initial impl

build.gradle.kts

@@ -8,7 +8,7 @@ version = "2.1.2"
 
 val javaVersion = JavaVersion.VERSION_17
 
-val libradorVersion = "1.2.1"
+val libradorVersion = "1.2.2"
 val labradoorVersion = "1.3.5"
 val queryDslVersion = "4.4.0"
 

src/main/java/nl/tudelft/queue/controller/AdminController.java

@@ -129,11 +129,11 @@ public class AdminController {
 	@GetMapping("/running")
 	public String getRunningLabs(Model model) {
 		LocalDateTime now = LocalDateTime.now();
-		var runningEditions = eCache.get(Objects.requireNonNull(
+		var runningEditions = eCache.getAndIgnoreMissing(Objects.requireNonNull(
 				eApi.getAllEditionsActiveAtDate(LocalDateTime.now())
 						.map(EditionSummaryDTO::getId).collectList().block()));
 
-		var runningSessions = sCache.get(runningEditions.stream()
+		var runningSessions = sCache.getAndIgnoreMissing(runningEditions.stream()
 				.flatMap(e -> e.getSessions().stream())
 				.filter(s -> s.getEnd().isAfter(now))
 				.map(SessionSummaryDTO::getId));

src/main/java/nl/tudelft/queue/controller/EditionController.java

@@ -29,6 +29,7 @@ import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
 import javax.servlet.http.HttpServletResponse;
+import javax.transaction.Transactional;
 import javax.validation.Valid;
 
 import nl.tudelft.labracore.api.*;
@@ -48,11 +49,7 @@ import nl.tudelft.queue.model.LabRequest;
 import nl.tudelft.queue.model.enums.QueueSessionType;
 import nl.tudelft.queue.model.labs.Lab;
 import nl.tudelft.queue.repository.QueueSessionRepository;
-import nl.tudelft.queue.service.EditionService;
-import nl.tudelft.queue.service.EditionStatusService;
-import nl.tudelft.queue.service.PermissionService;
-import nl.tudelft.queue.service.QuestionService;
-import nl.tudelft.queue.service.RoleDTOService;
+import nl.tudelft.queue.service.*;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.core.io.Resource;
@@ -141,6 +138,9 @@ public class EditionController {
 	@Autowired
 	private QuestionService qs;
 
+	@Autowired
+	private LabService ls;
+
 	/**
 	 * Gets the page listing all editions. This page incorporates pageables to index many different editions
 	 * and keep the overview small.
@@ -164,7 +164,8 @@ public class EditionController {
 				.block();
 
 		eCache.register(editions.getContent());
-		erCache.get(editions.getContent().stream().map(EditionDetailsDTO::getId));
+
+		erCache.getAndIgnoreMissing(editions.getContent().stream().map(EditionDetailsDTO::getId));
 
 		model.addAttribute("editions",
 				new PageImpl<>(editions.getContent(), pageable, editions.getTotalElements()));
@@ -224,7 +225,7 @@ public class EditionController {
 		if (!ps.canEnrolForEdition(editionId)) {
 			return "redirect:/editions";
 		}
-		model.addAttribute("edition", eCache.getOrThrow(editionId));
+		model.addAttribute("edition", eCache.getRequired(editionId));
 
 		return "edition/enrol";
 	}
@@ -256,7 +257,7 @@ public class EditionController {
 	 */
 	@GetMapping("/edition/{editionId}")
 	public String getEditionView(@PathVariable Long editionId, Model model) {
-		model.addAttribute("edition", eCache.getOrThrow(editionId));
+		model.addAttribute("edition", eCache.getRequired(editionId));
 
 		return "edition/view/info";
 	}
@@ -274,7 +275,7 @@ public class EditionController {
 	public String getEditionParticipantsView(@PathVariable Long editionId, Model model,
 			@RequestParam(value = "student-search", required = false) String studentSearch,
 			@PageableDefault(size = 25) Pageable pageable) {
-		var edition = eCache.getOrThrow(editionId);
+		var edition = eCache.getRequired(editionId);
 		var students = roleDTOService.students(edition);
 
 		if (studentSearch != null) {
@@ -299,8 +300,8 @@ public class EditionController {
 	@GetMapping("/edition/{editionId}/modules")
 	@PreAuthorize("@permissionService.canViewEdition(#editionId)")
 	public String getEditionModulesView(@PathVariable Long editionId, Model model) {
-		var edition = eCache.getOrThrow(editionId);
-		var modules = mCache.get(edition.getModules().stream().map(ModuleSummaryDTO::getId));
+		var edition = eCache.getRequired(editionId);
+		var modules = mCache.getAndIgnoreMissing(edition.getModules().stream().map(ModuleSummaryDTO::getId));
 
 		modules.sort(Comparator.comparing(ModuleDetailsDTO::getName));
 		modules.forEach(m -> {
@@ -308,14 +309,14 @@ public class EditionController {
 			m.getAssignments().sort(Comparator.comparing(AssignmentSummaryDTO::getName));
 		});
 
-		sgCache.get(modules.stream()
+		sgCache.getAndIgnoreMissing(modules.stream()
 				.flatMap(m -> m.getGroups().stream().map(StudentGroupSmallSummaryDTO::getId)));
 
 		model.addAttribute("edition", edition);
 		model.addAttribute("modules", modules);
 		model.addAttribute("groups", modules.stream()
 				.collect(Collectors.toMap(ModuleDetailsDTO::getId,
-						m -> sgCache.get(m.getGroups().stream().map(StudentGroupSmallSummaryDTO::getId)))));
+						m -> sgCache.getAndIgnoreMissing(m.getGroups().stream().map(StudentGroupSmallSummaryDTO::getId)))));
 
 		return "edition/view/modules";
 	}
@@ -331,15 +332,17 @@ public class EditionController {
 	 */
 	@GetMapping("/edition/{editionId}/labs")
 	@PreAuthorize("@permissionService.canViewEdition(#editionId)")
+	@Transactional
 	public String getEditionSessionsView(@PathVariable Long editionId,
 			@RequestParam(required = false, defaultValue = "") List<QueueSessionType> queueSessionTypes,
 			@RequestParam(required = false, defaultValue = "") List<Long> modules,
 			Model model) {
-		var edition = eCache.getOrThrow(editionId);
+		var edition = eCache.getRequired(editionId);
 
