优化用户会话sessionId

api/ai-agent/src/main/java/cn/qihangerp/erp/serviceImpl/SessionManager.java

@@ -1,10 +1,14 @@
 package cn.qihangerp.erp.serviceImpl;
 
+import java.util.List;
 import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
+import cn.qihangerp.service.IAiConversationHistoryService;
+
 /**
  * 会话管理服务，用于管理用户的会话ID
  */
@@ -13,6 +17,9 @@ public class SessionManager {
     private static final Map<Long, String> userIdSessionMap = new ConcurrentHashMap<>();
     private static final Map<String, Long> sessionUserIdMap = new ConcurrentHashMap<>();
     
+    @Autowired
+    private IAiConversationHistoryService aiConversationHistoryService;
+
     /**
      * 获取或创建用户的会话ID
      * @param userId 用户ID
@@ -22,11 +29,28 @@ public class SessionManager {
         if (userId == null) {
             return null;
         }
-        return userIdSessionMap.computeIfAbsent(userId, k -> {
-            String sessionId = UUID.randomUUID().toString();
+        
+        // 先从内存缓存中获取
+        String sessionId = userIdSessionMap.get(userId);
+        if (sessionId != null) {
+            return sessionId;
+        }
+        
+        // 内存缓存中没有，从数据库中查找
+        List<String> sessionIds = aiConversationHistoryService.getSessionIdsByUserId(userId);
+        if (sessionIds != null && !sessionIds.isEmpty()) {
+            // 使用第一个会话ID
+            sessionId = sessionIds.get(0);
+            userIdSessionMap.put(userId, sessionId);
+            sessionUserIdMap.put(sessionId, userId);
+            return sessionId;
+        }
+        
+        // 数据库中也没有，创建新的会话ID
+        sessionId = UUID.randomUUID().toString();
+        userIdSessionMap.put(userId, sessionId);
         sessionUserIdMap.put(sessionId, userId);
         return sessionId;
-        });
     }
 
     /**

mapper/src/main/resources/mapper/AiConversationHistoryMapper.xml

@@ -37,10 +37,14 @@
     </select>
 
     <select id="selectSessionIdsByUserId" parameterType="Long" resultType="String">
-        select distinct session_id
+        select session_id
+        from (
+            select session_id, max(create_time) as max_create_time
             from ai_conversation_history
             where user_id = #{userId}
-        order by create_time desc
+            group by session_id
+        ) as temp
+        order by max_create_time desc
     </select>
 
     <delete id="deleteBySessionId" parameterType="String">