仿牛客社区项目（第四章）（总）

布满荆棘的人生 2023-09-27 10:41 45阅读 0赞

#### 文章目录 ####

*  第三章：Redis，一站式高性能存储方案
 *  一、Redis入门
 *  二、Spring整合Redis
 *   *  1. config包
     *  2. 修改配置文件
     *  3. 测试类
 *  三、点赞
 *   *  1. util包
     *  2. service包
     *  2. controller层
     *  4. View层
     *  5. 功能测试
 *  四、我收到的赞
 *   *  1. util包
     *  2. servic层
     *  3. controller层
     *  4. View层
     *  5. 功能测试
 *  五、关注、取消关注
 *   *  1. util包
     *  2. service包
     *  3. controller包
     *  4. view层
     *  5. 功能测试
 *  六、关注列表、粉丝列表
 *   *  1. service层
     *  2. controller层
     *  3. view层
     *  4. 功能测试
 *  七、优化登录模块
 *   *  1. util包
     *  2. dao层
     *  3. service层
     *  4. controller层
     *  5. 功能测试

## 第三章：Redis，一站式高性能存储方案 ##

## 一、Redis入门 ##

*  `Redis` 是一款基于键值对的`NoSQL`数据库，它的值支持多种数据结构：字符串(`strings`)、哈希(`hashes`)、列表(`lists`)、集合(`sets`)、有序集合(`sorted sets`)等。
 *  `Redis`将所有的数据都存放在内存中，所以它的读写性能十分惊人。同时，`Redis`还可以将内存中的数据以快照或日志的形式保存到硬盘上，以保证数据的安全性。
 *  `Redis`典型的应用场景包括：缓存、排行榜、计数器、社交网络、消息队列等。

## 二、Spring整合Redis ##

*  引入依赖
    
     *  `spring-boot-starter-data-redis`
 *  配置Redis
    
     *  配置数据库参数
     *  编写配置类，构造 `RedisTemplate`
 *  访问Redis
    
     *  `redisTemplate.opsForValue()`
     *  `redisTemplate.opsForHash()`
     *  `redisTemplate.opsForList()`
     *  `redisTemplate.opsForSet()`
     *  `redisTemplate.opsForZSet()`

### 1. config包 ###

在 `config` 包中创建 `RedisConfig` 类，代码如下：

@Configuration
    public class RedisConfig {
    
        @Bean
        public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
            RedisTemplate<String, Object> template = new RedisTemplate<>();
            template.setConnectionFactory(factory);
    
            // 设置key的序列化方式
            template.setKeySerializer(RedisSerializer.string());
    
            // 设置value的序列化方式
            template.setValueSerializer(RedisSerializer.json());
    
            // 设置hash的key序列化方式
            template.setHashKeySerializer(RedisSerializer.string());
    
            // 设置hash的value序列化方式
            template.setHashValueSerializer(RedisSerializer.json());
    
            template.afterPropertiesSet();;
            return template;
        }
    }

### 2. 修改配置文件 ###

在 `application.properties` 中添加配置信息：

#RedisProperties
    spring.redis.database=11
    spring.redis.host=localhost
    spring.redis.port=6379

### 3. 测试类 ###

添加 `RedisTests` 测试类，各种测试的代码如下：

@SpringBootTest
    @ContextConfiguration(classes = CommunityApplication.class)
    public class RedisTests {
    
        @Autowired
        private RedisTemplate redisTemplate;
    
        @Test
        public void testStrings() {
            String redisKey = "test:count";
    
            System.out.println("result:");
            redisTemplate.opsForValue().set(redisKey, 1);
    
            System.out.println(redisTemplate.opsForValue().get(redisKey));
            System.out.println(redisTemplate.opsForValue().increment(redisKey));
            System.out.println(redisTemplate.opsForValue().decrement(redisKey));
        }
    
    
        @Test
        public void testHashes() {
            String redisKey = "test:user";
    
            redisTemplate.opsForHash().put(redisKey, "id", 1);
            redisTemplate.opsForHash().put(redisKey, "username", "zhangsan");
    
            System.out.println(redisTemplate.opsForHash().get(redisKey, "id"));
            System.out.println(redisTemplate.opsForHash().get(redisKey, "username"));
        }
    
        @Test
        public void testLists() {
            String redisKey = "test:ids";
    
            redisTemplate.opsForList().leftPush(redisKey, 101);
            redisTemplate.opsForList().leftPush(redisKey, 102);
            redisTemplate.opsForList().leftPush(redisKey, 103);
    
            System.out.println(redisTemplate.opsForList().size(redisKey));
            System.out.println(redisTemplate.opsForList().index(redisKey, 0));
            System.out.println(redisTemplate.opsForList().range(redisKey,0, 2));
    
            System.out.println(redisTemplate.opsForList().leftPop(redisKey));
            System.out.println(redisTemplate.opsForList().leftPop(redisKey));
            System.out.println(redisTemplate.opsForList().leftPop(redisKey));
        }
    
        @Test
        public void testSet() {
            String redisKey = "test:teacher";
    
            redisTemplate.opsForSet().add(redisKey,"张三", "李四", "王五", "赵六");
    
            System.out.println(redisTemplate.opsForSet().size(redisKey));
            System.out.println(redisTemplate.opsForSet().pop(redisKey));
            System.out.println(redisTemplate.opsForSet().members(redisKey));
        }
    
        @Test
        public void testSortedSet() {
            String redisKey = "test:students";
    
            redisTemplate.opsForZSet().add(redisKey, "张三", 10);
            redisTemplate.opsForZSet().add(redisKey, "李四", 20);
            redisTemplate.opsForZSet().add(redisKey, "王五", 40);
            redisTemplate.opsForZSet().add(redisKey, "赵六", 30);
    
            System.out.println(redisTemplate.opsForZSet().zCard(redisKey));
            System.out.println(redisTemplate.opsForZSet().score(redisKey,"张三"));
            System.out.println(redisTemplate.opsForZSet().reverseRank(redisKey,"张三"));
            System.out.println(redisTemplate.opsForZSet().reverseRange(redisKey,0, 2));
        }
    
        @Test
        public void testKeys() {
            redisTemplate.delete("test:user");
    
            System.out.println(redisTemplate.hasKey("test:user"));
    
           redisTemplate.expire("test:students", 10, TimeUnit.SECONDS);
        }
    
        // 多次访问同一个key
        @Test
        public void testBoundOperations() {
            String redisKey = "test:count";
            BoundValueOperations operations = redisTemplate.boundValueOps(redisKey);
            operations.increment();
            operations.increment();
            operations.increment();
            operations.increment();
            operations.increment();
            operations.increment();
            System.out.println(operations.get());
        }
    
        // 编程式事务
        @Test
        public void testTransactional() {
            Object obj = redisTemplate.execute(new SessionCallback() {
                @Override
                public Object execute(RedisOperations operations) throws DataAccessException {
                    String redisKey = "test:tx";
    
                    operations.multi();
    
                    operations.opsForSet().add(redisKey, "aa");
                    operations.opsForSet().add(redisKey, "bb");
                    operations.opsForSet().add(redisKey, "cc");
    
                    return operations.exec();
                }
            });
            System.out.println(obj);
        }
    }

## 三、点赞 ##

*  点赞
    
     *  支持对帖子、评论点赞。
     *  第1次点赞，第2次取消点赞。
 *  首页点赞数量
    
     *  统计帖子的点赞数量。
 *  详情页面点赞数量
    
     *  统计点赞数量。
     *  显示点赞状态。

### 1. util包 ###

在 `util` 包下创建 `RedisKeyUtil` 类，代码如下：

public class RedisKeyUtil {
    
        public static final String SPLIT = ":";
    
        private static final String PREFIX_ENTITY_LIKE = "like:entity";
    
