Development: Fix a NullPointerException in RepositoryAccessService

src/main/java/de/tum/in/www1/artemis/domain/BaseExercise.java

@@ -29,7 +29,7 @@ public abstract class BaseExercise extends DomainObject {
     @JsonView(QuizView.Before.class)
     private String shortName;
 
-    @Column(name = "max_points")
+    @Column(name = "max_points", nullable = false)
     private Double maxPoints;
 
     @Column(name = "bonus_points")
@@ -41,23 +41,27 @@ public abstract class BaseExercise extends DomainObject {
 
     @Column(name = "release_date")
     @JsonView(QuizView.Before.class)
+    @Nullable
     private ZonedDateTime releaseDate;
 
     // TODO: Also use for quiz exercises
     @Column(name = "start_date")
     @JsonView(QuizView.Before.class)
+    @Nullable
     private ZonedDateTime startDate;
 
     @Column(name = "due_date")
     @JsonView(QuizView.Before.class)
+    @Nullable
     private ZonedDateTime dueDate;
 
     @Column(name = "assessment_due_date")
     @JsonView(QuizView.Before.class)
+    @Nullable
     private ZonedDateTime assessmentDueDate;
 
-    @Nullable
     @Column(name = "example_solution_publication_date")
+    @Nullable
     private ZonedDateTime exampleSolutionPublicationDate;
 
     @Enumerated(EnumType.STRING)
@@ -115,35 +119,39 @@ public void setAssessmentType(AssessmentType assessmentType) {
         this.assessmentType = assessmentType;
     }
 
+    @Nullable
     public ZonedDateTime getReleaseDate() {
         return releaseDate;
     }
 
-    public void setReleaseDate(ZonedDateTime releaseDate) {
+    public void setReleaseDate(@Nullable ZonedDateTime releaseDate) {
         this.releaseDate = releaseDate;
     }
 
+    @Nullable
     public ZonedDateTime getStartDate() {
         return startDate;
     }
 
-    public void setStartDate(ZonedDateTime startDate) {
+    public void setStartDate(@Nullable ZonedDateTime startDate) {
         this.startDate = startDate;
     }
 
+    @Nullable
     public ZonedDateTime getDueDate() {
         return dueDate;
     }
 
-    public void setDueDate(ZonedDateTime dueDate) {
+    public void setDueDate(@Nullable ZonedDateTime dueDate) {
         this.dueDate = dueDate;
     }
 
+    @Nullable
     public ZonedDateTime getAssessmentDueDate() {
         return assessmentDueDate;
     }
 
-    public void setAssessmentDueDate(ZonedDateTime assessmentDueDate) {
+    public void setAssessmentDueDate(@Nullable ZonedDateTime assessmentDueDate) {
         this.assessmentDueDate = assessmentDueDate;
     }
 

src/main/java/de/tum/in/www1/artemis/domain/Exercise.java

@@ -842,6 +842,7 @@ public void checkCourseAndExerciseGroupExclusivity(String entityName) throws Bad
      * @return the time from which on access to the participation is allowed, for exercises that are not part of an exam, this is just the release date or start date.
      */
     @JsonIgnore
+    @Nullable
     public ZonedDateTime getParticipationStartDate() {
         if (isExamExercise()) {
             return getExerciseGroup().getExam().getStartDate();

src/main/java/de/tum/in/www1/artemis/repository/CompetencyRelationRepository.java

@@ -22,7 +22,7 @@
 @Repository
 public interface CompetencyRelationRepository extends JpaRepository<CompetencyRelation, Long> {
 
-    @Transactional
+    @Transactional // ok because of delete
     @Modifying
     @Query("""
             DELETE FROM CompetencyRelation relation

src/main/java/de/tum/in/www1/artemis/repository/ExamLiveEventRepository.java

@@ -56,6 +56,6 @@ public interface ExamLiveEventRepository extends JpaRepository<ExamLiveEvent, Lo
      *
      * @param examId the id of the exam
      */
-    @Transactional // delete
+    @Transactional // ok because of delete
     void deleteAllByExamId(Long examId);
 }

src/main/java/de/tum/in/www1/artemis/repository/PushNotificationDeviceConfigurationRepository.java

