JavaWeb使用Session和Cookie实现登录认证

public class LoginInterceptor implements HandlerInterceptor {  @Override  public void afterCompletion(HttpServletRequest request,                HttpServletResponse response, Object obj, Exception err)      throws Exception {  }  @Override  public void postHandle(HttpServletRequest request, HttpServletResponse response,              Object obj, ModelAndView mav) throws Exception {  }  @Override  public boolean preHandle(HttpServletRequest request, HttpServletResponse response,               Object obj) throws Exception {    //获取session里的登录状态值    String str = (String) request.getSession().getAttribute("isLogin");    //如果登录状态不为空则返回true，返回true则会执行相应controller的方法    if(str!=null){      return true;    }    //如果登录状态为空则重定向到登录页面，并返回false，不执行原来controller的方法    response.sendRedirect("/backend/loginPage");    return false;  }}

@Controller@RequestMapping("/backend")public class BackendController {  @RequestMapping(value = "/loginPage", method = {RequestMethod.GET})  public String loginPage(HttpServletRequest request,String account, String password){    return "login";  }  @RequestMapping(value = "/login", method = {RequestMethod.POST})  public String login(HttpServletRequest request,RedirectAttributes model, String account, String password){    //验证账号密码，如果符合则改变session里的状态，并重定向到主页    if ("jack".equals(account)&&"jack2017".equals(password)){      request.getSession().setAttribute("isLogin","yes");      return "redirect:IndexPage";    }else {      //密码错误则重定向回登录页，并返回错误，因为是重定向所要要用到RedirectAttributes      model.addFlashAttribute("error","密码错误");      return "redirect:loginPage";    }  }  //登出，移除登录状态并重定向的登录页  @RequestMapping(value = "/loginOut", method = {RequestMethod.GET})  public String loginOut(HttpServletRequest request) {    request.getSession().removeAttribute("isLogin");    return "redirect:loginPage";  }  @RequestMapping(value = "/IndexPage", method = {RequestMethod.GET})  public String IndexPage(HttpServletRequest request){    return "Index";  }}

  <!--省略其他基本配置-->  <!-- 配置拦截器 -->  <mvc:interceptors>    <!-- 配置登陆拦截器 -->    <mvc:interceptor>      <!--拦截后台页面的请求-->      <mvc:mapping path="/backend/**"/>      <!--不拦截登录页和登录的请求-->      <mvc:exclude-mapping path="/backend/loginPage"/>      <mvc:exclude-mapping path="/backend/login"/>      <bean class="com.ima.Interceptor.LoginInterceptor"></bean>    </mvc:interceptor>  </mvc:interceptors>

public class LoginInterceptor implements HandlerInterceptor {  @Override  public void afterCompletion(HttpServletRequest request,                HttpServletResponse response, Object obj, Exception err)      throws Exception {  }  @Override  public void postHandle(HttpServletRequest request, HttpServletResponse response,              Object obj, ModelAndView mav) throws Exception {  }  @Override  public boolean preHandle(HttpServletRequest request, HttpServletResponse response,               Object obj) throws Exception {//    获取request的cookie    Cookie[] cookies = request.getCookies();    if (null==cookies) {      System.out.println("没有cookie==============");    } else {//      遍历cookie如果找到登录状态则返回true执行原来controller的方法      for(Cookie cookie : cookies){        if(cookie.getName().equals("isLogin")){          return true;        }      }    }//    没有找到登录状态则重定向到登录页，返回false，不执行原来controller的方法    response.sendRedirect("/backend/loginPage");    return false;  }}

@Controller@RequestMapping("/backend")public class BackendController {  @RequestMapping(value = "/loginPage", method = {RequestMethod.GET})  public String loginPage(HttpServletRequest request, String account, String password) {    return "login";  }  @RequestMapping(value = "/login", method = {RequestMethod.POST})  public String login(HttpServletRequest request, HttpServletResponse response, RedirectAttributes model, String account, String password) {    if ("edehou".equals(account) && "aidou2017".equals(password)) {      Cookie cookie = new Cookie("isLogin", "yes");      cookie.setMaxAge(30 * 60);// 设置为30min      cookie.setPath("/");      response.addCookie(cookie);      return "redirect:IndexPage";    } else {      model.addFlashAttribute("error", "密码错误");      return "redirect:loginPage";    }  }  @RequestMapping(value = "/logOut", method = {RequestMethod.GET})  public String loginOut(HttpServletRequest request, HttpServletResponse response) {    Cookie[] cookies = request.getCookies();    for (Cookie cookie : cookies) {      if (cookie.getName().equals("isLogin")) {        cookie.setValue(null);        cookie.setMaxAge(0);// 立即销毁cookie        cookie.setPath("/");        response.addCookie(cookie);        break;      }    }    return "redirect:loginPage";  }  @RequestMapping(value = "/IndexPage", method = {RequestMethod.GET})  public String IndexPage(HttpServletRequest request) {    return "Index";  }}