 		// Make sure that session details are cached.
-		var sessions = sCache.get(edition.getSessions().stream()
-				.map(SessionSummaryDTO::getId));
+		var sessions = sCache.getAndHandleAll(edition.getSessions().stream()
+				.map(SessionSummaryDTO::getId), ls.deleteSessionsByIds());
+		
 
 		// Find all labs from the sessions, convert to summaries, and filter.
 		var labs = es.filterLabs(
@@ -369,7 +372,7 @@ public class EditionController {
 	@GetMapping("/edition/{editionId}/questions")
 	@PreAuthorize("@permissionService.canManageQuestions(#editionId)")
 	public String getEditionQuestions(@PathVariable Long editionId, Model model) {
-		model.addAttribute("edition", eCache.getOrThrow(editionId));
+		model.addAttribute("edition", eCache.getRequired(editionId));
 		model.addAttribute("questions", qApi.getQuestionsByEdition(editionId).collectList().block());
 
 		return "edition/view/questions";
@@ -385,7 +388,7 @@ public class EditionController {
 	@GetMapping("/edition/{editionId}/participants/create")
 	@PreAuthorize("@permissionService.canManageParticipants(#editionId)")
 	public String getAddParticipantPage(@PathVariable Long editionId, Model model) {
-		model.addAttribute("edition", eCache.getOrThrow(editionId));
+		model.addAttribute("edition", eCache.getRequired(editionId));
 		model.addAttribute("role", new QueueRoleCreateDTO(editionId));
 
 		return "edition/create/participant";
@@ -407,7 +410,7 @@ public class EditionController {
 
 		RoleCreateDTO create = dto.apply();
 		if (dto.hasErrors()) {
-			model.addAttribute("edition", eCache.getOrThrow(editionId));
+			model.addAttribute("edition", eCache.getRequired(editionId));
 			model.addAttribute("role", dto);
 
 			return "edition/create/participant";
@@ -442,7 +445,7 @@ public class EditionController {
 	public String importParticipants(@PathVariable Long editionId,
 			@RequestParam("file") MultipartFile csv,
 			RedirectAttributes attributes) {
-		EditionDetailsDTO edition = eCache.getOrThrow(editionId);
+		EditionDetailsDTO edition = eCache.getRequired(editionId);
 
 		try {
 			es.addCourseParticipants(csv, edition);
@@ -467,10 +470,10 @@ public class EditionController {
 	@PreAuthorize("@permissionService.canManageParticipants(#editionId)")
 	public String getRemoveParticipantPage(@PathVariable Long editionId, @PathVariable Long personId,
 			Model model) {
-		EditionDetailsDTO edition = eCache.getOrThrow(editionId);
+		EditionDetailsDTO edition = eCache.getRequired(editionId);
 
 		model.addAttribute("edition", edition);
-		model.addAttribute("role", rCache.getOrThrow(new Id()
+		model.addAttribute("role", rCache.getRequired(new Id()
 				.personId(personId).editionId(editionId)));
 
 		return "edition/remove/participant";
@@ -517,7 +520,7 @@ public class EditionController {
 	@PreAuthorize("@permissionService.canLeaveEdition(#editionId)")
 	public String getParticipantLeavePage(@PathVariable Long editionId,
 			Model model) {
-		model.addAttribute("edition", eCache.getOrThrow(editionId));
+		model.addAttribute("edition", eCache.getRequired(editionId));
 
 		return "edition/view/leave";
 	}
@@ -549,10 +552,12 @@ public class EditionController {
 	 */
 	@GetMapping("/edition/{editionId}/status")
 	@PreAuthorize("@permissionService.canViewEditionStatus(#editionId)")
+	@Transactional
 	public String status(@PathVariable Long editionId,
 			Model model) {
-		var edition = eCache.getOrThrow(editionId);
-		var sessions = sCache.get(edition.getSessions().stream().map(SessionSummaryDTO::getId));
+		var edition = eCache.getRequired(editionId);
+		var sessions = sCache.getAndHandleAll(edition.getSessions().stream().map(SessionSummaryDTO::getId), ls.deleteSessionsByIds());
+
 
 		model.addAttribute("edition", edition);
 
@@ -561,9 +566,9 @@ public class EditionController {
 		model.addAttribute("inactiveLabs", getLabSummariesFromSessions(
 				sessions, s -> !(s.getStart().isBefore(now()) && now().isBefore(s.getEnd()))));
 
-		model.addAttribute("assignments", aCache.get(sessions.stream()
+		model.addAttribute("assignments", aCache.getAndIgnoreMissing(sessions.stream()
 				.flatMap(s -> s.getAssignments().stream().map(AssignmentSummaryDTO::getId)).distinct()));
-		model.addAttribute("rooms", rmCache.get(sessions.stream()
+		model.addAttribute("rooms", rmCache.getAndIgnoreMissing(sessions.stream()
 				.flatMap(s -> s.getRooms().stream().map(RoomDetailsDTO::getId)).distinct()));
 
 		return "edition/view/status";
@@ -666,7 +671,7 @@ public class EditionController {
 	@PreAuthorize("@permissionService.canManageQuestions(#editionId)")
 	public String getEditQuestionPage(@PathVariable Long editionId, @PathVariable Long questionId,
 			Model model) {
-		EditionDetailsDTO edition = eCache.getOrThrow(editionId);
+		EditionDetailsDTO edition = eCache.getRequired(editionId);
 
