Merge remote-tracking branch 'origin/dev-1.1.0' into development

Conflicts:
	src/main/java/ch/ethz/seb/sebserver/gui/content/MonitoringRunningExam.java
	src/main/java/ch/ethz/seb/sebserver/gui/service/page/impl/JitsiMeetProctoringView.java
	src/main/java/ch/ethz/seb/sebserver/gui/service/session/ProctoringGUIService.java
	src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/RemoteProctoringRoomDAO.java
	src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/impl/RemoteProctoringRoomDAOImpl.java
	src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/ExamProctoringRoomService.java
	src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/ExamProctoringRoomServiceImpl.java
	src/main/java/ch/ethz/seb/sebserver/webservice/weblayer/api/ExamProctoringController.java

src/main/java/ch/ethz/seb/sebserver/WebSecurityConfig.java

@@ -40,6 +40,9 @@ import ch.ethz.seb.sebserver.gbl.profile.WebServiceProfile;
 @Order(7)
 public class WebSecurityConfig extends WebSecurityConfigurerAdapter implements ErrorController {
 
+    private static final String ERROR_PATH = "/sebserver/error";
+    private static final String CHECK_PATH = "/sebserver/check";
+
     @Value("${sebserver.webservice.http.redirect.gui}")
     private String guiRedirect;
     @Value("${sebserver.webservice.api.exam.endpoint.discovery}")
@@ -78,22 +81,27 @@ public class WebSecurityConfig extends WebSecurityConfigurerAdapter implements E
     public void configure(final WebSecurity web) {
         web
                 .ignoring()
-                .antMatchers("/error")
+                .antMatchers(ERROR_PATH)
+                .antMatchers(CHECK_PATH)
                 .antMatchers(this.examAPIDiscoveryEndpoint)
                 .antMatchers(this.adminAPIEndpoint + API.INFO_ENDPOINT + API.LOGO_PATH_SEGMENT + "/**")
                 .antMatchers(this.adminAPIEndpoint + API.INFO_ENDPOINT + API.INFO_INST_PATH_SEGMENT + "/**")
                 .antMatchers(this.adminAPIEndpoint + API.REGISTER_ENDPOINT);
     }
 
-    @RequestMapping("/error")
+    @RequestMapping(CHECK_PATH)
+    public void check() throws IOException {
+    }
+
+    @RequestMapping(ERROR_PATH)
     public void handleError(final HttpServletResponse response) throws IOException {
-        //response.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY);
+        response.getOutputStream().print(response.getStatus());
         response.setHeader(HttpHeaders.LOCATION, this.guiRedirect);
         response.flushBuffer();
     }
 
     @Override
     public String getErrorPath() {
-        return "/error";
+        return ERROR_PATH;
     }
 }

src/main/java/ch/ethz/seb/sebserver/gbl/api/API.java

@@ -185,6 +185,7 @@ public final class API {
     public static final String EXAM_PROCTORING_ROOM_CONNECTIONS_PATH_SEGMENT = "/room-connections";
     public static final String EXAM_PROCTORING_ACTIVATE_TOWNHALL_ROOM = "activate-towhall-room";
     public static final String EXAM_PROCTORING_TOWNHALL_ROOM_DATA = "towhall-room-data";
+    public static final String EXAM_PROCTORING_TOWNHALL_ROOM_AVAILABLE = "towhall-available";
 
     public static final String EXAM_PROCTORING_ATTR_RECEIVE_AUDIO = "receive_audio";
     public static final String EXAM_PROCTORING_ATTR_RECEIVE_VIDEO = "receive_video";

src/main/java/ch/ethz/seb/sebserver/gui/InstitutionalAuthenticationEntryPoint.java

@@ -116,13 +116,9 @@ public final class InstitutionalAuthenticationEntryPoint implements Authenticati
 
         final String institutionalEndpoint = extractInstitutionalEndpoint(request);
 
