes.equals(re) ck.setMaxAge(60 * 60 * 24 * 365);ck.setPath(/day38_homework);elseck.setMaxAge(0);response.addCookie(ck);7_在ServletDemo02中判斷是否存在名稱為username的c

7、ookie來顯示不同的表單內(nèi)容.代碼如下:String str=;String str01=;Cookie ck = CookUtils.getCookieByName(username, request.getCookies();if(null=ck|.equals(ck)str=記住用戶名;str01=用戶;elseString username=ck.getValue();str=記住用戶名;str01=用戶;response.setContentType(text/html;charset=utf-8);PrintWriter out = response.getWriter();out.println();out.println(str01);out.println(密碼);out.println(str);out.println();out.println();CookUtils代碼如下:public class CookUtils public static Cookie getCookieByName(String name,Cook