 		model.addAttribute("edition", edition);
 		model.addAttribute("question", qApi.getQuestionById(questionId).block());
@@ -708,7 +713,7 @@ public class EditionController {
 	@PreAuthorize("@permissionService.canManageQuestions(#editionId)")
 	public String getDeleteQuestionPage(@PathVariable Long editionId, @PathVariable Long questionId,
 			Model model) {
-		EditionDetailsDTO edition = eCache.getOrThrow(editionId);
+		EditionDetailsDTO edition = eCache.getRequired(editionId);
 
 		model.addAttribute("edition", edition);
 		model.addAttribute("question", qApi.getQuestionById(questionId).block());

src/main/java/nl/tudelft/queue/controller/HistoryController.java

@@ -34,6 +34,7 @@ import nl.tudelft.queue.cache.PersonCacheManager;
 import nl.tudelft.queue.cache.SessionCacheManager;
 import nl.tudelft.queue.repository.LabRequestRepository;
 import nl.tudelft.queue.repository.QueueSessionRepository;
+import nl.tudelft.queue.service.LabService;
 import nl.tudelft.queue.service.RequestTableService;
 
 import org.springframework.beans.factory.annotation.Autowired;
@@ -46,6 +47,8 @@ import org.springframework.ui.Model;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 
+import javax.transaction.Transactional;
+
 @Controller
 public class HistoryController {
 
@@ -76,6 +79,9 @@ public class HistoryController {
 	@Autowired
 	private RequestTableService rts;
 
+	@Autowired
+	private LabService ls;
+
 	/**
 	 * Gets the view representing the request history of the currently authenticated student.
 	 *
@@ -111,14 +117,14 @@ public class HistoryController {
 			@PathVariable Long editionId,
 			@PathVariable Long studentId,
 			@PageableDefault(sort = "createdAt", direction = Sort.Direction.DESC, size = 25) Pageable pageable) {
-		var edition = eCache.getOrThrow(editionId);
+		var edition = eCache.getRequired(editionId);
 
 		List<Long> groups = sgApi.getGroupsForPersonAndCourse(studentId, edition.getCourse().getId())
 				.map(StudentGroupSummaryDTO::getId)
 				.collectList().block();
 
 		model.addAttribute("edition", edition);
-		model.addAttribute("student", pCache.getOrThrow(studentId));
+		model.addAttribute("student", pCache.getRequired(studentId));
 
 		setHistoryModel("/history/edition/" + editionId + "/student/" + studentId,
 				model, studentId, groups, pageable);
@@ -136,18 +142,21 @@ public class HistoryController {
 	 * @param groupIds The ids of the groups to find requests for.
 	 * @param pageable The pageable containing the information on the page to show.
 	 */
-	private void setHistoryModel(String key, Model model, Long studentId, List<Long> groupIds,
+	@Transactional
+	public void setHistoryModel(String key, Model model, Long studentId, List<Long> groupIds,
 								Pageable pageable) {
-		var editions = eCache.get(pApi.getRolesForPerson(studentId)
+		var editions = eCache.getAndIgnoreMissing(pApi.getRolesForPerson(studentId)
 				.filter(r -> r.getType() == RoleEditionDetailsDTO.TypeEnum.STUDENT)
 				.map(r -> r.getEdition().getId())
 				.toStream());
-		erCache.get(editions.stream().map(EditionDetailsDTO::getId));
+
+		erCache.getAndIgnoreMissing(editions.stream().map(EditionDetailsDTO::getId));
 
 		var sessionIds = editions.stream()
 				.flatMap(e -> e.getSessions().stream().map(SessionSummaryDTO::getId))
 				.collect(Collectors.toList());
-		sCache.get(sessionIds);
+
+		sCache.getAndHandleAll(sessionIds, ls.deleteSessionsByIds());
 
 		var labs = qsr.findAllBySessions(sessionIds);
 

src/main/java/nl/tudelft/queue/controller/HomeController.java

@@ -171,17 +171,17 @@ public class HomeController {
 							Set.of(TEACHER_RO).contains(role.getType()))
 					.collect(Collectors.toList());
 
-			var editions = eCache.get(roles.stream().map(r -> r.getEdition().getId()))
+			var editions = eCache.getAndIgnoreMissing(roles.stream().map(r -> r.getEdition().getId()))
 					.stream()
 					.collect(Collectors.toMap(EditionDetailsDTO::getId, Function.identity()));
 
-			Set<SessionDetailsDTO> sessions = new HashSet<>(sCache.get(editions.values().stream()
+			Set<SessionDetailsDTO> sessions = new HashSet<>(sCache.getAndHandleAll(editions.values().stream()
 					.flatMap(e -> e.getSessions().stream())
 					.filter(s -> s.getEnd().isAfter(now.minusMonths(1)))
-					.map(SessionSummaryDTO::getId)));
+					.map(SessionSummaryDTO::getId),missingIds -> ls.deleteSessionsByIds()));
 
 			var sharedEditions = editions.values().stream().map(EditionDetailsDTO::getEditionCollections)
-					.flatMap(List::stream).map(e -> ecCache.getOrThrow(e.getId()))
+					.flatMap(List::stream).map(e -> ecCache.getRequired(e.getId()))
 					.collect(Collectors.toSet());
 