-        if (StringUtils.isNoneBlank(institutionalEndpoint) && log.isDebugEnabled()) {
+        if (StringUtils.isNotBlank(institutionalEndpoint)) {
+            if (log.isDebugEnabled()) {
                 log.debug("No default gui entrypoint requested: {}", institutionalEndpoint);
-        } else {
-            request.getSession().setAttribute(INST_SUFFIX_ATTRIBUTE, null);
-            request.getSession().removeAttribute(API.PARAM_LOGO_IMAGE);
-            forwardToEntryPoint(request, response, this.guiEntryPoint, false);
-            return;
             }
 
             try {
@@ -163,13 +159,13 @@ public final class InstitutionalAuthenticationEntryPoint implements Authenticati
                 }
             } catch (final Exception e) {
                 log.error("Failed to extract and set institutional endpoint request: ", e);
-
+            }
         }
 
         request.getSession().setAttribute(INST_SUFFIX_ATTRIBUTE, null);
         request.getSession().removeAttribute(API.PARAM_LOGO_IMAGE);
         response.setStatus(HttpStatus.UNAUTHORIZED.value());
-        forwardToEntryPoint(request, response, this.guiEntryPoint, true);
+        forwardToEntryPoint(request, response, this.guiEntryPoint, institutionalEndpoint == null);
 
     }
 
@@ -203,16 +199,25 @@ public final class InstitutionalAuthenticationEntryPoint implements Authenticati
 
     public static String extractInstitutionalEndpoint(final HttpServletRequest request) {
         final String requestURI = request.getRequestURI();
-        if (StringUtils.isBlank(requestURI) || requestURI.equals(Constants.SLASH.toString())) {
+        if (StringUtils.isBlank(requestURI)) {
             return null;
         }
 
+        if (requestURI.equals(Constants.SLASH.toString())) {
+            return StringUtils.EMPTY;
+        }
+
+        try {
             if (log.isDebugEnabled()) {
                 log.debug("Trying to verify institution from requested entrypoint url: {}", requestURI);
             }
 
-        try {
+            final String[] split = StringUtils.split(requestURI, Constants.SLASH);
-            return requestURI.substring(requestURI.lastIndexOf(Constants.SLASH) + 1);
+            if (split.length > 1) {
+                return null;
+            }
+
+            return split[0];
         } catch (final Exception e) {
             log.error("Failed to extract institutional URL suffix: {}", e.getMessage());
             return null;

src/main/java/ch/ethz/seb/sebserver/gui/content/MonitoringRunningExam.java

@@ -17,6 +17,7 @@ import java.util.function.BooleanSupplier;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
+import org.apache.commons.lang3.BooleanUtils;
 import org.eclipse.rap.rwt.RWT;
 import org.eclipse.rap.rwt.client.service.JavaScriptExecutor;
 import org.eclipse.swt.SWT;
@@ -77,7 +78,7 @@ import ch.ethz.seb.sebserver.gui.service.remote.webservice.api.exam.GetProctorin
 import ch.ethz.seb.sebserver.gui.service.remote.webservice.api.session.GetClientConnectionDataList;
 import ch.ethz.seb.sebserver.gui.service.remote.webservice.api.session.GetCollectingRooms;
 import ch.ethz.seb.sebserver.gui.service.remote.webservice.api.session.GetProctorRoomConnection;
-import ch.ethz.seb.sebserver.gui.service.remote.webservice.api.session.GetTownhallRoom;
+import ch.ethz.seb.sebserver.gui.service.remote.webservice.api.session.IsTownhallRoomAvailable;
 import ch.ethz.seb.sebserver.gui.service.remote.webservice.auth.CurrentUser;
 import ch.ethz.seb.sebserver.gui.service.session.ClientConnectionTable;
 import ch.ethz.seb.sebserver.gui.service.session.InstructionProcessor;
@@ -123,6 +124,7 @@ public class MonitoringRunningExam implements TemplateComposer {
 
     private final ServerPushService serverPushService;
     private final PageService pageService;
+    private final RestService restService;
     private final ResourceService resourceService;
     private final AsyncRunner asyncRunner;
     private final InstructionProcessor instructionProcessor;
@@ -147,6 +149,7 @@ public class MonitoringRunningExam implements TemplateComposer {
 
         this.serverPushService = serverPushService;
         this.pageService = pageService;
+        this.restService = pageService.getRestService();
         this.resourceService = pageService.getResourceService();
         this.asyncRunner = asyncRunner;
         this.instructionProcessor = instructionProcessor;
@@ -214,13 +217,14 @@ public class MonitoringRunningExam implements TemplateComposer {
 
         this.serverPushService.runServerPush(
                 new ServerPushContext(
-                        content, Utils.truePredicate(),
+                        content,
+                        Utils.truePredicate(),
                         createServerPushUpdateErrorHandler(this.pageService, pageContext)),
                 this.pollInterval,
                 context -> clientTable.updateValues(),
                 updateTableGUI(clientTable));
 
