本文主要是介绍Day21:实现退出功能、开发账号设置、检查登录状态,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
实现退出功能
- 将登录凭证修改为失效状态。
- 跳转至网站首页。
数据访问层
不用写了,已经有了updateStatus方法;
业务层
UserService
public void logout(String ticket) {loginTicketMapper.updateStatus(ticket, 1);}
Controller层
@RequestMapping(path = "/logout", method = RequestMethod.GET)
public String logout(@CookieValue("ticket") String ticket) {userService.logout(ticket);return "redirect:/login";
}
- 重定向默认是get请求
静态html修改index.html
<li class="nav-item ml-3 btn-group-vertical dropdown"><a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"><img src="http://images.nowcoder.com/head/1t.png" class="rounded-circle" style="width:30px;"/></a><div class="dropdown-menu" aria-labelledby="navbarDropdown"><a class="dropdown-item text-center" href="site/profile.html">个人主页</a><a class="dropdown-item text-center" href="site/setting.html">账号设置</a><a class="dropdown-item text-center" th:href="@{/logout}">退出登录</a><div class="dropdown-divider"></div><span class="dropdown-item text-center text-secondary">nowcoder</span></div>
</li>
把这里的退出登录改成th:href;
- 不明原因这里的下拉菜单没办法点开!!!先放个屁股,之后找到bug了再看。
显示登录信息
- 拦截器示例
- 定义拦截器,实现HandlerInterceptor
- 配置拦截器,为它指定拦截、排除的路径
- 拦截器应用
- 在请求开始时查询登录用户
- 在本次请求中持有用户数据
- 在模板视图上显示用户数据
- 在请求结束时清理用户数据
拦截器示例
- 拦截浏览器访问的请求,在请求开始/结束插入代码从而批量解决共有任务。
- 在controller中新建一个包Interceptor,新建AlphaInterceptor类:
@Controller
public class AlphaInterceptor implements HandlerInterceptor {
//在请求处理之前调用private static final Logger logger = LoggerFactory.getLogger(AlphaInterceptor.class);//返回值决定是否继续执行Controller中的方法@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {logger.debug("preHandle: " + handler.toString());return true;}//在请求处理之后调用@Overridepublic void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {System.out.println("postHandle: " + handler.toString());}//在模板引擎之后调用@Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {System.out.println("afterCompletion: " + handler.toString());}
}
- 需要实现HandlerInterceptor接口,但该接口中方法都是Default,不一定全部都需要重写。
- 编写一个配置类配置:
@Configuration
public class WebMvcConfig implements WebMvcConfigurer {@Autowired private AlphaInterceptor alphaInterceptor;public void addInterceptors(InterceptorRegistry registry) {//拦截除了css,js,png,jpg,jpeg之外的所有请求//只拦截注册和登录请求//为什么是/**/*:static目录下所有目录下的css,js,png,jpg,jpeg文件registry.addInterceptor(alphaInterceptor).excludePathPatterns("/**/*.css", "/**/*.js", "/**/*.png", "/**/*.jpg", "/**/*.jpeg").addPathPatterns("/register", "/login");}}
- 拦截除了css,js,png,jpg,jpeg之外的所有请求
- 只拦截register和login请求
- 为什么是/**/*:static目录下所有目录下的css,js,png,jpg,jpeg文件
- 测试
访问对应路径,看到以下输出:
拦截器应用
一次已登录的用户的请求过程(每次请求都有,故应该用拦截器进行复用)
- 首先封装一个util类获取对应key(ticket)的cookie:
public class CookieUtil {public static String getValue(HttpServletRequest request, String name){if(request == null || name == null){throw new IllegalArgumentException("参数为空");}Cookie[] cookies = request.getCookies();if(cookies != null){//一个cookie都没有for(Cookie cookie : cookies){if(cookie.getName().equals(name)){return cookie.getValue();}}}return null;}
}
- 为UserService添加通过ticket取user的方法:
public LoginTicket findLoginTicket(String ticket) {return loginTicketMapper.selectByTicket(ticket);}
- 编写LoginTicketInterceptor拦截器(见下)
- 编写HostHolder确保每个用户线程独立互不干扰:
@Component
public class HostHolder {private ThreadLocal<User> users = new ThreadLocal<>();public void setUser(User user) {users.set(user);}public User getUser() {return users.get();}public void clear() {users.remove();}}
在请求开始时查询登录用户
- 重写preHandler方法:
@Component
public class LoginTicketInterceptor implements HandlerInterceptor {@Autowiredprivate UserService userService;@Autowiredprivate HostHolder hostHolder;//重写preHandle方法@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {//从cookie中获取凭证String ticket = CookieUtil.getValue(request, "ticket");if(ticket != null) {//查询凭证LoginTicket loginTicket = userService.findLoginTicket(ticket);//检查凭证是否有效if(loginTicket != null && loginTicket.getStatus() == 0 && loginTicket.getExpired().after(new Date())) {//根据凭证查询用户User user = userService.findUserById(loginTicket.getUserId());//在本次请求中持有用户,把user暂存一下hostHolder.setUser(user);//hostHolder相当于为当前线程的user提供一个临时的容器}}return true;}
...