        // 某个实体的赞
        // like:entity:entityType:entityId -> set(userId)
        public static String getEntityLikeKey(int entityType, int entityId) {
            return PREFIX_ENTITY_LIKE + SPLIT + entityType + SPLIT + entityId;
        }
    }

### 2. service包 ###

创建 `LikeService` 类，代码如下：

@Service
    public class LikeService {
    
        @Autowired
        private RedisTemplate redisTemplate;
    
        // 点赞
        public void like(int userId, int entityType, int entityId) {
    
            String entityLikeKey = RedisKeyUtil.getEntityLikeKey(entityType, entityId);
            Boolean ismember = redisTemplate.opsForSet().isMember(entityLikeKey, userId);
            if (ismember) {
                redisTemplate.opsForSet().remove(entityLikeKey, userId);
            } else {
                redisTemplate.opsForSet().add(entityLikeKey, userId);
            }
        }
    
        // 查询某实体点赞的数量
        public long findEntityLikeCount(int entityType, int entityId) {
            String entityLikeKey = RedisKeyUtil.getEntityLikeKey(entityType, entityId);
            return redisTemplate.opsForSet().size(entityLikeKey);
        }
    
        // 查询某人对某实体的点赞状态
        public int findEntityLikeStatus(int userId, int entityType, int entityId) {
            String entityLikeKey = RedisKeyUtil.getEntityLikeKey(entityType, entityId);
            return redisTemplate.opsForSet().isMember(entityLikeKey, userId) ? 1 : 0;
        }
    }

### 2. controller层 ###

创建 `LikeController` 层，代码如下：

@Controller
    public class LikeController {
    
        @Autowired
        private LikeService likeService;
    
        @Autowired
        HostHolder hostHolder;
    
    
        @RequestMapping(value = "/like", method = RequestMethod.POST)
        @ResponseBody
        public String like(int entityType, int entityId) {
            User user = hostHolder.getUser();
    
            // 点赞zzz
            likeService.like(user.getId(), entityType, entityId);
    
            // 数量
            long likeCount = likeService.findEntityLikeCount(entityType, entityId);
    
            // 状态
            int likeStatus = likeService.findEntityLikeStatus(user.getId(), entityType, entityId);
    
            // 返回的结果
            Map<String, Object> map = new HashMap<>();
            map.put("likeCount", likeCount);
            map.put("likeStatus", likeStatus);
    
            return CommunityUtil.getJSONString(0, null, map);
        }
    }

在 `DiscussPostController` 和 `HomeController` 类中添加查询点赞数量和点赞状态的方法，代码如下：

@Controller
    @RequestMapping("/discuss")
    public class DiscussPostController implements CommunityConstant {
    
        @Autowired
        private DiscussPostService discussPostService;
    
        @Autowired
        private HostHolder hostHolder;
    
        @Autowired
        private UserService userService;
    
        @Autowired
        private CommentService commentService;
    
    
        @Autowired
        private LikeService likeService;
    
        @RequestMapping(path = "/add", method = RequestMethod.POST)
        @ResponseBody
        public String addDiscussPost(String title, String content) {
            User user = hostHolder.getUser();
            if (user == null) {
                return CommunityUtil.getJSONString(403,"你还没有登录哦！");
            }
    
            DiscussPost post = new DiscussPost();
            post.setUserId(user.getId());
            post.setTitle(title);
            post.setContent(content);
            post.setCreateTime(new Date());
            discussPostService.addDiscussPost(post);
    
            // 报错的情况，会统一处理
            return CommunityUtil.getJSONString(0, "发布成功!");
        }
    
        @RequestMapping(path = "/detail/{discussPostId}", method = RequestMethod.GET)
        public String getDiscussPost(@PathVariable("discussPostId") int discussPostId, Model model, Page page) {
            // 帖子
            DiscussPost post = discussPostService.findDiscussPostById(discussPostId);
            model.addAttribute("post", post);
    
            // 作者
            User user = userService.findUserById(post.getUserId());
            model.addAttribute("user", user);
    
            // 点赞数量
            long likeCount = likeService.findEntityLikeCount(ENTITY_TYPE_POST, discussPostId);
            model.addAttribute("likeCount", likeCount);
    
            // 点赞状态
            int likeStatus = hostHolder.getUser() == null ? 0 :
                    likeService.findEntityLikeStatus(hostHolder.getUser().getId(), ENTITY_TYPE_POST, discussPostId);
            model.addAttribute("likeStatus", likeStatus);
    
            // 评论分页信息
            page.setLimit(5);
            page.setPath("/discuss/detail/" + discussPostId);
            page.setRows(post.getCommentCount());
    
            // 评论: 给帖子的评论
            // 回复: 给评论的评论
            // 评论列表
            List<Comment> commentList = commentService.findCommentsByEntity(
                    ENTITY_TYPE_POST, post.getId(), page.getOffset(), page.getLimit());
            // 评论VO列表
            List<Map<String, Object>> commentVoList = new ArrayList<>();
            if (commentList != null) {
                for (Comment comment : commentList) {
    
                    // 评论VO
                    Map<String, Object> commentVo = new HashMap<>();
                    // 评论
                    commentVo.put("comment", comment);
                    // 查询到评论的作者
                    commentVo.put("user", userService.findUserById(comment.getUserId()));
    
                    // 点赞数量
                    likeCount = likeService.findEntityLikeCount(ENTITY_TYPE_COMMENT, comment.getId());
                    commentVo.put("likeCount", likeCount);
    
                    // 点赞状态
                     likeStatus = hostHolder.getUser() == null ? 0 :
                            likeService.findEntityLikeStatus(hostHolder.getUser().getId(), ENTITY_TYPE_COMMENT, comment.getId());
                    commentVo.put("likeStatus", likeStatus);
    
                    // 回复列表
                    List<Comment> replyList = commentService.findCommentsByEntity(
                            ENTITY_TYPE_COMMENT, comment.getId(), 0, Integer.MAX_VALUE);
                    // 回复VO列表
                    List<Map<String, Object>> replyVoList = new ArrayList<>();
                    if (replyList != null) {
                        for (Comment reply : replyList) {
                            Map<String, Object> replyVo = new HashMap<>();
                            // 回复
                            replyVo.put("reply", reply);
                            // 作者
                            replyVo.put("user", userService.findUserById(reply.getUserId()));
                            // 回复目标
                            User target = reply.getTargetId() == 0 ? null : userService.findUserById(reply.getTargetId());
                            replyVo.put("target", target);
    
                            // 点赞数量
                            likeCount = likeService.findEntityLikeCount(ENTITY_TYPE_COMMENT, reply.getId());
                            replyVo.put("likeCount", likeCount);
    
                            // 点赞状态
                            likeStatus = hostHolder.getUser() == null ? 0 :
                                    likeService.findEntityLikeStatus(hostHolder.getUser().getId(), ENTITY_TYPE_COMMENT, reply.getId());
                            replyVo.put("likeStatus", likeStatus);
    
                            replyVoList.add(replyVo);
                        }
                    }
                    commentVo.put("replys", replyVoList);
    
                    // 回复数量
                    int replyCount = commentService.findCommentCount(ENTITY_TYPE_COMMENT, comment.getId());
                    commentVo.put("replyCount", replyCount);
    
                    commentVoList.add(commentVo);
                }
            }
    
            model.addAttribute("comments", commentVoList);
    
            return "/site/discuss-detail";
        }
    
    }

@Controller
    public class HomeController implements CommunityConstant {
    
        @Autowired
        private DiscussPostService discussPostService;
    
        @Autowired
        private UserService userService;
    
        @Autowired
        private LikeService likeService;
    
        @RequestMapping(path = "/index", method = RequestMethod.GET)
        public String getIndexPage(Model model, Page page) {
            // 方法调用时，SpringMVC会自动实例化Model和Page。并将Page注入到Model
            // 所以，在thymeleaf中可以直接访问page对象中的数据
            page.setRows(discussPostService.findDiscussPostRows(0));
            page.setPath("/index");
    