-        final BooleanSupplier privilege = () -> currentUser.get().hasRole(UserRole.EXAM_SUPPORTER);
+        final BooleanSupplier isExamSupporter = () -> currentUser.get().hasRole(UserRole.EXAM_SUPPORTER);
 
         actionBuilder
 
@@ -242,20 +246,20 @@ public class MonitoringRunningExam implements TemplateComposer {
 
                     return copyOfPageAction;
                 })
-                .publishIf(privilege, false)
+                .publishIf(isExamSupporter, false)
 
                 .newAction(ActionDefinition.MONITOR_EXAM_QUIT_ALL)
                 .withEntityKey(entityKey)
                 .withConfirm(() -> CONFIRM_QUIT_ALL)
                 .withExec(action -> this.quitSEBClients(action, clientTable, true))
                 .noEventPropagation()
-                .publishIf(privilege)
+                .publishIf(isExamSupporter)
 
                 .newAction(ActionDefinition.MONITORING_EXAM_SEARCH_CONNECTIONS)
                 .withEntityKey(entityKey)
                 .withExec(this::openSearchPopup)
                 .noEventPropagation()
-                .publishIf(privilege)
+                .publishIf(isExamSupporter)
 
                 .newAction(ActionDefinition.MONITOR_EXAM_QUIT_SELECTED)
                 .withEntityKey(entityKey)
@@ -265,7 +269,7 @@ public class MonitoringRunningExam implements TemplateComposer {
                         action -> this.quitSEBClients(action, clientTable, false),
                         EMPTY_ACTIVE_SELECTION_TEXT_KEY)
                 .noEventPropagation()
-                .publishIf(privilege, false)
+                .publishIf(isExamSupporter, false)
 
                 .newAction(ActionDefinition.MONITOR_EXAM_DISABLE_SELECTED_CONNECTION)
                 .withEntityKey(entityKey)
@@ -275,31 +279,111 @@ public class MonitoringRunningExam implements TemplateComposer {
                         action -> this.disableSEBClients(action, clientTable, false),
                         EMPTY_SELECTION_TEXT_KEY)
                 .noEventPropagation()
-                .publishIf(privilege, false);
+                .publishIf(isExamSupporter, false);
 
-        if (privilege.getAsBoolean()) {
+        if (isExamSupporter.getAsBoolean()) {
+            addFilterActions(actionBuilder, clientTable, isExamSupporter);
+            addProctoringActions(
+                    currentUser.getProctoringGUIService(),
+                    pageContext,
+                    content,
+                    actionBuilder);
+        }
+    }
 