}
在本次请求中持有用户数据
hostHolder.setUser(user);
在模板视图上显示用户数据
- 重写PostHandler方法:
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {//获取用户User user = hostHolder.getUser();if(user != null && modelAndView != null) {modelAndView.addObject("loginUser", user);}
}
- modelAndView.addObject(“loginUser”, user);,在之后的模版中就可以使用loginUser了。
在请求结束时清理用户数据
- 重写afterCompletion方法:
@Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {//清除用户hostHolder.clear();}
- 修改html,使一些元素在未登录和登录时的显示情况不同:
<div class="collapse navbar-collapse" id="navbarSupportedContent"><ul class="navbar-nav mr-auto"><li class="nav-item ml-3 btn-group-vertical"><a class="nav-link" th:href="@{/index}">首页</a></li><li class="nav-item ml-3 btn-group-vertical" th:if="${loginUser!=null}"><a class="nav-link position-relative" href="site/letter.html">消息<span class="badge badge-danger">12</span></a></li><li class="nav-item ml-3 btn-group-vertical" th:if="${loginUser==null}"><a class="nav-link" th:href="@{/register}">注册</a></li><li class="nav-item ml-3 btn-group-vertical" th:if="${loginUser==null}"><a class="nav-link" th:href="@{/login}">登录</a></li><li class="nav-item ml-3 btn-group-vertical" th:if="${loginUser!=null}"><a class="nav-link" th:href="@{/logout}">退出</a></li><li class="nav-item ml-3 btn-group-vertical dropdown" th:if="${loginUser!=null}"><a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"><img th:src="${loginUser.headerUrl}" class="rounded-circle" style="width:30px;"/></a><div class="dropdown-menu" aria-labelledby="navbarDropdown"><a class="dropdown-item text-center" href="site/profile.html">个人主页</a><a class="dropdown-item text-center" href="site/setting.html">账号设置</a><a class="dropdown-item text-center" th:href="@{/logout}">退出登录</a><div class="dropdown-divider"></div><span class="dropdown-item text-center text-secondary" th:utext="${loginUser.username}">nowcoder</span></div></li></ul>
开发账号设置
请求:必须是POST请求
- 表单:enctype=“multipart/form-data”
- Spring MVC:通过 MultipartFile类上传文件。
访问账号设置页面
controller层
设置一个新的UserController:
@Controller
@RequestMapping("/user")
public class UserController {@RequestMapping(path = "/setting",method = RequestMethod.GET)public String getSettingPage() {return "/site/setting";}}
修改setting,html
- 除了静态改动态的必要设置外,
- 把index.html的链接练到/setting来。
<li class="nav-item ml-3 btn-group-vertical" th:if="${loginUser!=null}"><a class="nav-link" th:href="@{/user/setting}">账号设置</a>
</li>
上传头像
- 在配置文件中配置上传文件的存储路径
community.path.upload = /Users/iris/Desktop/community/upload
- 这里必须手动创建upload目录!否则之后上传的时候会不存在!