 			var calendarEntries = ls.convertToCalendarEntries(
@@ -198,7 +198,7 @@ public class HomeController {
 			var sharedLabs = sharedEditions.stream().collect(Collectors.toMap(
 					EditionCollectionDetailsDTO::getId,
 					s -> es.sortLabs(View.convert(new ArrayList<>(lr.findAllBySessions(
-							eCache.get(s.getEditions().stream().map(EditionSummaryDTO::getId).toList())
+							eCache.getAndIgnoreMissing(s.getEditions().stream().map(EditionSummaryDTO::getId).toList())
 									.stream().map(EditionDetailsDTO::getSessions).flatMap(List::stream)
 									.map(SessionSummaryDTO::getId).collect(Collectors.toList()))),
 							QueueSessionSummaryDTO.class)).stream()
@@ -207,7 +207,7 @@ public class HomeController {
 							.collect(Collectors.toList())));
 
 			if (pd.getDefaultRole() == ADMIN || pd.getDefaultRole() == TEACHER) {
-				model.addAttribute("allEditions", eCache.get(
+				model.addAttribute("allEditions", eCache.getAndIgnoreMissing(
 						Objects.requireNonNullElse(
 								eApi.getAllEditionsActiveDuringPeriod(
 										new Period().start(LocalDateTime.now())
@@ -280,7 +280,7 @@ public class HomeController {
 	 * @param pageable    The pageable containing information on how much feedback needs to be shown.
 	 */
 	private void fillInFeedbackModel(Long assistantId, Person person, Model model, Pageable pageable) {
-		var assistant = pCache.getOrThrow(assistantId);
+		var assistant = pCache.getRequired(assistantId);
 
 		Page<Feedback> feedback = assistantId.equals(person.getId())
 				? fr.findByAssistantAnonymised(assistantId, pageable)

src/main/java/nl/tudelft/queue/controller/LabController.java

@@ -165,7 +165,7 @@ public class LabController {
 					.ifPresent(r -> model.addAttribute("selectionResult", r.toViewDTO()));
 		}
 
-		model.addAttribute("modules", mCache.get(qSession.getModules().stream()));
+		model.addAttribute("modules", mCache.getAndIgnoreMissing(qSession.getModules().stream()));
 
 		return "lab/view/" + qSession.getType().name().toLowerCase();
 	}
@@ -233,7 +233,7 @@ public class LabController {
 			Model model) {
 		setEnqueuePageAttributes(lab, model, person);
 
-		model.addAttribute("assignment", aCache.getOrThrow(assignment));
+		model.addAttribute("assignment", aCache.getRequired(assignment));
 
 		return "lab/question";
 	}
@@ -254,7 +254,7 @@ public class LabController {
 			Model model) {
 		setEnqueuePageAttributes(lab, model, person);
 
-		model.addAttribute("assignment", aCache.getOrThrow(assignment));
+		model.addAttribute("assignment", aCache.getRequired(assignment));
 		model.addAttribute("question", question);
 		model.addAttribute("request", new LabRequestCreateDTO());
 		model.addAttribute("rType", "lab");
@@ -357,7 +357,7 @@ public class LabController {
 	public String getLabCreateView(@PathVariable Long editionId,
 			@RequestParam QueueSessionType type, Model model) {
 		model.addAttribute("dto", type.newCreateDto());
-		model.addAttribute("edition", eCache.getOrThrow(editionId));
+		model.addAttribute("edition", eCache.getRequired(editionId));
 		model.addAttribute("lType", type);
 
 		setSessionEditingPageAttributes(List.of(editionId), model);
@@ -377,7 +377,7 @@ public class LabController {
 	@PreAuthorize("@permissionService.canManageSharedSessions(#editionCollectionId)")
 	public String getSharedLabCreateView(@PathVariable Long editionCollectionId,
 			@RequestParam QueueSessionType type, Model model) {
-		var editionCollection = ecCache.getOrThrow(editionCollectionId);
+		var editionCollection = ecCache.getRequired(editionCollectionId);
 
 		model.addAttribute("dto", type.newCreateDto());
 		model.addAttribute("ec", editionCollection);
@@ -529,7 +529,7 @@ public class LabController {
 	@PreAuthorize("@permissionService.canManageSession(#qSession)")
 	public String deleteSession(@PathEntity QueueSession<?> qSession) {
 		ls.deleteSession(qSession);
-		var session = sCache.getOrThrow(qSession.getSession());
+		var session = sCache.getRequired(qSession.getSession(), id -> ls.deleteSession(qSession));
 
 		if (session.getEditionCollection() != null) {
 			return "redirect:/shared-edition/" + session.getEditionCollection().getId();
@@ -550,7 +550,7 @@ public class LabController {
 	@PreAuthorize("@permissionService.canManageSession(#qSession)")
 	public String getLabCopyView(@PathEntity QueueSession<?> qSession,
 			Model model) {
-		var session = sCache.getOrThrow(qSession.getSession());
+		var session = sCache.getRequired(qSession.getSession(), id -> ls.deleteSession(qSession));
 
 		model.addAttribute("dto", qSession.copyLabCreateDTO(session));
 		model.addAttribute("lType", qSession.getType());
@@ -688,8 +688,9 @@ public class LabController {
 	 * @param model    The model to fill using edition and lab information.
 	 * @param person   The person used to fill in the information.
 	 */
-	private void setEnqueuePageAttributes(QueueSession<?> qSession, Model model, Person person) {
-		var session = sCache.getOrThrow(qSession.getSession());
+	@Transactional
+	public void setEnqueuePageAttributes(QueueSession<?> qSession, Model model, Person person) {
+		var session = sCache.getRequired(qSession.getSession(), id -> ls.deleteSession(qSession));
 		session.getRooms().sort(Comparator.comparing(r -> r.getBuilding().getName() + r.getName()));
 