-            if (clientTable.isStatusHidden(ConnectionStatus.CLOSED)) {
+    private void addProctoringActions(
-                actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_SHOW_CLOSED_CONNECTION)
+            final ProctoringGUIService proctoringGUIService,
-                        .withExec(showStateViewAction(clientTable, ConnectionStatus.CLOSED))
+            final PageContext pageContext,
+            final Composite parent,
+            final PageActionBuilder actionBuilder) {
+
+        final EntityKey entityKey = pageContext.getEntityKey();
+        final ProctoringServiceSettings proctoringSettings = this.restService
+                .getBuilder(GetProctoringSettings.class)
+                .withURIVariable(API.PARAM_MODEL_ID, entityKey.modelId)
+                .call()
+                .getOr(null);
+
+        if (proctoringSettings != null && proctoringSettings.enableProctoring) {
+
+            actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_OPEN_TOWNHALL_PROCTOR_ROOM)
+                    .withEntityKey(entityKey)
+                    .withExec(action -> this.toggleTownhallRoom(proctoringGUIService, action))
+                    .noEventPropagation()
+                    .publish();
+
+            if (isTownhallRoomActive(entityKey.modelId)) {
+                this.pageService.firePageEvent(
+                        new ActionActivationEvent(
+                                true,
+                                new Tuple<>(
+                                        ActionDefinition.MONITOR_EXAM_OPEN_TOWNHALL_PROCTOR_ROOM,
+                                        ActionDefinition.MONITOR_EXAM_CLOSE_TOWNHALL_PROCTOR_ROOM)),
+                        pageContext);
+            }
+
+            final Map<String, Pair<RemoteProctoringRoom, TreeItem>> availableRooms = new HashMap<>();
+            updateRoomActions(
+                    pageContext,
+                    availableRooms,
+                    actionBuilder,
+                    proctoringSettings,
+                    proctoringGUIService);
+            this.serverPushService.runServerPush(
+                    new ServerPushContext(
+                            parent,
+                            Utils.truePredicate(),
+                            createServerPushUpdateErrorHandler(this.pageService, pageContext)),
+                    this.proctoringRoomUpdateInterval,
+                    context -> updateRoomActions(
+                            pageContext,
+                            availableRooms,
+                            actionBuilder,
+                            proctoringSettings,
+                            proctoringGUIService));
+        }
+    }
+
+    private void addFilterActions(
+            final PageActionBuilder actionBuilder,
+            final ClientConnectionTable clientTable,
+            final BooleanSupplier isExamSupporter) {
+
+        addClosedFilterAction(actionBuilder, clientTable);
+        addRequestedFilterAction(actionBuilder, clientTable);
+        addDisabledFilterAction(actionBuilder, clientTable);
+    }
+
+    private void addDisabledFilterAction(
+            final PageActionBuilder actionBuilder,
+            final ClientConnectionTable clientTable) {
+
+        if (clientTable.isStatusHidden(ConnectionStatus.DISABLED)) {
+            actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_SHOW_DISABLED_CONNECTION)
+                    .withExec(showStateViewAction(clientTable, ConnectionStatus.DISABLED))
                     .noEventPropagation()
                     .withSwitchAction(
-                                actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_HIDE_CLOSED_CONNECTION)
+                            actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_HIDE_DISABLED_CONNECTION)
-                                        .withExec(hideStateViewAction(clientTable, ConnectionStatus.CLOSED))
+                                    .withExec(hideStateViewAction(clientTable, ConnectionStatus.DISABLED))
                                     .noEventPropagation()
                                     .create())
                     .publish();
         } else {
-                actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_HIDE_CLOSED_CONNECTION)
+            actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_HIDE_DISABLED_CONNECTION)
-                        .withExec(hideStateViewAction(clientTable, ConnectionStatus.CLOSED))
+                    .withExec(hideStateViewAction(clientTable, ConnectionStatus.DISABLED))
                     .noEventPropagation()
                     .withSwitchAction(
-                                actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_SHOW_CLOSED_CONNECTION)
+                            actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_SHOW_DISABLED_CONNECTION)
-                                        .withExec(showStateViewAction(clientTable, ConnectionStatus.CLOSED))
+                                    .withExec(showStateViewAction(clientTable, ConnectionStatus.DISABLED))
                                     .noEventPropagation()
                                     .create())
                     .publish();
         }
+    }
+
+    private void addRequestedFilterAction(
+            final PageActionBuilder actionBuilder,
+            final ClientConnectionTable clientTable) {
 
         if (clientTable.isStatusHidden(ConnectionStatus.CONNECTION_REQUESTED)) {
             actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_SHOW_REQUESTED_CONNECTION)
@@ -324,85 +408,42 @@ public class MonitoringRunningExam implements TemplateComposer {
                                     .create())
                     .publish();
         }
+    }
 