@@ -41,7 +41,7 @@ WHERE p.expirationDate > NOW()
     /**
      * Cleans up the old/expired push notifications device configurations
      */
-    @Transactional
+    @Transactional // ok because of delete
     @Modifying
     @Query("""
             DELETE FROM PushNotificationDeviceConfiguration p

src/main/java/de/tum/in/www1/artemis/repository/UserRepository.java

@@ -495,7 +495,7 @@ OR CONCAT_WS(' ', user.firstName, user.lastName) LIKE %:#{#loginOrName}%
     void updateUserLanguageKey(@Param("userId") long userId, @Param("languageKey") String languageKey);
 
     @Modifying
-    @Transactional
+    @Transactional // ok because of modifying query
     @Query("""
             UPDATE User user
             SET user.irisAccepted = :acceptDatetime

src/main/java/de/tum/in/www1/artemis/repository/metis/ConversationParticipantRepository.java

@@ -107,7 +107,7 @@ default ConversationParticipant findConversationParticipantByConversationIdAndUs
      * @param senderId       userId of the sender of the message(Post)
      * @param conversationId conversationId id of the conversation with participants
      */
-    @Transactional
+    @Transactional // ok because of modifying query
     @Modifying
     @Query("""
             UPDATE ConversationParticipant conversationParticipant

src/main/java/de/tum/in/www1/artemis/repository/tutorialgroups/TutorialGroupNotificationRepository.java

@@ -15,7 +15,7 @@
 @Repository
 public interface TutorialGroupNotificationRepository extends JpaRepository<TutorialGroupNotification, Long> {
 
-    @Transactional
+    @Transactional // ok because of delete
     @Modifying
     void deleteAllByTutorialGroupId(Long tutorialGroupId);
 }

src/main/java/de/tum/in/www1/artemis/repository/tutorialgroups/TutorialGroupRegistrationRepository.java

@@ -30,17 +30,16 @@ Optional<TutorialGroupRegistration> findTutorialGroupRegistrationByTutorialGroup
 
     Set<TutorialGroupRegistration> findAllByTutorialGroup(TutorialGroup tutorialGroup);
 
+    @Transactional // ok because of delete
     @Modifying
-    @Transactional
-    // ok because of delete
     void deleteAllByStudent(User student);
 
-    @Transactional
+    @Transactional  // ok because of delete
     @Modifying
     void deleteById(@NotNull Long tutorialGroupRegistrationId);
 
+    @Transactional  // ok because of delete
     @Modifying
-    @Transactional
     void deleteAllByStudentIsInAndTypeAndTutorialGroupCourse(Set<User> students, TutorialGroupRegistrationType type, Course course);
 
     boolean existsByTutorialGroupTitleAndStudentAndType(String title, User student, TutorialGroupRegistrationType type);

src/main/java/de/tum/in/www1/artemis/repository/tutorialgroups/TutorialGroupRepository.java

@@ -6,18 +6,14 @@
 import java.util.Optional;
 import java.util.Set;
 
-import javax.transaction.Transactional;
-
 import org.springframework.cache.annotation.Cacheable;
 import org.springframework.context.annotation.Profile;
 import org.springframework.data.jpa.repository.JpaRepository;
-import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
 import de.tum.in.www1.artemis.domain.Course;
-import de.tum.in.www1.artemis.domain.User;
 import de.tum.in.www1.artemis.domain.metis.conversation.Channel;
 import de.tum.in.www1.artemis.domain.tutorialgroups.TutorialGroup;
 import de.tum.in.www1.artemis.web.rest.errors.EntityNotFoundException;
@@ -138,13 +134,6 @@ public interface TutorialGroupRepository extends JpaRepository<TutorialGroup, Lo
 
     boolean existsByTitleAndCourseId(String title, Long courseId);
 
-    Set<TutorialGroup> findAllByTeachingAssistant(User teachingAssistant);
-
-    @Transactional
-    @Modifying
-    // ok because of delete
-    void deleteAllByCourse(Course course);
-
     @Query("""
             SELECT tutorialGroup
             FROM TutorialGroup tutorialGroup

src/main/java/de/tum/in/www1/artemis/repository/tutorialgroups/TutorialGroupSessionRepository.java