 		model.addAttribute("qSession", qSession.toViewDTO());
@@ -701,26 +702,26 @@ public class LabController {
 			var lab = (Lab) qSession;
 			var isStaffInAll = session.getEditions().stream().allMatch(e -> roleService
 					.rolesForPersonInEdition(e, person).stream().allMatch(roleService::isStaff));
-			List<AssignmentDetailsDTO> allowedAssignments = aCache.get(lab.getAllowedRequests().stream()
-					.map(AllowedRequest::getAssignment).distinct().collect(Collectors.toList()))
+			List<AssignmentDetailsDTO> allowedAssignments = aCache.getAndHandleAll(lab.getAllowedRequests().stream()
+					.map(AllowedRequest::getAssignment).distinct().collect(Collectors.toList()), assignmentIds -> lab.getAllowedRequests().removeIf(a -> assignmentIds.contains(a.getAssignment())))
 					.stream().filter(a -> {
-						var edition = mCache.getOrThrow(a.getModule().getId()).getEdition();
+						var edition = mCache.getRequired(a.getModule().getId()).getEdition();
 						return isStaffInAll || roleService.rolesForPersonInEdition(edition, person).stream()
 								.noneMatch(roleService::isStaff);
 					}).toList();
 			Map<Long, String> assignments = allowedAssignments.stream()
 					.collect(Collectors.toMap(AssignmentDetailsDTO::getId, a -> {
-						var edition = mCache.getOrThrow(a.getModule().getId()).getEdition();
+						var edition = mCache.getRequired(a.getModule().getId()).getEdition();
 						return session.getEditions().size() == 1
 								? a.getName()
-								: eCache.getOrThrow(edition.getId()).getCourse().getName() + " - "
+								: eCache.getRequired(edition.getId()).getCourse().getName() + " - "
 										+ a.getName();
 					}));
 			Map<Long, Long> notEnqueueAble = allowedAssignments.stream().filter(a -> {
-				var edition = mCache.getOrThrow(a.getModule().getId()).getEdition();
+				var edition = mCache.getRequired(a.getModule().getId()).getEdition();
 				return roleService.rolesForPersonInEdition(edition, person).isEmpty();
 			}).collect(Collectors.toMap(AssignmentDetailsDTO::getId, a -> {
-				var edition = mCache.getOrThrow(a.getModule().getId()).getEdition();
+				var edition = mCache.getRequired(a.getModule().getId()).getEdition();
 				return edition.getId();
 			}));
 
@@ -730,7 +731,7 @@ public class LabController {
 					.collect(Collectors.groupingBy(AllowedRequest::getAssignment,
 							Collectors.mapping(ar -> ar.getType().displayName(), Collectors.toSet()))));
 		} else {
-			model.addAttribute("modules", mCache.get(qSession.getModules().stream())
+			model.addAttribute("modules", mCache.getAndHandle(qSession.getModules().stream(), moduleID -> qSession.getModules().remove(moduleID))
 					.stream().sorted(Comparator.comparing(ModuleDetailsDTO::getName))
 					.collect(Collectors.toList()));
 		}
@@ -743,14 +744,14 @@ public class LabController {
 	 * @param model      The model to fill using edition information.
 	 */
 	private void setSessionEditingPageAttributes(List<Long> editionIds, Model model) {
-		var editions = eCache.get(editionIds);
+		var editions = eCache.getAndIgnoreMissing(editionIds);
 
-		var modules = mCache.get(editions.stream()
+		var modules = mCache.getAndIgnoreMissing(editions.stream()
 				.flatMap(e -> e.getModules().stream().map(ModuleSummaryDTO::getId).distinct()));
-		var assignments = aCache.get(modules.stream()
+		var assignments = aCache.getAndIgnoreMissing(modules.stream()
 				.flatMap(m -> m.getAssignments().stream().map(AssignmentSummaryDTO::getId)).distinct());
 		var clusters = cCache
-				.get(editions.stream().map(e -> e.getCohort().getId()).distinct())
+				.getAndIgnoreMissing(editions.stream().map(e -> e.getCohort().getId()).distinct())
 				.stream().flatMap(cohort -> cohort.getClusters().stream()).distinct()
 				.sorted(Comparator.comparing(ClusterSummaryDTO::getName)).collect(Collectors.toList());
 
@@ -787,13 +788,13 @@ public class LabController {
 	 * @param model    The model to fill using lab information.
 	 */
 	private void setSessionEditingPageAttributes(QueueSession<?> qSession, Model model) {
-		var session = sCache.getOrThrow(qSession.getSession());
+		var session = sCache.getRequired(qSession.getSession(), id -> ls.deleteSession(qSession));
 		model.addAttribute("lSession", session);
 
 		if (session.getEdition() != null) {
-			model.addAttribute("edition", eCache.getOrThrow(session.getEdition().getId()));
+			model.addAttribute("edition", eCache.getRequired(session.getEdition().getId()));
 		} else {
-			model.addAttribute("ec", ecCache.getOrThrow(session.getEditionCollection().getId()));
+			model.addAttribute("ec", ecCache.getRequired(session.getEditionCollection().getId()));
 		}
 
 		setSessionEditingPageAttributes(session.getEditions().stream()
@@ -813,7 +814,7 @@ public class LabController {
 		Matcher matcher = testPattern.matcher(request.getRequestURI());
 		if (matcher.matches() && matcher.groupCount() == 1) {
 			Optional<QueueSession<?>> lab = qsRepository.findById(Long.parseLong(matcher.group(1)));
-			var session = sCache.getOrThrow(lab.orElseThrow().getSession());
+			var session = sCache.getRequired(lab.orElseThrow().getSession(), id -> ls.deleteSession(lab.get()));
 			var edition = session.getEdition().getId();
 			return "redirect:/edition/" + edition + "/enrol";
 		}

src/main/java/nl/tudelft/queue/controller/ModuleController.java

@@ -131,7 +131,7 @@ public class ModuleController {
 	 * @return           The Thymeleaf template to resolve.
 	 */
 	private String addCreateModuleAttributes(Long editionId, QueueModuleCreateDTO dto, Model model) {
-		EditionDetailsDTO edition = eCache.getOrThrow(editionId);
+		EditionDetailsDTO edition = eCache.getRequired(editionId);
 
 		model.addAttribute("edition", edition);
 		model.addAttribute("dto", dto);

src/main/java/nl/tudelft/queue/dto/create/requests/LabRequestCreateDTO.java

@@ -80,7 +80,7 @@ public class LabRequestCreateDTO extends RequestCreateDTO<LabRequest, Lab> {
 			errors.rejectValue("onlineMode", "Room or online mode not selected");
 		}
 
