From 58cb64814f71c327dfc8194f76a22c8f5962574b Mon Sep 17 00:00:00 2001
From: wanghu <wanghu@yunhai.com>
Date: Mon, 17 Aug 2026 09:21:56 +0800
Subject: [PATCH] =?UTF-8?q?=E7=BC=93=E5=AD=98=E5=91=BD=E4=B8=AD=E6=B1=A1?=
 =?UTF-8?q?=E6=9F=93?=
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---
 .../impl/BaseSchsystemGradeService.java       | 19 ++++++++++--
 .../service/impl/BaseSchsystemService.java    | 31 ++++++++++++++-----
 2 files changed, 39 insertions(+), 11 deletions(-)

diff --git a/src/main/java/com/yunhai/bschclassmanage/service/impl/BaseSchsystemGradeService.java b/src/main/java/com/yunhai/bschclassmanage/service/impl/BaseSchsystemGradeService.java
index cd6e7cc..35be569 100644
--- a/src/main/java/com/yunhai/bschclassmanage/service/impl/BaseSchsystemGradeService.java
+++ b/src/main/java/com/yunhai/bschclassmanage/service/impl/BaseSchsystemGradeService.java
@@ -41,17 +41,30 @@ public class BaseSchsystemGradeService implements IBaseSchsystemGradeService {
 
         String cacheKey = RedisConstants.SCHOOL_GRAGE+"_"+schId;
 
-        if (redisUtil.hasKey(cacheKey))
-            return redisUtil.getList(cacheKey,BaseSchsystemGrade.class);
+        // 空结果（null 或 空列表）视为未命中，回源 DB，避免空缓存长期毒化
+        List<BaseSchsystemGrade> cached = redisUtil.getList(cacheKey, BaseSchsystemGrade.class);
+        if (cached != null && !cached.isEmpty()) {
+            return cached;
+        }
 
         List<Integer> schsystemIds= schBinSchsystemService.getSchBinSchsystemIds(schId);
 
         List<BaseSchsystemGrade> list=baseSchsystemGradeRepository.findBySchSystemIdIn(schsystemIds);
 
-        redisUtil.set(cacheKey, list , RedisConstants.CACHE_EXPIRE_30D);
+        // 仅缓存非空结果
+        if (!list.isEmpty()) {
+            redisUtil.set(cacheKey, list , RedisConstants.CACHE_EXPIRE_30D);
+        }
         return list;
     }
 
+    /**
+     * 学校学制年级数据变更后调用：清除指定学校的学制年级缓存
+     */
+    public void clearSchGradeCache(Integer schId) {
+        redisUtil.del(RedisConstants.SCHOOL_GRAGE + "_" + schId);
+    }
+
 
     public  List<BaseSchsystemGrade> getSchGradeCacheList(Integer schId,Integer schsystemId,Integer gradeId) {
         List<BaseSchsystemGrade> list = getSchGradeCacheList(schId);
diff --git a/src/main/java/com/yunhai/bschclassmanage/service/impl/BaseSchsystemService.java b/src/main/java/com/yunhai/bschclassmanage/service/impl/BaseSchsystemService.java
index fbcd9df..bb54ea3 100644
--- a/src/main/java/com/yunhai/bschclassmanage/service/impl/BaseSchsystemService.java
+++ b/src/main/java/com/yunhai/bschclassmanage/service/impl/BaseSchsystemService.java
@@ -27,21 +27,36 @@ public class BaseSchsystemService implements IBaseSchsystemService {
     public List<BaseSchsystem> getSchsystemList() {
         String cacheKey = RedisConstants.SYSTEM_SCHSYSTEM;
 
-        if (redisUtil.hasKey(cacheKey))
-            return redisUtil.getList(cacheKey,BaseSchsystem.class);
+        // 1. 先读缓存；空结果（null 或 空列表）视为未命中，强制回源 DB，
+        //    避免“冷启动时把 [] 写进缓存后长期毒化”的问题
+        List<BaseSchsystem> cached = redisUtil.getList(cacheKey, BaseSchsystem.class);
+        if (cached != null && !cached.isEmpty()) {
+            return cached;
+        }
 
-        //加锁防止缓存击穿
+        // 2. 加锁防止缓存击穿 + 双重检查
         synchronized (this) {
-            // 双重检查
-            if (redisUtil.hasKey(cacheKey))
-                return redisUtil.getList(cacheKey,BaseSchsystem.class);
+            cached = redisUtil.getList(cacheKey, BaseSchsystem.class);
+            if (cached != null && !cached.isEmpty()) {
+                return cached;
+            }
 
             // 3. 从数据库查询
             List<BaseSchsystem> list = baseSchSystemRepository.findAll();
-            // 4. 存入缓存（即使是空列表也缓存，避免穿透）
-            redisUtil.set(cacheKey, list, RedisConstants.CACHE_EXPIRE_30D);
+
+            // 4. 仅缓存非空结果；空结果不缓存，防止空缓存污染（穿透风险可忽略）
+            if (!list.isEmpty()) {
+                redisUtil.set(cacheKey, list, RedisConstants.CACHE_EXPIRE_30D);
+            }
             return list;
         }
     }
 
+    /**
+     * 学制数据变更后调用：清除学制列表缓存（base_sch_system 写入/更新/删除时触发）
+     */
+    public void clearSchsystemCache() {
+        redisUtil.del(RedisConstants.SYSTEM_SCHSYSTEM);
+    }
+
 }