@@ -86,12 +86,12 @@ default TutorialGroupSession findByIdElseThrow(long tutorialGroupSessionId) {
         return findById(tutorialGroupSessionId).orElseThrow(() -> new EntityNotFoundException("TutorialGroupSession", tutorialGroupSessionId));
     }
 
+    @Transactional // ok because of delete
     @Modifying
-    @Transactional
     void deleteByTutorialGroupCourse(Course course);
 
+    @Transactional // ok because of delete
     @Modifying
-    @Transactional
     void deleteByTutorialGroupSchedule(TutorialGroupSchedule tutorialGroupSchedule);
 
 }

src/main/java/de/tum/in/www1/artemis/service/RepositoryAccessService.java

@@ -4,6 +4,8 @@
 
 import java.time.ZonedDateTime;
 
+import javax.annotation.Nullable;
+
 import org.springframework.context.annotation.Profile;
 import org.springframework.stereotype.Service;
 
@@ -64,7 +66,10 @@ public void checkAccessRepositoryElseThrow(ProgrammingExerciseParticipation prog
         boolean isStudent = authorizationCheckService.isOnlyStudentInCourse(programmingExercise.getCourseViaExerciseGroupOrCourseMember(), user);
         boolean isTeachingAssistant = !isStudent && !isAtLeastEditor;
         boolean isStudentParticipation = programmingParticipation instanceof StudentParticipation;
-        var exerciseStartDate = programmingExercise.getParticipationStartDate();
+
+        // NOTE: the exerciseStartDate can be null, e.g. if no release and no start is defined for a course exercise
+        @Nullable
+        ZonedDateTime exerciseStartDate = programmingExercise.getParticipationStartDate();
 
         // Error case 1: The user does not have permissions to access the participation or the submission for plagiarism comparison.
         checkHasParticipationPermissionsOrCanAccessSubmissionForPlagiarismComparisonElseThrow(programmingParticipation, user, programmingExercise);
@@ -111,9 +116,9 @@ public void checkAccessRepositoryElseThrow(ProgrammingExerciseParticipation prog
      * @param exerciseStartDate        The start date of the exercise.
      */
     private void checkIsStudentAllowedToAccessRepositoryConcerningDates(ProgrammingExerciseParticipation programmingParticipation, RepositoryActionType repositoryActionType,
-            ZonedDateTime exerciseStartDate) {
+            @Nullable ZonedDateTime exerciseStartDate) {
         // if the exercise has not started yet, the student is not allowed to access the repository
-        if (exerciseStartDate.isAfter(ZonedDateTime.now())) {
+        if (exerciseStartDate != null && exerciseStartDate.isAfter(ZonedDateTime.now())) {
             throw new AccessForbiddenException();
         }
         else {

src/main/java/de/tum/in/www1/artemis/service/exam/StudentExamService.java

@@ -806,7 +806,7 @@ private StudentExam generateIndividualStudentExam(Exam exam, User student) {
      * @param exam with eagerly loaded registered users, exerciseGroups and exercises loaded
      * @return the list of student exams with their corresponding users
      */
-    @Transactional
+    @Transactional // TODO: NOT OK --> remove @Transactional
     public List<StudentExam> generateStudentExams(final Exam exam) {
         final var existingStudentExams = studentExamRepository.findByExamId(exam.getId());
         // https://jira.spring.io/browse/DATAJPA-1367 deleteInBatch does not work, because it does not cascade the deletion of existing exam sessions, therefore use deleteAll
@@ -827,7 +827,7 @@ public List<StudentExam> generateStudentExams(final Exam exam) {
      * @param exam with eagerly loaded registered users, exerciseGroups and exercises loaded
      * @return the list of student exams with their corresponding users
      */
-    @Transactional
+    @Transactional // TODO: NOT OK --> remove @Transactional
     public List<StudentExam> generateMissingStudentExams(Exam exam) {
 
         // Get all users who already have an individual exam

src/main/java/de/tum/in/www1/artemis/service/plagiarism/PlagiarismService.java

@@ -11,6 +11,7 @@
 import java.util.function.Predicate;
 import java.util.stream.Stream;
 
