fix

mec-biz/src/main/java/com/ym/mec/biz/service/impl/StudentCourseHomeworkServiceImpl.java

@@ -863,12 +863,15 @@ public class StudentCourseHomeworkServiceImpl extends BaseServiceImpl<Long, Stud
     public List<StudentCourseHomework> findExtraExerciseStudentsV2(StudentLessonTrainingDetailWrapper.StudentLessonTrainingQuery query) {
         List<StudentCourseHomework> extraExerciseStudents = extracurricularExercisesReplyService.findExtraExerciseStudents(
             query.getCourseScheduleId().longValue(), null);
+
+        List<StudentCourseHomework> studentCourseHomeworks = getStudentCourseHomeworks(extraExerciseStudents);
         if (query.getSubjectId() != null) {
-            extraExerciseStudents = extraExerciseStudents.stream()
+            studentCourseHomeworks = studentCourseHomeworks.stream()
+                                                         .filter(o ->o.getSubjectId() != null)
                                                          .filter(o -> o.getSubjectId().equals(query.getSubjectId()))
                                                          .collect(Collectors.toList());
         }
-        return getStudentCourseHomeworks(extraExerciseStudents);
+        return studentCourseHomeworks;
     }
 
     /**