修复通知公告longblob类型乱码问题

ruoyi-system/src/main/resources/mapper/system/SysNoticeMapper.xml

@@ -18,7 +18,7 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
     </resultMap>
     
     <sql id="selectNoticeVo">
-        select notice_id, notice_title, notice_type, notice_content, status, create_by, create_time, update_by, update_time, remark 
+        select notice_id, notice_title, notice_type, cast(notice_content as char) as notice_content, status, create_by, create_time, update_by, update_time, remark 
 		from sys_notice
     </sql>