+import javax.annotation.Nullable;
 import javax.validation.constraints.NotNull;
 
 import org.springframework.context.annotation.Profile;
@@ -59,7 +60,7 @@ public PlagiarismService(PlagiarismComparisonRepository plagiarismComparisonRepo
      * @param userLogin       the user login of the student asking to see his plagiarism comparison.
      * @param exerciseDueDate due date of the exercise.
      */
-    public void checkAccessAndAnonymizeSubmissionForStudent(Submission submission, String userLogin, ZonedDateTime exerciseDueDate) {
+    public void checkAccessAndAnonymizeSubmissionForStudent(Submission submission, String userLogin, @Nullable ZonedDateTime exerciseDueDate) {
         if (!hasAccessToSubmission(submission.getId(), userLogin, exerciseDueDate)) {
             throw new AccessForbiddenException("This plagiarism submission is not related to the requesting user or the user has not been notified yet.");
         }
@@ -87,17 +88,18 @@ public boolean hasPlagiarismComparison(long submissionId) {
      * @param exerciseDueDate due date of the exercise.
      * @return true is the user has access to the submission
      */
-    public boolean hasAccessToSubmission(Long submissionId, String userLogin, ZonedDateTime exerciseDueDate) {
+    public boolean hasAccessToSubmission(Long submissionId, String userLogin, @Nullable ZonedDateTime exerciseDueDate) {
         var comparisonOptional = plagiarismComparisonRepository.findBySubmissionA_SubmissionIdOrSubmissionB_SubmissionId(submissionId, submissionId);
         return comparisonOptional.filter(not(Set::isEmpty)).isPresent()
                 && isOwnSubmissionOrIsAfterExerciseDueDate(submissionId, userLogin, comparisonOptional.get(), exerciseDueDate)
                 && wasUserNotifiedByInstructor(userLogin, comparisonOptional.get());
     }
 
-    private boolean isOwnSubmissionOrIsAfterExerciseDueDate(Long submissionId, String userLogin, Set<PlagiarismComparison<?>> comparisons, ZonedDateTime exerciseDueDate) {
+    private boolean isOwnSubmissionOrIsAfterExerciseDueDate(Long submissionId, String userLogin, Set<PlagiarismComparison<?>> comparisons,
+            @Nullable ZonedDateTime exerciseDueDate) {
         var isOwnSubmission = comparisons.stream().flatMap(it -> Stream.of(it.getSubmissionA(), it.getSubmissionB())).filter(Objects::nonNull)
                 .filter(it -> it.getSubmissionId() == submissionId).findFirst().map(PlagiarismSubmission::getStudentLogin).filter(isEqual(userLogin)).isPresent();
-        return isOwnSubmission || exerciseDueDate.isBefore(ZonedDateTime.now());
+        return isOwnSubmission || exerciseDueDate == null || exerciseDueDate.isBefore(ZonedDateTime.now());
     }
 
     /**

src/main/java/de/tum/in/www1/artemis/web/rest/TextSubmissionResource.java

@@ -153,6 +153,7 @@ public ResponseEntity<TextSubmission> getTextSubmissionWithResults(@PathVariable
         if (!authCheckService.isAtLeastTeachingAssistantForExercise(textSubmission.getParticipation().getExercise())) {
             // anonymize and throw exception if not authorized to view submission
             plagiarismService.checkAccessAndAnonymizeSubmissionForStudent(textSubmission, userRepository.getUser().getLogin(),
+                    // TODO: might be better to use the individual due date here if available
                     textSubmission.getParticipation().getExercise().getDueDate());
             return ResponseEntity.ok(textSubmission);
         }

src/test/java/de/tum/in/www1/artemis/repository/ProgrammingExerciseStudentParticipationTestRepository.java

@@ -20,7 +20,7 @@ public interface ProgrammingExerciseStudentParticipationTestRepository extends J
      *
      * @param buildPlanId new build plan id to be set
      */
-    @Transactional
+    @Transactional // ok because of modifying query
     @Modifying
     @Query("""
             UPDATE ProgrammingExerciseStudentParticipation p