-            if (clientTable.isStatusHidden(ConnectionStatus.DISABLED)) {
+    private void addClosedFilterAction(
-                actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_SHOW_DISABLED_CONNECTION)
+            final PageActionBuilder actionBuilder,
-                        .withExec(showStateViewAction(clientTable, ConnectionStatus.DISABLED))
+            final ClientConnectionTable clientTable) {
+
+        if (clientTable.isStatusHidden(ConnectionStatus.CLOSED)) {
+            actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_SHOW_CLOSED_CONNECTION)
+                    .withExec(showStateViewAction(clientTable, ConnectionStatus.CLOSED))
                     .noEventPropagation()
                     .withSwitchAction(
-                                actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_HIDE_DISABLED_CONNECTION)
+                            actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_HIDE_CLOSED_CONNECTION)
-                                        .withExec(hideStateViewAction(clientTable, ConnectionStatus.DISABLED))
+                                    .withExec(hideStateViewAction(clientTable, ConnectionStatus.CLOSED))
                                     .noEventPropagation()
                                     .create())
                     .publish();
         } else {
-                actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_HIDE_DISABLED_CONNECTION)
+            actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_HIDE_CLOSED_CONNECTION)
-                        .withExec(hideStateViewAction(clientTable, ConnectionStatus.DISABLED))
+                    .withExec(hideStateViewAction(clientTable, ConnectionStatus.CLOSED))
                     .noEventPropagation()
                     .withSwitchAction(
-                                actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_SHOW_DISABLED_CONNECTION)
+                            actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_SHOW_CLOSED_CONNECTION)
-                                        .withExec(showStateViewAction(clientTable, ConnectionStatus.DISABLED))
+                                    .withExec(showStateViewAction(clientTable, ConnectionStatus.CLOSED))
                                     .noEventPropagation()
                                     .create())
                     .publish();
         }
-
-        }
-
-        final ProctoringServiceSettings proctoringSettings = restService
-                .getBuilder(GetProctoringSettings.class)
-                .withURIVariable(API.PARAM_MODEL_ID, entityKey.modelId)
-                .call()
-                .getOr(null);
-
-        if (proctoringSettings != null && proctoringSettings.enableProctoring) {
-
-            actionBuilder.newAction(ActionDefinition.MONITOR_EXAM_OPEN_TOWNHALL_PROCTOR_ROOM)
-                    .withEntityKey(entityKey)
-                    .withExec(this::toggleTownhallRoom)
-                    .noEventPropagation()
-                    .publish();
-
-            if (isTownhallRoomActive(entityKey.modelId)) {
-                this.pageService.firePageEvent(
-                        new ActionActivationEvent(
-                                true,
-                                new Tuple<>(
-                                        ActionDefinition.MONITOR_EXAM_OPEN_TOWNHALL_PROCTOR_ROOM,
-                                        ActionDefinition.MONITOR_EXAM_CLOSE_TOWNHALL_PROCTOR_ROOM)),
-                        pageContext);
-            }
-
-            final Map<String, Pair<RemoteProctoringRoom, TreeItem>> availableRooms = new HashMap<>();
-            updateRoomActions(
-                    entityKey,
-                    pageContext,
-                    availableRooms,
-                    actionBuilder,
-                    proctoringSettings);
-            this.serverPushService.runServerPush(
-                    new ServerPushContext(
-                            content,
-                            Utils.truePredicate(),
-                            createServerPushUpdateErrorHandler(this.pageService, pageContext)),
-                    this.proctoringRoomUpdateInterval,
-                    context -> updateRoomActions(
-                            entityKey,
-                            pageContext,
-                            availableRooms,
-                            actionBuilder,
-                            proctoringSettings));
-        }
     }
 
     private boolean isTownhallRoomActive(final String examModelId) {
-        final RemoteProctoringRoom townhall = this.pageService.getRestService()
+        return !BooleanUtils.toBoolean(this.pageService
-                .getBuilder(GetTownhallRoom.class)
+                .getRestService()
+                .getBuilder(IsTownhallRoomAvailable.class)
                 .withURIVariable(API.PARAM_MODEL_ID, examModelId)
                 .call()
-                .getOr(null);
+                .getOr(Constants.FALSE_STRING));
-
-        return townhall != null && townhall.id != null;
     }
 
     private PageAction openSearchPopup(final PageAction action) {
@@ -410,9 +451,12 @@ public class MonitoringRunningExam implements TemplateComposer {
         return action;
     }
 