-		var session = getBean(SessionCacheManager.class).getOrThrow(this.getSession().getSession());
+		var session = getBean(SessionCacheManager.class).getRequired(this.getSession().getSession());
 		if (room != null && session.getRooms().stream().noneMatch(r -> Objects.equals(r.getId(), room))) {
 			errors.rejectValue("room", "A room with id " + room + " is not available in the lab.");
 		}
@@ -99,7 +99,7 @@ public class LabRequestCreateDTO extends RequestCreateDTO<LabRequest, Lab> {
 
 	@Override
 	public Long getModule() {
-		return getBean(AssignmentCacheManager.class).getOrThrow(assignment)
+		return getBean(AssignmentCacheManager.class).getRequired(assignment)
 				.getModule().getId();
 	}
 

src/main/java/nl/tudelft/queue/dto/view/ExamRequestViewDTO.java

@@ -43,6 +43,6 @@ public class ExamRequestViewDTO extends View<LabRequest> {
 	public void postApply() {
 		super.postApply();
 
-		requesterName = getBean(PersonCacheManager.class).getOrThrow(data.getRequester()).getDisplayName();
+		requesterName = getBean(PersonCacheManager.class).getRequired(data.getRequester()).getDisplayName();
 	}
 }

src/main/java/nl/tudelft/queue/dto/view/ExamTimeSlotViewDTO.java

@@ -58,7 +58,7 @@ public class ExamTimeSlotViewDTO extends View<ClosableTimeSlot> {
 		handled = data.countHandledRequests();
 
 		// Ensure caching of exam request people and then get exam request views
-		getBean(PersonCacheManager.class).get(data.getRequests().stream().map(LabRequest::getRequester));
+		getBean(PersonCacheManager.class).getAndIgnoreMissing(data.getRequests().stream().map(LabRequest::getRequester));
 		examRequests = View.convert(new ArrayList<>(data.getRequests()), ExamRequestViewDTO.class);
 	}
 

src/main/java/nl/tudelft/queue/dto/view/FeedbackViewDTO.java

@@ -65,7 +65,7 @@ public class FeedbackViewDTO extends View<Feedback> {
 	}
 
 	private String editionName(Long sessionId) {
-		var session = getBean(SessionCacheManager.class).getOrThrow(sessionId);
+		var session = getBean(SessionCacheManager.class).getRequired(sessionId);
 
 		return (session.getEdition() == null) ? session.getEditionCollection().getName()
 				: session.getEdition().getName();
@@ -91,7 +91,7 @@ public class FeedbackViewDTO extends View<Feedback> {
 	 * @return The name of the requesting entity (either the group or the student).
 	 */
 	private String requesterEntityName(Long studentGroupId) {
-		var studentGroup = getBean(StudentGroupCacheManager.class).getOrThrow(studentGroupId);
+		var studentGroup = getBean(StudentGroupCacheManager.class).getRequired(studentGroupId);
 		if (studentGroup.getMemberUsernames().size() == 1) {
 			return studentGroup.getMembers().get(0).getPerson().getDisplayName();
 		} else {

src/main/java/nl/tudelft/queue/dto/view/requests/LabRequestViewDTO.java

@@ -72,13 +72,13 @@ public class LabRequestViewDTO extends RequestViewDTO<LabRequest> {
 			setRoom(null);
 		}
 
-		assignment = getBean(AssignmentCacheManager.class).getOrThrow(data.getAssignment());
+		assignment = getBean(AssignmentCacheManager.class).getRequired(data.getAssignment());
 		timeSlot = data.getTimeSlot();
 
 		if (super.getEdition() == null) {
-			var editionId = getBean(ModuleCacheManager.class).getOrThrow(assignment.getModule().getId())
+			var editionId = getBean(ModuleCacheManager.class).getRequired(assignment.getModule().getId())
 					.getEdition().getId();
-			super.setEdition(getBean(EditionCacheManager.class).getOrThrow(editionId));
+			super.setEdition(getBean(EditionCacheManager.class).getRequired(editionId));
 		}
 
 		var handledEvent = getEvents().stream()

src/main/java/nl/tudelft/queue/model/constraints/ClusterConstraint.java

@@ -26,6 +26,7 @@ import java.util.stream.Collectors;
 import javax.persistence.ElementCollection;
 import javax.persistence.Entity;
 import javax.persistence.OneToOne;
+import javax.transaction.Transactional;
 import javax.validation.constraints.NotNull;
 
 import lombok.AllArgsConstructor;
@@ -40,6 +41,8 @@ import nl.tudelft.queue.dto.create.constraints.ClusterConstraintCreateDTO;
 import nl.tudelft.queue.model.LabRequestConstraint;
 import nl.tudelft.queue.model.QueueSession;
 
+import static nl.tudelft.librador.SpringContext.getBean;
+
 @Data
 @Entity
 @SuperBuilder
@@ -62,11 +65,12 @@ public class ClusterConstraint extends LabRequestConstraint {
 	private QueueSession<?> session;
 
 	@Override
+	@Transactional
 	public boolean canCreateRequest(Long personId) {
 		// Get the clusters in the list of allowed clusters and check whether the person is in one of these.
 		// TODO: Optimize this by creating a method for getting cluster ids per person.
-		return SpringContext.getBean(ClusterCacheManager.class)
-				.get(clusters.stream()).stream()
+		return getBean(ClusterCacheManager.class)
+				.getAndHandle(clusters.stream(), clusterID -> this.clusters.remove(clusterID)).stream()
 				.anyMatch(cluster -> cluster.getPeople().stream()
 						.anyMatch(person -> Objects.equals(person.getId(), personId)));
 	}
@@ -78,7 +82,7 @@ public class ClusterConstraint extends LabRequestConstraint {
 