数据访问层
无。
业务层
- 更新headerUrl。
public int updateHeader(int userId, String headerUrl) {return userMapper.updateHeader(userId, headerUrl);
}
和Controller层
@RequestMapping(path = "/upload",method = RequestMethod.POST)public String uploadHeader(MultipartFile headerImage, Model model) {if(headerImage == null) {logger.error("上传文件为空");model.addAttribute("error","您还没有选择图片");return "/site/setting";}//不能直接上传到服务器的文件夹中,因为服务器可能有多个用户,文件名可能重复String fileName = headerImage.getOriginalFilename();//原始文件名String suffix = fileName.substring(fileName.lastIndexOf("."));//文件后缀if(suffix == null) {logger.error("文件格式不正确");return "redirect:/user/setting";}//生成随机文件名fileName = CommunityUtil.generateUUID() + suffix;//确定文件存放路径java.io.File dest = new java.io.File(uploadPath + "/" + fileName);try {headerImage.transferTo(dest);} catch (IOException e) {logger.error("上传文件失败" + e.getMessage());throw new RuntimeException("上传文件失败,服务器发生异常",e);}//更新当前用户的头像路径(web访问路径)//http://localhost:8080/community/user/header/xxx.pngUser user = hostHolder.getUser();String headerUrl = domain + contextPath + "/user/header/" + fileName;userService.updateHeader(user.getId(),headerUrl);return "redirect:/index";}
设置头像
真正的使用IO柳得到头像,这里注意为了解耦也在Controller里面写了:
@RequestMapping(path = "/header/{fileName}",method = RequestMethod.GET)public void getHeader(@PathVariable("fileName") String fileName, HttpServletResponse response) {//返回值是void:因为返回的是图片等二进制数据//服务器存放路径fileName = uploadPath + "/" + fileName;//文件后缀String suffix = fileName.substring(fileName.lastIndexOf("."));//响应图片response.setContentType("image/" + suffix);try(//放在try()中的流会自动关闭OutputStream os = response.getOutputStream();FileInputStream fis = new FileInputStream(fileName);) {byte[] buffer = new byte[1024];int b = 0;while((b = fis.read(buffer)) != -1) {os.write(buffer,0,b);}} catch (IOException e) {logger.error("读取头像失败" + e.getMessage());}}
- 返回值是void,因此返回的是图片等二进制数据;
- 放在try括号里的流会自动关闭,java8开始;
- 要用io写入二进制数据,建立缓冲区
- 使用PathVarible注解取filename的值赋给filename变量,从而填补@RequestMapping
修改静态setting.html为动态
<form class="mt-5" method="post" enctype="multipart/form-data" th:action="@{/user/upload}"><div class="form-group row mt-4"><label for="head-image" class="col-sm-2 col-form-label text-right">选择头像:</label><div class="col-sm-10"><div class="custom-file"><input type="file" th:class="${'custom-file-input ' + (error!= null ? 'is-invalid' : '')}"id="head-image" name="headerImage" lang="es" required=""><label class="custom-file-label" for="head-image" data-browse="文件">选择一张图片</label><div class="invalid-feedback" th:text="${error}">请选择一张图片!</div></div> </div></div><div class="form-group row mt-4"><div class="col-sm-2"></div><div class="col-sm-10 text-center"><button type="submit" class="btn btn-info text-white form-control">立即上传</button></div></div></form>
- 这个拼接字符串永远做不对!!!
修改密码
检查登录状态
- 目的:确保用户在未登录情况下不能通过特定的url访问界面。
使用拦截器
- 在方法前标注自定义注解
- 拦截所有请求,只处理带有该注解的方法
自定义注解(重要)
- 常用的元注解:
@Target、@Retention、@Document、@Inherited - 如何读取注解:
Method.getDeclaredAnnotations() Method.getAnnotation(Class annotationClass)
- 加注解就拦截,不加注解就不拦截。
- 新建一个包annotation,在其中创建一个注解LoginRequired,使用元注解修饰:
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface LoginRequired {//什么都不用写
}
- target表示该注解只能修饰method
- retention表示注解在runtime运行时也存在;
- 创建注解的拦截器:
@Component
public class LoginRequireInterceptor implements HandlerInterceptor {@Autowiredprivate HostHolder hostHolder;@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {if(handler instanceof HandlerMethod) {HandlerMethod handlerMethod = (HandlerMethod) handler;Method method = handlerMethod.getMethod();LoginRequired loginRequired = method.getAnnotation(LoginRequired.class);if(loginRequired != null && hostHolder.getUser() == null) {response.sendRedirect(request.getContextPath() + "/login");return false;}}return true;}
}
- HandlerMethod handlerMethod = (HandlerMethod) handler;传进来的handler是不是method;
- LoginRequired loginRequired = method.getAnnotation(LoginRequired.class);:判断注解是否存在,不在返回null;
- 判断如果注解存在,用户是否登录。
- 配置拦截器,不拦截css等文件节省资源:
public void addInterceptors(InterceptorRegistry registry) {//拦截除了css,js,png,jpg,jpeg之外的所有请求//只拦截注册和登录请求。。。registry.addInterceptor(loginRequireInterceptor).excludePathPatterns("/**/*.css", "/**/*.js", "/**/*.png", "/**/*.jpg", "/**/*.jpeg");}
- 给需要登录的页面加上@LoginRequired注解
@LoginRequired@RequestMapping(path = "/setting",method = RequestMethod.GET)public String getSettingPage() {return "/site/setting";}@LoginRequired@RequestMapping(path = "/upload",method = RequestMethod.POST)
public String uploadHeader(MultipartFile headerImage, Model model) {....}
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