            List<DiscussPost> list = discussPostService.findDiscussPosts(0, page.getOffset(), page.getLimit());
            List<Map<String, Object>> discussPosts = new ArrayList<>();
            if (list != null) {
                for (DiscussPost post : list) {
                    Map<String, Object> map = new HashMap<>();
                    map.put("post", post);
                    User user = userService.findUserById(post.getUserId());
                    map.put("user", user);
    
                    long likeCount = likeService.findEntityLikeCount(ENTITY_TYPE_POST, post.getId());
                    map.put("likeCount", likeCount);
    
                    discussPosts.add(map);
    
                }
            }
    
            model.addAttribute("discussPosts", discussPosts);
            return "/index";
        }
    
        @RequestMapping(path = "/error", method = RequestMethod.GET)
        public String getErrorPage() {
            return "/error/500";
    
        }
    }

### 4. View层 ###

首页和帖子详情页的代码修改在汇总中进行查看。

`discuss.js`：

### 5. 功能测试 ###

![在这里插入图片描述][9ebe457b769c410684ba037924162c6a.png]  
![在这里插入图片描述][42667fcc551644e08ac6ad784cf2587a.png]  
![在这里插入图片描述][557e345044b844769cab162c8df03633.png]

## 四、我收到的赞 ##

*  重构点赞功能
    
     *  以用户为 `key`,记录点赞数量
     *  `increment(key)`，`decrement(key)`
 *  开发个人主页
    
     *  以用户为 `key`， 查询点赞数量

### 1. util包 ###

在 `RedisKeyUtil` 中添加 `getUserLikeKey` 方法：

*/
    public class RedisKeyUtil {
    
        public static final String SPLIT = ":";
    
        private static final String PREFIX_ENTITY_LIKE = "like:entity";
    
        private static final String PREFIX_USER_LIKE = "like:user";
    
        // 某个实体的赞
        // like:entity:entityType:entityId -> set(userId)
        public static String getEntityLikeKey(int entityType, int entityId) {
            return PREFIX_ENTITY_LIKE + SPLIT + entityType + SPLIT + entityId;
        }
    
        // 某个用户的赞
        //like:user: userId->int
        public static String getUserLikeKey(int userId) {
            return PREFIX_USER_LIKE + SPLIT + userId;
        }
    }

### 2. servic层 ###

在 `LikeService` 中对 `like` 方法进行重载，并且添加 `findUserLikeCount` 方法，代码如下：

@Service
    public class LikeService {
    
        @Autowired
        private RedisTemplate redisTemplate;
    
        // 点赞
        public void like(int userId, int entityType, int entityId, int entityUserId) {
            redisTemplate.execute(new SessionCallback() {
                @Override
                public Object execute(RedisOperations operations) throws DataAccessException {
                    String entityLikeKey = RedisKeyUtil.getEntityLikeKey(entityType, entityId);
                    String userLikeKey = RedisKeyUtil.getUserLikeKey(entityUserId);
    
                    boolean isMember = operations.opsForSet().isMember(entityLikeKey, userId);
    
                    operations.multi();
    
                    if (isMember) {
                        operations.opsForSet().remove(entityLikeKey, userId);
                        operations.opsForValue().decrement(userLikeKey);
                    } else {
                        operations.opsForSet().add(entityLikeKey, userId);
                        operations.opsForValue().increment(userLikeKey);
                    }
    
                    return operations.exec();
                }
            });
        }
    
    
        // 查询某实体点赞的数量
        public long findEntityLikeCount(int entityType, int entityId) {
            String entityLikeKey = RedisKeyUtil.getEntityLikeKey(entityType, entityId);
            return redisTemplate.opsForSet().size(entityLikeKey);
        }
    
        // 查询某人对某实体的点赞状态
        public int findEntityLikeStatus(int userId, int entityType, int entityId) {
            String entityLikeKey = RedisKeyUtil.getEntityLikeKey(entityType, entityId);
            return redisTemplate.opsForSet().isMember(entityLikeKey, userId) ? 1 : 0;
        }
    
        // 查询某个用户获得的赞
        public int findUserLikeCount(int userId) {
            String userLikeKey = RedisKeyUtil.getUserLikeKey(userId);
            Integer count = (Integer) redisTemplate.opsForValue().get(userLikeKey);
            return count == null ? 0 : count.intValue();
        }
    }

### 3. controller层 ###

`LikeController` 类中对 `like` 方法进行重构，代码如下：

@Controller
    public class LikeController {
    
        @Autowired
        private LikeService likeService;
    
        @Autowired
        private HostHolder hostHolder;
    
        @RequestMapping(path = "/like", method = RequestMethod.POST)
        @ResponseBody
        public String like(int entityType, int entityId, int entityUserId) {
            User user = hostHolder.getUser();
    
            // 点赞
            likeService.like(user.getId(), entityType, entityId, entityUserId);
    
            // 数量
            long likeCount = likeService.findEntityLikeCount(entityType, entityId);
            // 状态
            int likeStatus = likeService.findEntityLikeStatus(user.getId(), entityType, entityId);
            // 返回的结果
            Map<String, Object> map = new HashMap<>();
            map.put("likeCount", likeCount);
            map.put("likeStatus", likeStatus);
    
            return CommunityUtil.getJSONString(0, null, map);
        }
    }

`UserController` 中添加 `getProfilePage` 方法，代码如下：

@Controller
    @RequestMapping("/user")
    public class UserController {
    
        private static final Logger logger = LoggerFactory.getLogger(AlphaInterceptor.class);
    
        @Value("${community.path.upload}")
        private String uploadPath;
    
        @Value("${community.path.domain}")
        private String domain;
    
        @Value("${server.servlet.context-path}")
        private String contextPath;
    
        @Autowired
        private UserService userService;
    
        @Autowired
        private HostHolder hostHolder;
    
        @Autowired
        private LikeService likeService;
    
        @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) {
            if (headerImage == null) {
                model.addAttribute("error", "您还没有选择图片！");
                return "/site/setting";
            }
    
            String fileName = headerImage.getOriginalFilename();
            String suffix = fileName.substring(fileName.lastIndexOf("."));
            if (StringUtils.isBlank(suffix)) {
                model.addAttribute("error", "文件的格式不正确!");
                return "/site/setting";
            }
    
            // 生成随机文件名
            fileName = CommunityUtil.generateUUID() + suffix;
            // 确定文件存放的路径
            File dest = new File(uploadPath + "/" + fileName);
            // 存储文件
            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);
            }
    
            // 更新当前用户头像的路径
            User user = hostHolder.getUser();
            String headerUrl = domain + contextPath + "/user/header/" + fileName;
            userService.updateHeader(user.getId(), headerUrl);
    
    
            return "redirect:/index";
        }
    
    
        //暴露一个访问接口给外部
        @RequestMapping(path = "/header/{fileName}", method = RequestMethod.GET)
        public void getHeader(@PathVariable("fileName") String fileName, HttpServletResponse response) {
            // 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 (
                    FileInputStream fis = new FileInputStream(fileName);
                    OutputStream os = response.getOutputStream();
            ) {
                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());
            }
        }
    
        // 个人主页
        @RequestMapping(path = "/profile/{userId}", method = RequestMethod.GET)
        public String getProfilePage(@PathVariable("userId") int userId, Model model) {
            User user = userService.findUserById(userId);
            if (user == null) {
                throw new RuntimeException("该用户不存在！");
            }
    
