bug fix

examcloud-core-oe-admin-service/src/main/java/cn/com/qmth/examcloud/core/oe/admin/service/impl/ExamStudentServiceImpl.java

@@ -273,7 +273,7 @@ public class ExamStudentServiceImpl implements ExamStudentService {
                 sql.append(" and finished = " + query.getFinished());
             } else if (ExamType.OFFLINE.name().equals(examType)) {
                 //如果忽略是否上传答案时，只要是已抽题则认为已参加考试
-                if (true==query.getIgnoreUploadOfflineAnswer()){
+                if (query.getIgnoreUploadOfflineAnswer()!=null && true==query.getIgnoreUploadOfflineAnswer()){
                     sql.append(" and finished = " + query.getFinished());
                 }else {
                     if (query.getFinished() == 0) {                    //未抽题