功能追加：显示在线人数

backend/src/main/java/com/openisle/config/CachingConfig.java

@@ -36,6 +36,8 @@ public class CachingConfig {
     public static final String TAG_CACHE_NAME="openisle_tags";
     // 分类缓存名
     public static final String CATEGORY_CACHE_NAME="openisle_categories";
+    // 在线人数缓存名
+    public static final String ONLINE_CACHE_NAME="openisle_online";
 
     /**
      * 自定义Redis的序列化器

backend/src/main/java/com/openisle/config/SecurityConfig.java

@@ -129,6 +129,8 @@ public class SecurityConfig {
                     .requestMatchers(HttpMethod.GET, "/api/sitemap.xml").permitAll()
                     .requestMatchers(HttpMethod.GET, "/api/channels").permitAll()
                     .requestMatchers(HttpMethod.GET, "/api/rss").permitAll()
+                    .requestMatchers(HttpMethod.GET, "/api/online/**").permitAll()
+                    .requestMatchers(HttpMethod.POST, "/api/online/**").permitAll()
                     .requestMatchers(HttpMethod.GET, "/api/point-goods").permitAll()
                     .requestMatchers(HttpMethod.POST, "/api/point-goods").permitAll()
                     .requestMatchers(HttpMethod.POST, "/api/categories/**").hasAuthority("ADMIN")
@@ -183,7 +185,8 @@ public class SecurityConfig {
                     }
                 } else if (!uri.startsWith("/api/auth") && !publicGet
                         && !uri.startsWith("/api/ws") && !uri.startsWith("/api/sockjs")
-                        && !uri.startsWith("/api/v3/api-docs")) {
+                        && !uri.startsWith("/api/v3/api-docs")
+                        && !uri.startsWith("/api/online")) {
                     response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
                     response.setContentType("application/json");
                     response.getWriter().write("{\"error\": \"Missing token\"}");

backend/src/main/java/com/openisle/controller/OnlineController.java

@@ -0,0 +1,33 @@
+package com.openisle.controller;
+
+import com.openisle.config.CachingConfig;
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.data.redis.core.StringRedisTemplate;
+import org.springframework.web.bind.annotation.*;
+
+import java.time.Duration;
+
+/**
+ * @author smallclover
+ * @since 2025-09-05
+ * 统计在线人数
+ */
+@RestController
+@RequestMapping("/api/online")
+@RequiredArgsConstructor
+public class OnlineController {
+
+    private final RedisTemplate redisTemplate;
+    private static final String ONLINE_KEY = CachingConfig.ONLINE_CACHE_NAME +":";
+
+    @PostMapping("/heartbeat")
+    public void ping(@RequestParam String userId){
+        redisTemplate.opsForValue().set(ONLINE_KEY+userId,"1", Duration.ofSeconds(150));
+    }
+
+    @GetMapping("/count")
+    public long count(){
+        return redisTemplate.keys(ONLINE_KEY+"*").size();
+    }
+}

frontend_nuxt/components/HeaderComponent.vue

@@ -37,7 +37,12 @@
             邀请
             <i v-if="isCopying" class="fas fa-spinner fa-spin"></i>
           </div>
-
+          <ToolTip v-if="!isMobile" content="当前在线人数" placement="bottom">
+            <div class="online-count">
+              <i class="fas fa-people-group"></i>
+              <span>{{ onlineCount }}</span>
+            </div>
+          </ToolTip>
           <ToolTip content="复制RSS链接" placement="bottom">
             <div class="rss-icon" @click="copyRssLink">
               <i class="fas fa-rss"></i>
@@ -115,6 +120,46 @@ const userMenu = ref(null)
 const menuBtn = ref(null)
 const isCopying = ref(false)
 
+const onlineCount = ref(0)
+
+// 心跳检测
+async function sendPing() {
+  try {
+    // 已登录就用 userId，否则随机生成游客ID
+    let userId = authState.userId
+    if (userId) {
+      // 用户已登录，清理游客 ID
+      localStorage.removeItem('guestId')
+    } else {
+      // 游客模式
+      let savedId = localStorage.getItem('guestId')
+      if (!savedId) {
+        savedId = `guest-${crypto.randomUUID()}`
+        localStorage.setItem('guestId', savedId)
+      }
+      userId = savedId
+    }
+    const res = await fetch(`${API_BASE_URL}/api/online/heartbeat?userId=${userId}`, {
+      method: 'POST',
+    })
+  } catch (e) {
+    console.error("心跳失败", e)
+  }
+}
+
+// 获取在线人数
+async function fetchCount() {
+  try {
+    const res = await fetch(`${API_BASE_URL}/api/online/count`, {
+      method: 'GET',
+    })
+    onlineCount.value = await res.json()
+  } catch (e) {
+    console.error("获取在线人数失败", e)
+  }
+}
+
+
 const search = () => {
   showSearch.value = true
   nextTick(() => {
@@ -262,6 +307,12 @@ onMounted(async () => {
       await updateUnread()
     },
   )
+
+  // 新增的在线人数逻辑
+  sendPing()
+  fetchCount()
+  setInterval(sendPing, 120000)   // 每 2 分钟发一次心跳
+  setInterval(fetchCount, 60000)  // 每 1 分更新 UI
 })
 </script>
 
@@ -452,6 +503,15 @@ onMounted(async () => {
   animation: rss-glow 2s 3;
 }
 
+.online-count {
+  font-size: 14px;
+  display: flex;
+  align-items: center;
+  gap: 5px;
+  color: var(--primary-color);
+  cursor: default;
+}
+
 @keyframes rss-glow {
   0% {
     text-shadow: 0 0 0px var(--primary-color);