            // 用户
            model.addAttribute("user", user);
            // 点赞数量
            int likeCount = likeService.findUserLikeCount(userId);
            model.addAttribute("likeCount", likeCount);
    
            return "/site/profile";
        }
    }

### 4. View层 ###

首页、帖子详情页和个人主页的代码修改在汇总中进行查看。  
`discuss-detail.js`：

### 5. 功能测试 ###

![在这里插入图片描述][bfde94f9565c40d2b6ddba80510e6867.png]  
![在这里插入图片描述][296041d2812f4b4994490d37a3d37bef.png]  
![在这里插入图片描述][76e0936296d747858462054502adee6d.png]  
  
查看 `redis` 数据库：  
![在这里插入图片描述][06709912ac6a4befa453297f95872275.png]

## 五、关注、取消关注 ##

*  需求
    
     *  开发关注、取消关注功能。
     *  统计用户的关注数、粉丝数。
 *  关键
    
     *  若 `A` 关注了 `B`，则 `A` 是 `B` 的 `Follower`(粉丝)， `B` 是 `A` 的 `Followee`(目标)
     *  关注的目标可以是用户、帖子、题目等，在实现时将这些目标抽象为实体。

### 1. util包 ###

在 `RedisKeyUtil` 类中添加 `getFollowerKey` 方法，代码如下：

### 2. service包 ###

添加 `FollowerService` 类，代码如下：

@Service
    public class FollowService {
    
        @Autowired
        private RedisTemplate redisTemplate;
    
        public void follow(int userId, int entityType, int entityId) {
            redisTemplate.execute(new SessionCallback() {
                @Override
                public Object execute(RedisOperations operations) throws DataAccessException {
                    String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
                    String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);
    
                    operations.multi();
    
                    operations.opsForZSet().add(followeeKey, entityId, System.currentTimeMillis());
                    operations.opsForZSet().add(followerKey, userId, System.currentTimeMillis());
    
                    return operations.exec();
                }
            });
        }
    
        public void unfollow(int userId, int entityType, int entityId) {
            redisTemplate.execute(new SessionCallback() {
                @Override
                public Object execute(RedisOperations operations) throws DataAccessException {
                    String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
                    String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);
    
                    operations.multi();
    
                    operations.opsForZSet().remove(followeeKey, entityId);
                    operations.opsForZSet().remove(followerKey, userId);
    
                    return operations.exec();
                }
            });
        }
    
        // 查询关注的实体的数量
        public long findFolloweeCount(int userId, int entityType) {
            String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
            return redisTemplate.opsForZSet().zCard(followeeKey);
        }
    
        //  查询实体的粉丝数量
        public long findFollowerCount(int entityType, int entityId) {
            String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);
            return redisTemplate.opsForZSet().zCard(followerKey);
        }
    
    
        // 查询当前用户是否已关注实体  用户关注的实体
        public boolean hasFollowed(int userId, int entityType, int entityId) {
            String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
            return redisTemplate.opsForZSet().score(followeeKey, entityId) != null;
        }
    
    }

### 3. controller包 ###

添加 `FolloweController` 类，代码如下：

@Controller
    public class FollowController {
    
        @Autowired
        private FollowService followService;
    
        @Autowired
        private HostHolder hostHolder;
    
        @RequestMapping(path = "/follow", method = RequestMethod.POST)
        @ResponseBody
        public String follow(int entityType, int entityId) {
            User user = hostHolder.getUser();
    
            followService.follow(user.getId(), entityType, entityId);
    
            return CommunityUtil.getJSONString(0, "已关注！");
        }
    
        @RequestMapping(path = "/unfollow", method = RequestMethod.POST)
        @ResponseBody
        public String unfollow(int entityType, int entityId) {
            User user = hostHolder.getUser();
    
            followService.unfollow(user.getId(), entityType, entityId);
    
            return CommunityUtil.getJSONString(0, "已取消关注!");
        }
    }

在 `UserController` 对 `getProfilePage` 方法进行重构， 代码如下：  
用户在 `index` 页面访问 `profile` 页面时，先获取查看用户信息的该用户实体，接着查询`redis`数据库，调用`likeService`查询点赞数量，调用`followService`查询关注数量和粉丝数量，是否已关注作者，并返回至`profile`页面。

@Controller
    @RequestMapping("/user")
    public class UserController implements CommunityConstant {
    
        private static final Logger logger = LoggerFactory.getLogger(AlphaInterceptor.class);
    
        @Value("${community.path.upload}")
        private String uploadPath;
    
        @Value("${community.path.domain}")
        private String domain;
    
        @Value("${server.servlet.context-path}")
        private String contextPath;
    
        @Autowired
        private UserService userService;
    
        @Autowired
        private HostHolder hostHolder;
    
        @Autowired
        private LikeService likeService;
    
        @Autowired
        private FollowService followService;
    
        @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) {
            if (headerImage == null) {
                model.addAttribute("error", "您还没有选择图片！");
                return "/site/setting";
            }
    
            String fileName = headerImage.getOriginalFilename();
            String suffix = fileName.substring(fileName.lastIndexOf("."));
            if (StringUtils.isBlank(suffix)) {
                model.addAttribute("error", "文件的格式不正确!");
                return "/site/setting";
            }
    
            // 生成随机文件名
            fileName = CommunityUtil.generateUUID() + suffix;
            // 确定文件存放的路径
            File dest = new File(uploadPath + "/" + fileName);
            // 存储文件
            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);
            }
    
            // 更新当前用户头像的路径
            User user = hostHolder.getUser();
            String headerUrl = domain + contextPath + "/user/header/" + fileName;
            userService.updateHeader(user.getId(), headerUrl);
    
    
            return "redirect:/index";
        }
    
    
        //暴露一个访问接口给外部
        @RequestMapping(path = "/header/{fileName}", method = RequestMethod.GET)
        public void getHeader(@PathVariable("fileName") String fileName, HttpServletResponse response) {
            // 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 (
                    FileInputStream fis = new FileInputStream(fileName);
                    OutputStream os = response.getOutputStream();
            ) {
                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());
            }
        }
    
        // 个人主页
        @RequestMapping(path = "/profile/{userId}", method = RequestMethod.GET)
        public String getProfilePage(@PathVariable("userId") int userId, Model model) {
            User user = userService.findUserById(userId);
            if (user == null) {
                throw new RuntimeException("该用户不存在！");
            }
    
            // 用户
            model.addAttribute("user", user);
    
            // 点赞数量
            int likeCount = likeService.findUserLikeCount(userId);
            model.addAttribute("likeCount", likeCount);
    
            // 关注数量
            long followeeCount = followService.findFolloweeCount(userId, ENTITY_TYPE_USER);
            model.addAttribute("followeeCount", followeeCount);
    
            // 粉丝数量
            long followerCount = followService.findFollowerCount(ENTITY_TYPE_USER, userId);
            model.addAttribute("followerCount", followerCount);
    
            // 是否已关注
            boolean hasFollowed = false;
            if (hostHolder.getUser() != null) {
                hasFollowed = followService.hasFollowed(hostHolder.getUser().getId(), ENTITY_TYPE_USER, userId);
            }
            model.addAttribute("hasFollowed", hasFollowed);
    
    
            return "/site/profile";
        }
    }

### 4. view层 ###

`profile.index`：

<div class="media mt-5">
    					<img th:src="${user.headerUrl}" class="align-self-start mr-4 rounded-circle" alt="用户头像" style="width:50px;">
    					<div class="media-body">
    						<h5 class="mt-0 text-warning">
    							<span th:utext="${user.username}">nowcoder</span>
    							<input type="hidden" id="entityId" th:value="${user.id}">
    							<button type="button" th:class="|btn ${hasFollowed?'btn-secondary':'btn-info'} btn-sm float-right mr-5 follow-btn|"
    									th:text="${hasFollowed?'已关注':'关注TA'}" th:if="${loginUser!=null&&loginUser.id!=user.id}">关注TA</button>
    						</h5>
    						<div class="text-muted mt-3">
    							<span>注册于 <i class="text-muted" th:text="${#dates.format(user.createTime,'yyyy-MM-dd HH:mm:ss')}">2015-06-12 15:20:12</i></span>
    						</div>
    						<div class="text-muted mt-3 mb-5">
    							<span>关注了 <a class="text-primary" href="followee.html" th:text="${followeeCount}">5</a> 人</span>
    							<span class="ml-4">关注者 <a class="text-primary" href="follower.html" th:text="${followerCount}">123</a> 人</span>
    							<span class="ml-4">获得了 <i class="text-danger" th:text="${likeCount}">87</i> 个赞</span>
    						</div>
    					</div>
    				</div>