 	@Override
 	public String constraintDescription() {
-		return "in cluster " + SpringContext.getBean(ClusterCacheManager.class).get(new ArrayList<>(clusters))
+		return "in cluster " + getBean(ClusterCacheManager.class).getAndIgnoreMissing(new ArrayList<>(clusters))
 				.stream().map(ClusterDetailsDTO::getName).collect(Collectors.joining(", "));
 	}
 

src/main/java/nl/tudelft/queue/model/labs/CapacitySession.java

@@ -45,6 +45,8 @@ import nl.tudelft.queue.model.Request;
 import nl.tudelft.queue.model.SelectionRequest;
 import nl.tudelft.queue.model.embeddables.CapacitySessionConfig;
 import nl.tudelft.queue.model.enums.QueueSessionType;
+import nl.tudelft.queue.service.LabService;
+import org.apache.groovy.parser.antlr4.GroovyParser;
 
 @Data
 @Entity
@@ -65,7 +67,7 @@ public class CapacitySession extends QueueSession<SelectionRequest> {
 
 	@Override
 	public boolean allowsRequest(Request<?> request) {
-		var session = getBean(SessionCacheManager.class).get(getSession());
+		var session = getBean(SessionCacheManager.class).getRequired(getSession(), id -> getBean(LabService.class).deleteSession(this));
 
 		boolean allowed = request instanceof SelectionRequest && super.allowsRequest(request);
 		if (capacitySessionConfig.getProcedure().isFcfs()) {

src/main/java/nl/tudelft/queue/model/labs/Lab.java

@@ -44,7 +44,10 @@ import nl.tudelft.queue.model.enums.CommunicationMethod;
 import nl.tudelft.queue.model.enums.OnlineMode;
 import nl.tudelft.queue.model.enums.RequestType;
 
+import nl.tudelft.queue.service.LabService;
 import org.hibernate.validator.constraints.UniqueElements;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.server.ResponseStatusException;
 
 @Data
 @Entity
@@ -134,7 +137,12 @@ public abstract class Lab extends QueueSession<LabRequest> {
 
 	@Override
 	public boolean allowsRequest(Request<?> request) {
-		var session = getBean(SessionCacheManager.class).getOrThrow(getSession());
+
+		var session = getBean(SessionCacheManager.class).get(getSession())
+				.orElseThrow(() -> {
+					getBean(LabService.class).deleteSession(this);
+					return new ResponseStatusException(HttpStatus.NOT_FOUND, "Session" + getSession() + "was deleted in the meantime");
+				});
 
 		return request instanceof LabRequest && super.allowsRequest(request)
 				&& allowsRequest((LabRequest) request)

src/main/java/nl/tudelft/queue/repository/QueueSessionRepository.java

@@ -19,6 +19,7 @@ package nl.tudelft.queue.repository;
 
 import java.util.List;
 
+import lombok.Builder;
 import nl.tudelft.queue.model.QQueueSession;
 import nl.tudelft.queue.model.QueueSession;
 

src/main/java/nl/tudelft/queue/service/CapacitySessionService.java

@@ -63,6 +63,9 @@ public class CapacitySessionService {
 	@Autowired
 	private PersonCacheManager pCache;
 
+	@Autowired
+	private LabService ls;
+
 	private SessionCacheManager sCache;
 
 	private StudentGroupCacheManager sgCache;
@@ -74,7 +77,7 @@ public class CapacitySessionService {
 	 * @return      The number of students in the group.
 	 */
 	private int countStudentMembers(Long sgId) {
-		return (int) sgCache.getOrThrow(sgId).getMembers().stream()
+		return (int) sgCache.getRequired(sgId).getMembers().stream()
 				.filter(role -> role.getType() == RolePersonLayer1DTO.TypeEnum.STUDENT)
 				.count();
 	}
@@ -245,7 +248,7 @@ public class CapacitySessionService {
 	 * @return                         The number of people that should be selected.
 	 */
 	private int getAmountToSelect(CapacitySession lab, List<SelectionRequest> alreadySelectedRequests) {
-		var session = sCache.getOrThrow(lab.getSession());
+		var session = sCache.getRequired(lab.getSession(), id -> ls.deleteSession(lab));
 
 		// Count the number of requests that have already been selected in case someone gets manually selected.
 		int countAlreadySelected = (int) alreadySelectedRequests.stream()
@@ -263,21 +266,6 @@ public class CapacitySessionService {
 		return amountToSelect;
 	}
 
-	/**
-	 * Initializes all caches that are used when running a selection. Pre-fetches all data required for a lab
-	 * so that no more fetched need to be done during the algorithm.
-	 *
-	 * @param labs The labs that selections will be run over.
-	 */
-	private void initializeCaches(List<CapacitySession> labs) {
-		sCache = new SessionCacheManager(sApi);
-		sgCache = new StudentGroupCacheManager(sgApi, pCache);
-
-		sCache.get(labs.stream().map(CapacitySession::getSession));
-		sgCache.get(labs.stream().flatMap(lab -> lab.getRequests().stream())
-				.map(SelectionRequest::getStudentGroup));
-	}
-
 	/**
 	 * Divides the given list of requests that were selected to come over the rooms that are available for the
 	 * lab automatically. Student groups are assigned to a room in the order in which they were selected until
@@ -288,7 +276,7 @@ public class CapacitySessionService {
 	 */
 	@Transactional
 	public void divideSelectedRequests(CapacitySession qSession, List<SelectionRequest> selectedRequests) {
-		var session = sCache.getOrThrow(qSession.getSession());
+		var session = sCache.getRequired(qSession.getSession(), id -> ls.deleteSession(qSession));
 
