bug fix

examcloud-core-oe-admin-service/src/main/java/cn/com/qmth/examcloud/core/oe/admin/service/cache/ExamStudentCache.java

@@ -20,8 +20,7 @@ public class ExamStudentCache extends RandomObjectRedisCache<ExamStudentCacheBea
 
 		Long examStudentId = (Long) keys[0];
 
-		ExamStudentEntity e = GlobalHelper.getPresentEntity(examStudentRepo, examStudentId,
-				ExamStudentEntity.class);
+		ExamStudentEntity e = examStudentRepo.findByExamStudentId(examStudentId);
 
 		ExamStudentCacheBean b = new ExamStudentCacheBean();
 		b.setCourseId(e.getCourseId());