`profile.js`：

$(function(){
        $(".follow-btn").click(follow);
    });
    
    function follow() {
        var btn = this;
        if($(btn).hasClass("btn-info")) {
            // 关注TA
            $.post(
                CONTEXT_PATH + "/follow",
                {"entityType":3,"entityId":$(btn).prev().val()},
                function(data) {
                    data = $.parseJSON(data);
                    if(data.code == 0) {
                        window.location.reload();
                    } else {
                        alert(data.msg);
                    }
                }
            );
            // $(btn).text("已关注").removeClass("btn-info").addClass("btn-secondary");
        } else {
            // 取消关注
            $.post(
                CONTEXT_PATH + "/unfollow",
                {"entityType":3,"entityId":$(btn).prev().val()},
                function(data) {
                    data = $.parseJSON(data);
                    if(data.code == 0) {
                        window.location.reload();
                    } else {
                        alert(data.msg);
                    }
                }
            );
            //$(btn).text("关注TA").removeClass("btn-secondary").addClass("btn-info");
        }
    }

### 5. 功能测试 ###

![在这里插入图片描述][af8f8befc0e74671befa9d3b22382528.png]  
![在这里插入图片描述][785eeb7419f841c4a61f128adeae27d9.png]

![f0878004f3434b5fb29f05878117a2b1.png][]

## 六、关注列表、粉丝列表 ##

*  业务层
    
     *  查询某个用户关注的人，支持分页。
     *  查询某个用户的粉丝，支持分页。
 *  表现层
    
     *  处理“查询关注的人”、“查询粉丝”请求。
     *  编写“查询关注的人”、“查询粉丝”模板。

### 1. service层 ###

在 `FollowerService` 类中添加 `findFollowees` 和 `findFollowers` 方法，代码如下：

@Service
    public class FollowService implements CommunityConstant {
    
        @Autowired
        private RedisTemplate redisTemplate;
    
        @Autowired
        private UserService userService;
    
        public void follow(int userId, int entityType, int entityId) {
            redisTemplate.execute(new SessionCallback() {
                @Override
                public Object execute(RedisOperations operations) throws DataAccessException {
                    String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
                    String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);
    
                    operations.multi();
    
                    operations.opsForZSet().add(followeeKey, entityId, System.currentTimeMillis());
                    operations.opsForZSet().add(followerKey, userId, System.currentTimeMillis());
    
                    return operations.exec();
                }
            });
        }
    
        public void unfollow(int userId, int entityType, int entityId) {
            redisTemplate.execute(new SessionCallback() {
                @Override
                public Object execute(RedisOperations operations) throws DataAccessException {
                    String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
                    String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);
    
                    operations.multi();
    
                    operations.opsForZSet().remove(followeeKey, entityId);
                    operations.opsForZSet().remove(followerKey, userId);
    
                    return operations.exec();
                }
            });
        }
    
        // 查询关注的实体的数量
        public long findFolloweeCount(int userId, int entityType) {
            String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
            return redisTemplate.opsForZSet().zCard(followeeKey);
        }
    
        //  查询实体的粉丝数量
        public long findFollowerCount(int entityType, int entityId) {
            String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);
            return redisTemplate.opsForZSet().zCard(followerKey);
        }
    
    
        // 查询当前用户是否已关注实体  用户关注的实体
        public boolean hasFollowed(int userId, int entityType, int entityId) {
            String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
            return redisTemplate.opsForZSet().score(followeeKey, entityId) != null;
        }
    
        // 查询某用户关注的人
        public List<Map<String, Object>> findFollowees(int userId, int offset, int limit) {
            String followeeKey = RedisKeyUtil.getFolloweeKey(userId, ENTITY_TYPE_USER);
            Set<Integer> targetIds = redisTemplate.opsForZSet().reverseRange(followeeKey, offset, offset + limit - 1);
    
            if (targetIds == null) {
                return null;
            }
    
            List<Map<String, Object>> list = new ArrayList<>();
            for (Integer targetId : targetIds)  {
                Map<String, Object> map = new HashMap<>();
                User user = userService.findUserById(targetId);
                map.put("user", user);
                Double score = redisTemplate.opsForZSet().score(followeeKey, targetId);
                map.put("followTime", new Date(score.longValue()));
                list.add(map);
            }
            return list;
        }
    
        // 查询某用户的粉丝
        public List<Map<String, Object>> findFollowers(int userId, int offset, int limit) {
            String followerKey = RedisKeyUtil.getFollowerKey(ENTITY_TYPE_USER, userId);
            Set<Integer> targetIds = redisTemplate.opsForZSet().reverseRange(followerKey, offset, offset + limit - 1);
    
            if (targetIds == null) {
                return null;
            }
    
            List<Map<String, Object>> list = new ArrayList<>();
            for (Integer targetId : targetIds) {
                Map<String, Object> map = new HashMap<>();
                User user = userService.findUserById(targetId);
                map.put("user", user);
                Double score = redisTemplate.opsForZSet().score(followerKey, targetId);
                map.put("followTime", new Date(score.longValue()));
                list.add(map);
            }
    
            return list;
        }
        
    }

### 2. controller层 ###

在 `FolloweController` 类中添加 `getFollowees`、`getFollowers`、`hasFollowed` 方法，代码如下：

@Controller
    public class FollowController implements CommunityConstant {
    
        @Autowired
        private FollowService followService;
    
        @Autowired
        private HostHolder hostHolder;
    
        @Autowired
        private UserService userService;
    
        @RequestMapping(path = "/follow", method = RequestMethod.POST)
        @ResponseBody
        public String follow(int entityType, int entityId) {
            User user = hostHolder.getUser();
    
            followService.follow(user.getId(), entityType, entityId);
    
            return CommunityUtil.getJSONString(0, "已关注！");
        }
    
        @RequestMapping(path = "/unfollow", method = RequestMethod.POST)
        @ResponseBody
        public String unfollow(int entityType, int entityId) {
            User user = hostHolder.getUser();
    
            followService.unfollow(user.getId(), entityType, entityId);
    
            return CommunityUtil.getJSONString(0, "已取消关注!");
        }
    
    
        @RequestMapping(path = "/followees/{userId}", method = RequestMethod.GET)
        public String getFollowees(@PathVariable("userId") int userId, Page page, Model model) {
            User user = userService.findUserById(userId);
            if (user == null) {
                throw new RuntimeException("该用户不存在!");
            }
            model.addAttribute("user", user);
    
            page.setLimit(5);
            page.setPath("/followees/" + userId);
            page.setRows((int) followService.findFolloweeCount(userId, ENTITY_TYPE_USER));
    
            List<Map<String, Object>> userList = followService.findFollowees(userId, page.getOffset(), page.getLimit());
            if (userList != null) {
                for (Map<String, Object> map : userList) {
                    User u = (User) map.get("user");
                    map.put("hasFollowed", hasFollowed(u.getId()));
                }
            }
            model.addAttribute("users", userList);
    
            return "/site/followee";
        }
    
        @RequestMapping(path = "/followers/{userId}", method = RequestMethod.GET)
        public String getFollowers(@PathVariable("userId") int userId, Page page, Model model) {
            User user = userService.findUserById(userId);
            if (user == null) {
                throw new RuntimeException("该用户不存在!");
            }
            model.addAttribute("user", user);
    
            page.setLimit(5);
            page.setPath("/followers/" + userId);
            page.setRows((int) followService.findFollowerCount(ENTITY_TYPE_USER, userId));
    