-    private PageAction toggleTownhallRoom(final PageAction action) {
+    private PageAction toggleTownhallRoom(
+            final ProctoringGUIService proctoringGUIService,
+            final PageAction action) {
+
         if (isTownhallRoomActive(action.getEntityKey().modelId)) {
-            closeTownhallRoom(action);
+            closeTownhallRoom(proctoringGUIService, action);
             this.pageService.firePageEvent(
                     new ActionActivationEvent(
                             true,
@@ -422,7 +466,7 @@ public class MonitoringRunningExam implements TemplateComposer {
                     action.pageContext());
             return action;
         } else {
-            openTownhallRoom(action);
+            openTownhallRoom(proctoringGUIService, action);
             this.pageService.firePageEvent(
                     new ActionActivationEvent(
                             true,
@@ -434,14 +478,13 @@ public class MonitoringRunningExam implements TemplateComposer {
         }
     }
 
-    private PageAction openTownhallRoom(final PageAction action) {
+    private PageAction openTownhallRoom(
+            final ProctoringGUIService proctoringGUIService,
+            final PageAction action) {
+
         try {
             final EntityKey examId = action.getEntityKey();
 
-            final ProctoringGUIService proctoringGUIService = this.pageService
-                    .getCurrentUser()
-                    .getProctoringGUIService();
-
             final String windowName = getTownhallWindowName(examId.modelId);
             if (!proctoringGUIService.hasWindow(windowName)) {
                 final ProctoringRoomConnection proctoringConnectionData = proctoringGUIService
@@ -475,11 +518,10 @@ public class MonitoringRunningExam implements TemplateComposer {
         return action;
     }
 
-    private String getTownhallWindowName(final String examId) {
+    private PageAction closeTownhallRoom(
-        return examId + "_townhall";
+            final ProctoringGUIService proctoringGUIService,
-    }
+            final PageAction action) {
 
-    private PageAction closeTownhallRoom(final PageAction action) {
         final String examId = action.getEntityKey().modelId;
         try {
 
@@ -494,8 +536,15 @@ public class MonitoringRunningExam implements TemplateComposer {
         return action;
     }
 
-    private void updateTownhallButton(final EntityKey entityKey, final PageContext pageContext) {
+    private void updateTownhallButton(
+            final ProctoringGUIService proctoringGUIService,
+            final PageContext pageContext) {
+        final EntityKey entityKey = pageContext.getEntityKey();
+
         if (isTownhallRoomActive(entityKey.modelId)) {
+            final boolean townhallRoomFromThisUser = proctoringGUIService
+                    .isTownhallOpenForUser(entityKey.modelId);
+            if (townhallRoomFromThisUser) {
                 this.pageService.firePageEvent(
                         new ActionActivationEvent(
                                 true,
@@ -503,25 +552,36 @@ public class MonitoringRunningExam implements TemplateComposer {
                                         ActionDefinition.MONITOR_EXAM_OPEN_TOWNHALL_PROCTOR_ROOM,
                                         ActionDefinition.MONITOR_EXAM_CLOSE_TOWNHALL_PROCTOR_ROOM)),
                         pageContext);
+            } else {
+                this.pageService.firePageEvent(
+                        new ActionActivationEvent(
+                                false,
+                                ActionDefinition.MONITOR_EXAM_OPEN_TOWNHALL_PROCTOR_ROOM,
+                                ActionDefinition.MONITOR_EXAM_CLOSE_TOWNHALL_PROCTOR_ROOM),
+                        pageContext);
+            }
         } else {
             this.pageService.firePageEvent(
                     new ActionActivationEvent(
                             true,
                             new Tuple<>(
                                     ActionDefinition.MONITOR_EXAM_OPEN_TOWNHALL_PROCTOR_ROOM,
-                                    ActionDefinition.MONITOR_EXAM_OPEN_TOWNHALL_PROCTOR_ROOM)),
+                                    ActionDefinition.MONITOR_EXAM_OPEN_TOWNHALL_PROCTOR_ROOM),
+                            ActionDefinition.MONITOR_EXAM_OPEN_TOWNHALL_PROCTOR_ROOM,
+                            ActionDefinition.MONITOR_EXAM_CLOSE_TOWNHALL_PROCTOR_ROOM),
                     pageContext);
         }
     }
 
     private void updateRoomActions(
-            final EntityKey entityKey,
             final PageContext pageContext,
             final Map<String, Pair<RemoteProctoringRoom, TreeItem>> rooms,
             final PageActionBuilder actionBuilder,
-            final ProctoringServiceSettings proctoringSettings) {
+            final ProctoringServiceSettings proctoringSettings,
+            final ProctoringGUIService proctoringGUIService) {
 
