fix bugs

stmms-web/src/main/java/cn/com/qmth/stmms/api/controller/ExamStudentController.java

@@ -131,7 +131,7 @@ public class ExamStudentController extends BaseApiController {
                 obj.accumulate("subjectName", student.getSubjectName());
                 obj.accumulate("name", student.getName());
                 obj.accumulate("studentCode", student.getStudentCode());
-                obj.accumulate("packageCode", student.getPackageCode());
+                obj.accumulate("packageCode", StringUtils.trimToEmpty(student.getPackageCode()));
                 obj.accumulate("paperType", StringUtils.trimToEmpty(student.getPaperType()));
                 obj.accumulate("batchCode", StringUtils.trimToEmpty(student.getBatchCode()));
                 obj.accumulate("sheetCount", student.getSheetCount() != null ? student.getSheetCount() : 0);