            List<Map<String, Object>> userList = followService.findFollowers(userId, page.getOffset(), page.getLimit());
            if (userList != null) {
                for (Map<String, Object> map : userList) {
                    User u = (User) map.get("user");
                    map.put("hasFollowed", hasFollowed(u.getId()));
                }
            }
            model.addAttribute("users", userList);
    
            return "/site/follower";
        }
    
    
        private boolean hasFollowed(int userId) {
            if (hostHolder.getUser() == null) {
                return false;
            }
    
            return followService.hasFollowed(hostHolder.getUser().getId(), ENTITY_TYPE_USER, userId);
        }
    
    
    }

### 3. view层 ###

`profile.html`：

`followee.html`：

<ul class="nav nav-tabs mb-3">
               <li class="nav-item">
                     <a class="nav-link position-relative active" th:href="@{|/followees/${user.id}|}">
                          <i class="text-info" th:utext="${user.username}">Nowcoder</i> 关注的人
                      </a>
             </li>
                        <li class="nav-item">
                            <a class="nav-link position-relative" th:href="@{|/followers/${user.id}|}">
                                关注 <i class="text-info" th:utext="${user.username}">Nowcoder</i> 的人
                            </a>
                        </li>
                    </ul>
                    <a th:href="@{|/user/profile/${user.id}|}" class="text-muted position-absolute rt-0">返回个人主页></a>
     </div>

<ul class="list-unstyled">
                    <li class="media pb-3 pt-3 mb-3 border-bottom position-relative" th:each="map:${users}">
                        <a th:href="@{|/user/profile/${map.user.id}|}">
                            <img th:src="${map.user.headerUrl}" class="mr-4 rounded-circle user-header" alt="用户头像" >
                        </a>
                        <div class="media-body">
                            <h6 class="mt-0 mb-3">
                                <span class="text-success" th:utext="${map.user.username}">落基山脉下的闲人</span>
                                <span class="float-right text-muted font-size-12">
    									关注于 <i th:text="${#dates.format(map.followTime,'yyyy-MM-dd HH:mm:ss')}">2019-04-28 14:13:25</i>
    								</span>
                            </h6>
                            <div>
                                <input type="hidden" id="entityId" th:value="${map.user.id}">
                                <button type="button" th:class="|btn ${map.hasFollowed?'btn-secondary':'btn-info'} btn-sm float-right follow-btn|"
                                        th:if="${loginUser!=null && loginUser.id!=map.user.id}" th:text="${map.hasFollowed?'已关注':'关注TA'}">关注TA</button>
                            </div>
                        </div>
                    </li>
      </ul>

`follower.html`：

<div class="position-relative">
                    
                    <ul class="nav nav-tabs mb-3">
                        <li class="nav-item">
                            <a class="nav-link position-relative" th:href="@{|/followees/${user.id}|}">
                                <i class="text-info" th:utext="${user.username}">Nowcoder</i> 关注的人
                            </a>
                        </li>
                        <li class="nav-item">
                            <a class="nav-link position-relative active" th:href="@{|/followers/${user.id}|}">
                                关注 <i class="text-info" th:utext="${user.username}">Nowcoder</i> 的人
                            </a>
                        </li>
                    </ul>
                    <a th:href="@{|/user/profile/${user.id}|}" class="text-muted position-absolute rt-0">返回个人主页></a>
                </div>

<ul class="list-unstyled">
                    <li class="media pb-3 pt-3 mb-3 border-bottom position-relative" th:each="map:${users}">
                        <a th:href="@{|/user/profile/${map.user.id}|}">
                            <img th:src="${map.user.headerUrl}" class="mr-4 rounded-circle user-header" alt="用户头像" >
                        </a>
                        <div class="media-body">
                            <h6 class="mt-0 mb-3">
                                <span class="text-success" th:utext="${map.user.username}">落基山脉下的闲人</span>
                                <span class="float-right text-muted font-size-12">
    									关注于 <i th:text="${#dates.format(map.followTime,'yyyy-MM-dd HH:mm:ss')}">2019-04-28 14:13:25</i>
    								</span>
                            </h6>
                            <div>
                                <input type="hidden" id="entityId" th:value="${map.user.id}">
                                <button type="button" th:class="|btn ${map.hasFollowed?'btn-secondary':'btn-info'} btn-sm float-right follow-btn|"
                                        th:if="${loginUser!=null && loginUser.id!=map.user.id}" th:text="${map.hasFollowed?'已关注':'关注TA'}">关注TA</button>
                            </div>
                        </div>
                    </li>
                </ul>

### 4. 功能测试 ###

![在这里插入图片描述][f2eaa1a2100344be85612e88734af741.png]  
![在这里插入图片描述][d5258a7607ee45ab891e330f60d4bdf9.png]  
![在这里插入图片描述][4935c5c996ae49a49ba4a6f8b6741bae.png]  
![在这里插入图片描述][fbcb24b959284ab48283ac80ee46826f.png]

## 七、优化登录模块 ##

*  使用 `Redis` 存储验证码
    
     *  验证码需要频繁的访问与刷新，对性能要求较高。
     *  验证码不需永久保存，通常在很短的时间后就会失
     *  分布式部署时，存在`Session`共享的问题。
 *  使用`Redis`存储登录凭证
    
     *  处理每次请求时，都要查询用户的登录凭证，访问的频率非常高。
 *  使用`Redis`缓存用户信息
    
     *  处理每次请求时，都要根据凭证查询用户信息，访问的频率非常高。

### 1. util包 ###

在 `RedisKeyUtil` 中形成相关键的方法，代码如下：

public class RedisKeyUtil {
    
        public static final String SPLIT = ":";
    
        private static final String PREFIX_ENTITY_LIKE = "like:entity";
    
        private static final String PREFIX_USER_LIKE = "like:user";
    
        private static final String PREFIX_FOLLOWEE = "followee";
    
        private static final String PREFIX_FOLLOWER = "follower";
    
        private static final String PREFIX_KAPTCHA = "kaptcha";
    
        private static final String PREFIX_TICKET = "ticket";
    
        private static final String PREFIX_USER = "user";
    
    
    
        // 某个实体的赞
        // like:entity:entityType:entityId -> set(userId)
        public static String getEntityLikeKey(int entityType, int entityId) {
            return PREFIX_ENTITY_LIKE + SPLIT + entityType + SPLIT + entityId;
        }
    
        // 某个用户的赞
        //like:user: userId->int
        public static String getUserLikeKey(int userId) {
            return PREFIX_USER_LIKE + SPLIT + userId;
        }
    
        // 某个用户关注的实体（键：用户Id  值：实体Id）
        // followee:userId:entityType -> zset(entityId, now)
        public static String getFolloweeKey(int userId, int entityType) {
            return PREFIX_FOLLOWEE + SPLIT + userId + SPLIT + entityType;
        }
    
        // 某个实体拥有的粉丝 （键：实体Id  值：用户Id）
        // follower:entityType:entityId -> zset(userId, now)
        public static String getFollowerKey(int entityType, int entityId) {
            return PREFIX_FOLLOWER + SPLIT + entityType + SPLIT + entityId;
        }
    
        // 登录验证码
        public static String getKaptchaKey(String owner) {
            return PREFIX_KAPTCHA + SPLIT + owner;
        }
    
        // 登录的凭证
        public static String getTicketKey(String ticket) {
            return PREFIX_TICKET + SPLIT + ticket;
        }
    
        // 用户
        public static String getUserKey(int userId) {
            return PREFIX_USER + SPLIT + userId;
        }
    