-        updateTownhallButton(entityKey, pageContext);
+        final EntityKey entityKey = pageContext.getEntityKey();
+        updateTownhallButton(proctoringGUIService, pageContext);
         final I18nSupport i18nSupport = this.pageService.getI18nSupport();
         this.pageService
                 .getRestService()
@@ -564,7 +624,7 @@ public class MonitoringRunningExam implements TemplateComposer {
                         this.pageService.publishAction(
                                 action,
                                 _treeItem -> rooms.put(room.name, new Pair<>(room, _treeItem)));
-                        addRoomConnectionsPopupListener(entityKey, pageContext, rooms);
+                        addRoomConnectionsPopupListener(pageContext, rooms);
                         processProctorRoomActionActivation(rooms.get(room.name).b, room, pageContext);
                     }
                 });
@@ -589,11 +649,11 @@ public class MonitoringRunningExam implements TemplateComposer {
     }
 
     private void addRoomConnectionsPopupListener(
-            final EntityKey entityKey,
             final PageContext pageContext,
             final Map<String, Pair<RemoteProctoringRoom, TreeItem>> rooms) {
 
         if (!rooms.isEmpty()) {
+            final EntityKey entityKey = pageContext.getEntityKey();
             final TreeItem treeItem = rooms.values().iterator().next().b;
             final Tree tree = treeItem.getParent();
             if (tree.getData(SHOW_CONNECTION_ACTION_APPLIED) == null) {
@@ -775,4 +835,8 @@ public class MonitoringRunningExam implements TemplateComposer {
         };
     }
 
+    private String getTownhallWindowName(final String examId) {
+        return examId + "_townhall";
+    }
+
 }

src/main/java/ch/ethz/seb/sebserver/gui/service/page/impl/JitsiMeetProctoringView.java

@@ -84,17 +84,18 @@ public class JitsiMeetProctoringView implements RemoteProctoringView {
     public void compose(final PageContext pageContext) {
 
         final ProctoringWindowData proctoringWindowData = ProctoringGUIService.getCurrentProctoringWindowData();
-
         final Composite parent = pageContext.getParent();
-
         final Composite content = new Composite(parent, SWT.NONE | SWT.NO_SCROLL);
         final GridLayout gridLayout = new GridLayout();
+        final ProctoringGUIService proctoringGUIService = this.pageService
+                .getCurrentUser()
+                .getProctoringGUIService();
 
         content.setLayout(gridLayout);
         final GridData headerCell = new GridData(SWT.FILL, SWT.FILL, true, true);
         content.setLayoutData(headerCell);
 
-        parent.addListener(SWT.Dispose, event -> closeRoom(proctoringWindowData));
+        parent.addListener(SWT.Dispose, event -> closeRoom(proctoringGUIService, proctoringWindowData));
 
         final String url = this.guiServiceInfo
                 .getExternalServerURIBuilder()
@@ -124,7 +125,7 @@ public class JitsiMeetProctoringView implements RemoteProctoringView {
 
         final Button closeAction = widgetFactory.buttonLocalized(footer, CLOSE_WINDOW_TEXT_KEY);
         closeAction.setLayoutData(new RowData(150, 30));
-        closeAction.addListener(SWT.Selection, event -> closeRoom(proctoringWindowData));
+        closeAction.addListener(SWT.Selection, event -> closeRoom(proctoringGUIService, proctoringWindowData));
 
         final BroadcastActionState broadcastActionState = new BroadcastActionState();
 
@@ -232,11 +233,15 @@ public class JitsiMeetProctoringView implements RemoteProctoringView {
         sendReconfigurationAttributes(examId, roomName, state);
     }
 