 		// For every room in the session, initialize a count
 		Map<RoomDetailsDTO, Integer> occupancy = new HashMap<>();
@@ -329,6 +317,22 @@ public class CapacitySessionService {
 		}
 	}
 
+	/**
+	 * Initializes all caches that are used when running a selection. Pre-fetches all data required for a lab
+	 * so that no more fetched need to be done during the algorithm.
+	 *
+	 * @param labs The labs that selections will be run over.
+	 */
+	@Transactional
+	public void initializeCaches(List<CapacitySession> labs) {
+		sCache = new SessionCacheManager(sApi);
+		sgCache = new StudentGroupCacheManager(sgApi, pCache);
+
+		sCache.getAndHandleAll(labs.stream().map(CapacitySession::getSession), ls.deleteSessionsByIds());
+		sgCache.getAndIgnoreMissing(labs.stream().flatMap(lab -> lab.getRequests().stream())
+				.map(SelectionRequest::getStudentGroup));
+	}
+
 	/**
 	 * Runs every minute on the 3rd second of the minute. This method finds all capacity-labs that have to
 	 * have their requests picked. For each of these labs, it selects students up to the capacity of the rooms
@@ -380,7 +384,7 @@ public class CapacitySessionService {
 		}
 		// If we have a fcfs lab we should select new students immediatly.
 		if (session.getCapacitySessionConfig().getProcedure().isFcfs()) {
-			for (RoomDetailsDTO room : sCache.getOrThrow(session.getSession()).getRooms()) {
+			for (RoomDetailsDTO room : sCache.getRequired(session.getSession(), id -> ls.deleteSession(session)).getRooms()) {
 				session.getRequests().stream()
 						.filter(selectionRequest -> !selectionRequest.getEventInfo().getStatus().isSelected())
 						.peek((r) -> r.setRoom(room.getId()))

src/main/java/nl/tudelft/queue/service/EditionStatusService.java

@@ -39,9 +39,12 @@ import nl.tudelft.queue.model.enums.RequestType;
 import nl.tudelft.queue.model.labs.Lab;
 import nl.tudelft.queue.repository.LabRequestRepository;
 
+import nl.tudelft.queue.repository.QueueSessionRepository;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
+import javax.transaction.Transactional;
+
 @Service
 public class EditionStatusService {
 	@Autowired
@@ -59,6 +62,11 @@ public class EditionStatusService {
 	@Autowired
 	private PersonCacheManager pCache;
 
+	@Autowired
+	private LabService ls;
+
+
+
 	/**
 	 * Creates the buckets used for counting frequencies of events occurring. Buckets are based on the minimum
 	 * time of day a lab in the given list of labs starts and the maximum time of day such a lab ends. The
@@ -74,9 +82,10 @@ public class EditionStatusService {
 	 * @param  nBuckets The number of buckets to create.
 	 * @return          A treeset of interval start times.
 	 */
+	@Transactional
 	public TreeSet<Long> createBucketsOverCourse(List<Lab> labs,
 			int nBuckets) {
-		var sessions = sCache.get(labs.stream().map(Lab::getSession));
+		var sessions = sCache.getAndHandleAll(labs.stream().map(Lab::getSession), ls.deleteSessionsByIds());
 
 		long min = sessions.stream()
 				.map(l -> l.getStart().getLong(SECOND_OF_DAY))
@@ -214,7 +223,7 @@ public class EditionStatusService {
 	 */
 	public Map<String, Long> countRequestsPerAssignment(List<Long> assignments,
 			List<LabRequest> requests) {
-		return aCache.get(assignments).stream()
+		return aCache.getAndIgnoreMissing(assignments).stream()
 				.collect(Collectors.toMap(
 						AssignmentDetailsDTO::getName,
 						a -> countWhere(requests, r -> r.getAssignment().equals(a.getId()))));
@@ -230,7 +239,7 @@ public class EditionStatusService {
 	 *                  occurs in the list of requests.
 	 */
 	public Map<String, Long> countRequestsPerRoom(List<Long> rooms, List<LabRequest> requests) {
-		return rCache.get(rooms).stream()
+		return rCache.getAndIgnoreMissing(rooms).stream()
 				.distinct()
 				.collect(Collectors.toMap(
 						RoomDetailsDTO::getName,
@@ -289,7 +298,7 @@ public class EditionStatusService {
 				.distinct()
 				.filter(Objects::nonNull)
 				.collect(Collectors.toList());
-		Map<Long, String> names = pCache.get(ids)
+		Map<Long, String> names = pCache.getAndIgnoreMissing(ids)
 				.stream()
 				.collect(Collectors.toMap(
 						PersonSummaryDTO::getId,

src/main/java/nl/tudelft/queue/service/FeedbackService.java

@@ -58,7 +58,7 @@ public class FeedbackService {
 	 *                   given request.
 	 */
 	public List<PersonSummaryDTO> assistantsInvolvedInRequest(Long requestId) {
-		return pCache.get(rr.findById(requestId).stream()
+		return pCache.getAndIgnoreMissing(rr.findById(requestId).stream()
 				.flatMap(request -> request.getEventInfo().involvedAssistants().stream()));
 	}
 

src/main/java/nl/tudelft/queue/service/JitsiService.java

@@ -49,7 +49,7 @@ public class JitsiService {
 		UUID uuid = UUID.randomUUID();
 
 		// Lookup the username of the requester and add it to the UUID to make a room name
-		return pCache.getOrThrow(request.getRequester()).getUsername() + "-" +
+		return pCache.getRequired(request.getRequester()).getUsername() + "-" +
 				uuid.toString().substring(0, 8);
 	}