    }

### 2. dao层 ###

在 `LoginTicketMapper` 类中添加 `Deprecated` 注解，代码如下：

@Deprecated
    public interface LoginTicketMapper {
    
        // 这里是用注解的方式进行编码
    
        @Insert({
                "insert into login_ticket(user_id,ticket,status,expired) ",
                "values(#{userId},#{ticket},#{status},#{expired})"
        })
        @Options(useGeneratedKeys = true, keyProperty = "id")
        int insertLoginTicket(LoginTicket loginTicket);
    
        @Select({
                "select id,user_id,ticket,status,expired ",
                "from login_ticket where ticket=#{ticket}"
        })
        LoginTicket selectByTicket(String ticket);
    
        @Update({
                "<script>",
                "update login_ticket set status=#{status} where ticket=#{ticket} ",
                "<if test=\"ticket!=null\"> ",
                "and 1=1 ",
                "</if>",
                "</script>"
        })
        int updateStatus(String ticket, int status);
    }

### 3. service层 ###

在 `UserSddervice` 中修改 `findUserId`、`login`、`findLoginTicket`、`updateheader`方法，并且添加 `getCache`、`initCache`、`clearCache` 方法，代码如下：

@Service
    public class UserService implements CommunityConstant {
    
        @Autowired
        private UserMapper userMapper;
    
        @Autowired
        private MailClient mailClient;
    
        @Autowired
        private TemplateEngine templateEngine;
    
    //    @Autowired
    //    private LoginTicketMapper loginTicketMapper;
    
        @Value("${community.path.domain}")
        private String domain;
    
        @Value("${server.servlet.context-path}")
        private String contextPath;
    
        @Autowired
        private RedisTemplate redisTemplate;
    
        public User findUserById(int id) {
    //        return userMapper.selectById(id);
            User user = getCache(id);
            if (user == null) {
                initCache(id);
            }
            return user;
        }
    
        public Map<String, Object> register(User user) {
            Map<String, Object> map = new HashMap<>();
    
            // 空值处理
            if (user == null) {
                throw new IllegalArgumentException("参数不能为空!");
            }
            if (StringUtils.isBlank(user.getUsername())) {
                map.put("usernameMsg", "账号不能为空!");
                return map;
            }
            if (StringUtils.isBlank(user.getPassword())) {
                map.put("passwordMsg", "密码不能为空!");
                return map;
            }
            if (StringUtils.isBlank(user.getEmail())) {
                map.put("emailMsg", "邮箱不能为空!");
                return map;
            }
    
            // 验证账号
            User u = userMapper.selectByName(user.getUsername());
            if (u != null) {
                map.put("usernameMsg", "该账号已存在!");
                return map;
            }
    
            // 验证邮箱
            u = userMapper.selectByEmail(user.getEmail());
            if (u != null) {
                map.put("emailMsg", "该邮箱已被注册!");
                return map;
            }
    
            // 注册用户
            user.setSalt(CommunityUtil.generateUUID().substring(0, 5));
            user.setPassword(CommunityUtil.md5(user.getPassword() + user.getSalt()));
            user.setType(0);
            user.setStatus(0);
            user.setActivationCode(CommunityUtil.generateUUID());
            user.setHeaderUrl(String.format("http://images.nowcoder.com/head/%dt.png", new Random().nextInt(1000)));
            user.setCreateTime(new Date());
            userMapper.insertUser(user);
    
            // 激活邮件
            Context context = new Context();
            context.setVariable("email", user.getEmail());
            // http://localhost:8080/community/activation/101/code
            String url = domain + contextPath + "/activation/" + user.getId() + "/" + user.getActivationCode();
            context.setVariable("url", url);
            String content = templateEngine.process("/mail/activation", context);
            mailClient.sendMail(user.getEmail(), "激活账号", content);
    
            return map;
        }
    
        public int activation(int userId, String code) {
            User user = userMapper.selectById(userId);
            if (user.getStatus() == 1) {
                return ACTIVATION_REPEAT;
            } else if (user.getActivationCode().equals(code)) {
                userMapper.updateStatus(userId, 1);
                clearCache(userId);
                return ACTIVATION_SUCCESS;
            } else {
                return ACTIVATION_FAILURE;
            }
        }
    
        // 登录
        public Map<String, Object> login(String username, String password, int expiredSeconds) {
            Map<String, Object> map = new HashMap<>();
    
            // 空值处理
            if (StringUtils.isBlank(username)) {
                map.put("usernameMsg", "账号不能为空！");
                return map;
            }
            if (StringUtils.isBlank(password)) {
                map.put("passwordMsg", "密码不能为空！");
                return map;
            }
    
            // 验证账号
            User user = userMapper.selectByName(username);
            if (user == null) {
                map.put("usernameMsg", "该账号不存在！");
                return map;
            }
    
            // 验证状态
            if (user.getStatus() == 0) {
                map.put("usernameMsg", "该账号未激活！");
                return map;
            }
    
            // 验证密码
            password = CommunityUtil.md5(password + user.getSalt());
            if (!user.getPassword().equals(password)) {
                map.put("passwordMsg", "密码不正确！");
                return map;
            }
    
            // 生成登录凭证
            LoginTicket loginTicket = new LoginTicket();
            loginTicket.setUserId(user.getId());
            loginTicket.setTicket(CommunityUtil.generateUUID());
            loginTicket.setStatus(0);
            loginTicket.setExpired(new Date(System.currentTimeMillis() + expiredSeconds * 1000));
    //        loginTicketMapper.insertLoginTicket(loginTicket);
    
            String redisKey = RedisKeyUtil.getTicketKey(loginTicket.getTicket());
            redisTemplate.opsForValue().set(redisKey, loginTicket);
    
            map.put("ticket", loginTicket.getTicket());
            return map;
    
        }
    
        // 退出登录
        public void logout(String ticket) {
    //        loginTicketMapper.updateStatus(ticket, 1);
            String redisKey = RedisKeyUtil.getTicketKey(ticket);
            LoginTicket loginTicket = (LoginTicket) redisTemplate.opsForValue().get(redisKey);
            loginTicket.setStatus(1);
            redisTemplate.opsForValue().set(redisKey, loginTicket);
        }
    
    
        public LoginTicket findLoginTicket(String ticket) {
    //        return loginTicketMapper.selectByTicket(ticket);
            String redisKey = RedisKeyUtil.getTicketKey(ticket);
            return (LoginTicket) redisTemplate.opsForValue().get(redisKey);
    
        }
    
    
        public int updateHeader(int userId, String headerUrl) {
    //        return userMapper.updateHeader(userId, headerUrl);
            int rows = userMapper.updateHeader(userId, headerUrl);
            clearCache(userId);
            return rows;
        }
    
        public User findUserByName(String username) {
            return userMapper.selectByName(username);
        }
    
        // 1. 优先从缓存中取值
        private User getCache(int userId) {
            String redisKey = RedisKeyUtil.getUserKey(userId);
            return (User) redisTemplate.opsForValue().get(redisKey);
        }
    
        // 2. 取不到时初始化缓存数据
        private User initCache(int userId) {
            User user = userMapper.selectById(userId);
            String redisKey = RedisKeyUtil.getUserKey(userId);
            redisTemplate.opsForValue().set(redisKey, user, 3600, TimeUnit.SECONDS);
            return user;
        }
    
    
        // 3. 数据变更时清除缓存数据
        private void clearCache(int userId) {
            String redisKey = RedisKeyUtil.getUserKey(userId);
            redisTemplate.delete(redisKey);
    
        }
    
    }

### 4. controller层 ###

在 `LoginController` 类中修改 `getKaptcha`、`login` 方法，代码如下：

@Controller
    public class LoginController implements CommunityConstant {
    
        private static final Logger logger = LoggerFactory.getLogger(LoginController.class);
    
        @Autowired
        private UserService userService;
    
        @Autowired
        private Producer kaptchaProducer;
    
