用户访问统计使用缓存+定时任务

+ 重要：注释的地方如果没用到@nagisa77可以删除

backend/src/main/java/com/openisle/service/UserVisitService.java

@@ -1,15 +1,22 @@
 package com.openisle.service;
 
+import com.openisle.config.CachingConfig;
 import com.openisle.model.User;
 import com.openisle.model.UserVisit;
 import com.openisle.repository.UserRepository;
 import com.openisle.repository.UserVisitRepository;
 import lombok.RequiredArgsConstructor;
+import org.springframework.cache.annotation.CacheConfig;
+import org.springframework.data.redis.core.RedisTemplate;
 import org.springframework.stereotype.Service;
+import org.springframework.util.CollectionUtils;
 
+import java.time.Duration;
 import java.time.LocalDate;
+import java.time.LocalDateTime;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.Set;
 
 @Service
 @RequiredArgsConstructor
@@ -17,6 +24,8 @@ public class UserVisitService {
     private final UserVisitRepository userVisitRepository;
     private final UserRepository userRepository;
 
+    private final RedisTemplate redisTemplate;
+
     public boolean recordVisit(String username) {
         User user = userRepository.findByUsername(username)
                 .orElseThrow(() -> new com.openisle.exception.NotFoundException("User not found"));
@@ -30,10 +39,36 @@ public class UserVisitService {
         });
     }
 
+    /**
+     * 统计访问次数，改为从缓存获取/数据库获取
+     * @param username
+     * @return
+     */
     public long countVisits(String username) {
         User user = userRepository.findByUsername(username)
                 .orElseThrow(() -> new com.openisle.exception.NotFoundException("User not found"));
-        return userVisitRepository.countByUser(user);
+
+        // 如果缓存存在就返回
+        String key1 = CachingConfig.VISIT_CACHE_NAME + ":"+LocalDate.now()+":count:"+username;
+        Integer cached = (Integer) redisTemplate.opsForValue().get(key1);
+        if(cached != null){
+            return cached.longValue();
+        }
+
+        // Redis Set 检查今天是否访问
+        String todayKey = CachingConfig.VISIT_CACHE_NAME + ":" + LocalDate.now();
+        boolean todayVisited = redisTemplate.opsForSet().isMember(todayKey, username);
+
+        Long visitCount = userVisitRepository.countByUser(user);
+        if (todayVisited) visitCount += 1;
+
+        LocalDateTime now = LocalDateTime.now();
+        LocalDateTime endOfDay = now.toLocalDate().atTime(23, 59, 59);
+        long secondsUntilEndOfDay = Duration.between(now, endOfDay).getSeconds();
+
+        // 写入缓存，设置 TTL，当天剩余时间
+        redisTemplate.opsForValue().set(key1, visitCount, Duration.ofSeconds(secondsUntilEndOfDay));
+        return visitCount;
     }
 
     public long countDau(LocalDate date) {