fix bugs

stmms-biz/src/main/java/cn/com/qmth/stmms/biz/exam/dao/ExamStudentDao.java

@@ -201,10 +201,10 @@ public interface ExamStudentDao extends PagingAndSortingRepository<ExamStudent,
     public List<ExamStudent> findByExamIdAndStudentCodeAndSubjectCode(int examId, String studentCode, String subjectCode);
 
     @Query("select sum(s.sheetCount) from ExamStudent s where s.examId=?1 ")
-    public long sumSheetCountByExamId(Integer examId);
+    public Long sumSheetCountByExamId(Integer examId);
 
     @Query("select sum(s.sheetCount) from ExamStudent s where s.examId=?1 and s.subjectCode=?2 ")
-    public long sumSheetCountByExamIdAndSubjectCode(int examId, String subjectCode);
+    public Long sumSheetCountByExamIdAndSubjectCode(int examId, String subjectCode);
 
     @Query("select distinct m.subjectCode from ExamStudent m where m.examId=?1 and m.subjectiveStatus in (?2)  and m.upload=true and m.absent=false and m.breach=false ")
     Set<String> findSubjectUnInspectedByExamId(int examId, SubjectiveStatus... status);

stmms-biz/src/main/java/cn/com/qmth/stmms/biz/exam/service/impl/ExamStudentServiceImpl.java

@@ -1123,12 +1123,14 @@ public class ExamStudentServiceImpl extends BaseQueryService<ExamStudent> implem
 
     @Override
     public long countSheetCountByExamId(Integer examId) {
-        return studentDao.sumSheetCountByExamId(examId);
+        Long count = studentDao.sumSheetCountByExamId(examId);
+        return count == null ? 0 : count;
     }
 
     @Override
     public long countSheetCountByExamIdAndSubjectCode(int examId, String code) {
-        return studentDao.sumSheetCountByExamIdAndSubjectCode(examId, code);
+        Long count = studentDao.sumSheetCountByExamIdAndSubjectCode(examId, code);
+        return count == null ? 0 : count;
     }
 
     @Override