        @Value("${server.servlet.context-path}")
        private String  contextPath;
    
        @Autowired
        private RedisTemplate redisTemplate;
    
        @RequestMapping(path = "register", method = RequestMethod.GET)
        public String getRegisterPage() {
            return "/site/register";
        }
    
        @RequestMapping(path = "/login", method = RequestMethod.GET)
        public String getLoginPage() {
            return "/site/login";
        }
    
    
        @RequestMapping(path = "/register", method = RequestMethod.POST)
        public String register(Model model, User user) throws IllegalAccessException {
            Map<String, Object> map = userService.register(user);
    
            if (map == null || map.isEmpty()) {
                model.addAttribute("msg", "注册成功，我们已经向您的邮箱发送了一份激活邮件，请尽快激活!");
                model.addAttribute("target", "/index");
                return "/site/operate-result";
            } else {
                model.addAttribute("usernameMsg", map.get("usernameMsg"));
                model.addAttribute("passwordMsg", map.get("passwordMsg"));
                model.addAttribute("emailMsg", map.get("emailMsg"));
                return "/site/register";
            }
    
        }
    
    
    
    
        // http://localhost:8080/community/activation/101/code
        @RequestMapping(path = "/activation/{userId}/{code}", method = RequestMethod.GET)
        public String activation(Model model, @PathVariable("userId") int userId, @PathVariable("code") String code) {
            int result = userService.activation(userId, code);
            if (result == ACTIVATION_SUCCESS) {
                model.addAttribute("msg", "激活成功，您的账号已经可以正常使用了！");
                model.addAttribute("target", "/login");
            } else if (result == ACTIVATION_REPEAT) {
                model.addAttribute("msg", "无效操作，该账号已经注册过了！");
                model.addAttribute("target", "/index");
            } else {
                model.addAttribute("msg", "激活失败，您提供的激活码不正确！");
                model.addAttribute("target", "/index");
            }
    
            return "/site/operate-result";
        }
    
    
    
    
        @RequestMapping(path = "/kaptcha", method = RequestMethod.GET)
        public void getKaptcha(HttpServletResponse response/*, HttpSession session*/) {
            // 生成验证码
            String text = kaptchaProducer.createText();
            BufferedImage image = kaptchaProducer.createImage(text);
    
            // 将验证码存入session
            //session.setAttribute("kaptcha", text);
    
            // 验证码的归属
            String kaptchaOwner = CommunityUtil.generateUUID();
            Cookie cookie = new Cookie("kaptchaOwner", kaptchaOwner);
            cookie.setMaxAge(60);
            cookie.setPath(contextPath);
            response.addCookie(cookie);
    
    
    
            // 将验证码存入Redis
            String redisKey = RedisKeyUtil.getKaptchaKey(kaptchaOwner);
            redisTemplate.opsForValue().set(redisKey, text, 60, TimeUnit.SECONDS);
    
    
            // 将图片输出给浏览器
            response.setContentType("image/png");
            try {
                OutputStream os = response.getOutputStream();
                ImageIO.write(image, "png", os);
            } catch (IOException e) {
                logger.error("响应验证码失败:" + e.getMessage());
            }
        }
    
    
        @RequestMapping(path = "/login", method = RequestMethod.POST)
        public String login(String username, String password, String code, boolean rememberme,
                            Model model, /*HttpSession session, */HttpServletResponse response, @CookieValue("kaptchaOwner") String kaptchaOwner) {
    
            // 检查验证码
            //String kaptcha = (String) session.getAttribute("kaptcha");
    
            String kaptcha = null;
            if (StringUtils.isNotBlank(kaptchaOwner)) {
                String redisKey = RedisKeyUtil.getKaptchaKey(kaptchaOwner);
                kaptcha = (String) redisTemplate.opsForValue().get(redisKey);
            }
    
            if (StringUtils.isBlank(kaptcha) || StringUtils.isBlank(code) || !kaptcha.equalsIgnoreCase(code)) {
                model.addAttribute("codeMsg", "验证码不正确!");
                return "/site/login";
            }
    
            // 检查账号、密码
            int expiredSeconds = rememberme ? REMEMBER_EXPIRED_SECONDS : DEFAULT_EXPIRED_SECONDS;
            Map<String, Object> map = userService.login(username, password, expiredSeconds);
    
            if (map.containsKey("ticket")) {
                Cookie cookie = new Cookie("ticket", map.get("ticket").toString());
                //在此路径上生效
                cookie.setPath(contextPath);
                //cookie生效时间
                cookie.setMaxAge(expiredSeconds);
                response.addCookie(cookie);
                return "redirect:/index";
            } else {
                model.addAttribute("usernameMsg", map.get("usernameMsg"));
                model.addAttribute("passwordMsg", map.get("passwordMsg"));
                return "/site/login";
            }
        }
    
        @RequestMapping(path = "/logout", method = RequestMethod.GET)
        public String logout(@CookieValue("ticket") String ticket) {
            userService.logout(ticket);
            return "redirect:/logout";
        }
    
    }

### 5. 功能测试 ###

**使用 `Redis` 存储验证码：**  
旧版：客户端不保存有验证信息，服务器保存一份验证码信息于 `session` 中。当多个用户从不同客户端发起访问时，则不能满足需求，因为服务器只会保存一条验证码信息，无法实现多用户登录。

改进：客户端只保存一份验证码信息（用`cookie`，多次刷新验证码则覆盖`cookie`，60s过后清除），服务端保存多份验证码信息（存储于`redis`中，60s过后清除），`cookie`中的`kaptchaOwner`值与`redis` 中的 `kaptcha:owner` 键一 一对应。

获取验证码时，客户端将随机字符串存储在`cookie`中，将随机字符串作为键，验证码的值作为值存储在`redis`中, 用户登录校验时，根据用户`cookie`传来的随机字符串查询`redis`数据库，获取验证码的值。

**测试：** 用户刷新后得到的验证码，生成的随机字符串是 “4dbbfb29857c4231a17032f68a791ea0”，验证码的值是“XLAG”,则：  
`cookie` 中存放的信息为：

kaptchaOwner: 4dbbfb29857c4231a17032f68a791ea0  // 60s过后删除

`redis` 中存放的信息为：

kaptcha:4dbbfb29857c4231a17032f68a791ea -> XLAG

**使用 `redis` 存储登录凭证：**  
旧版：客户端登录凭证存储在`cookie`中【`cookie`过期时间为`expiredSeconds`】，服务端登录凭证存储在`login_ticket MySQL`表中。

改进：客户端登录凭证存储在`cookie`中【cookie过期时间为`expiredSeconds`】，服务端登录凭证存储在`login_ticket Redis`数据库中。

**使用redis缓存用户信息:**  
旧版：用户信息仅存储在`user MySQL`表中。

改进：添加缓存，优先在缓存中取到用户实体。

public User findUserByName(String username) {
            return userMapper.selectByName(username);
        }
    
        // 1. 优先从缓存中取值
        private User getCache(int userId) {
            String redisKey = RedisKeyUtil.getUserKey(userId);
            return (User) redisTemplate.opsForValue().get(redisKey);
        }
    
        // 2. 取不到时初始化缓存数据
        private User initCache(int userId) {
            User user = userMapper.selectById(userId);
            String redisKey = RedisKeyUtil.getUserKey(userId);
            redisTemplate.opsForValue().set(redisKey, user, 3600, TimeUnit.SECONDS);
            return user;
        }
    
    
        // 3. 数据变更时清除缓存数据
        private void clearCache(int userId) {
            String redisKey = RedisKeyUtil.getUserKey(userId);
            redisTemplate.delete(redisKey);
    
        }

![在这里插入图片描述][b2468a88272c4d6aa48c0a61407d5030.png]  
![在这里插入图片描述][fdf44344c6dd452d919f5a57775ef660.png]

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