-    private void closeRoom(final ProctoringWindowData proctoringWindowData) {
+    private void closeRoom(
-        this.pageService
+            final ProctoringGUIService proctoringGUIService,
-                .getCurrentUser()
+            final ProctoringWindowData proctoringWindowData) {
-                .getProctoringGUIService()
+
-                .closeRoomWindow(proctoringWindowData.windowName);
+        try {
+            proctoringGUIService.closeRoomWindow(proctoringWindowData.connectionData.roomName);
+        } catch (final Exception e) {
+            log.error("Failed to close proctoring window properly: ", e);
+        }
     }
 
     static final class BroadcastActionState {

src/main/java/ch/ethz/seb/sebserver/gui/service/remote/webservice/api/session/IsTownhallRoomAvailable.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2021 ETH Zürich, Educational Development and Technology (LET)
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+package ch.ethz.seb.sebserver.gui.service.remote.webservice.api.session;
+
+import org.springframework.context.annotation.Lazy;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.MediaType;
+import org.springframework.stereotype.Component;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import ch.ethz.seb.sebserver.gbl.api.API;
+import ch.ethz.seb.sebserver.gbl.api.EntityType;
+import ch.ethz.seb.sebserver.gbl.profile.GuiProfile;
+import ch.ethz.seb.sebserver.gui.service.remote.webservice.api.RestCall;
+
+@Lazy
+@Component
+@GuiProfile
+public class IsTownhallRoomAvailable extends RestCall<String> {
+
+    public IsTownhallRoomAvailable() {
+        super(new TypeKey<>(
+                CallType.GET_SINGLE,
+                EntityType.REMOTE_PROCTORING_ROOM,
+                new TypeReference<String>() {
+                }),
+                HttpMethod.GET,
+                MediaType.APPLICATION_FORM_URLENCODED,
+                API.EXAM_PROCTORING_ENDPOINT
+                        + API.MODEL_ID_VAR_PATH_SEGMENT
+                        + API.EXAM_PROCTORING_TOWNHALL_ROOM_AVAILABLE);
+    }
+
+}

src/main/java/ch/ethz/seb/sebserver/gui/service/session/proctoring/ProctoringGUIService.java

@@ -50,6 +50,13 @@ public class ProctoringGUIService {
         this.openWindows.put(windowName, new RoomData(roomName, examId));
     }
 
+    public boolean isTownhallOpenForUser(final String examId) {
+        return this.openWindows.values().stream()
+                .filter(room -> room.isTownhall && room.examId.equals(examId))
+                .findFirst()
+                .isPresent();
+    }
+
     public static ProctoringWindowData getCurrentProctoringWindowData() {
         return (ProctoringWindowData) RWT.getUISession()
                 .getHttpSession()
@@ -105,7 +112,7 @@ public class ProctoringGUIService {
                 .withFormParam(ProctoringRoomConnection.ATTR_SUBJECT, subject)
                 .call()
                 .map(connection -> {
-                    this.openWindows.put(windowName, new RoomData(connection.roomName, examId));
+                    this.openWindows.put(windowName, new RoomData(connection.roomName, examId, true));
                     return connection;
                 });
     }
@@ -152,10 +159,16 @@ public class ProctoringGUIService {
     private static final class RoomData {
         final String roomName;
         final String examId;
+        final boolean isTownhall;
 
         public RoomData(final String roomName, final String examId) {
+            this(roomName, examId, false);
+        }
+
+        public RoomData(final String roomName, final String examId, final boolean townhall) {
             this.roomName = roomName;
             this.examId = examId;
+            this.isTownhall = townhall;
         }
     }
 

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/RemoteProctoringRoomDAO.java

@@ -59,6 +59,8 @@ public interface RemoteProctoringRoomDAO {
      * @return Result refer to the created room record or to an error when happened */
     Result<RemoteProctoringRoom> createTownhallRoom(Long examId, NewRoom room);
 
+    boolean isTownhallRoomActive(Long examId);
+
     /** Get the town hall room record for a given exam if existing.
      *
      * @param examId the exam identifier

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/dao/impl/RemoteProctoringRoomDAOImpl.java

@@ -20,6 +20,8 @@ import java.util.stream.Collectors;
 
 import org.apache.commons.lang3.BooleanUtils;
 import org.apache.commons.lang3.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.context.annotation.Lazy;
 import org.springframework.stereotype.Component;
 import org.springframework.transaction.annotation.Transactional;
@@ -42,6 +44,8 @@ import ch.ethz.seb.sebserver.webservice.servicelayer.session.impl.proctoring.New
 @WebServiceProfile
 public class RemoteProctoringRoomDAOImpl implements RemoteProctoringRoomDAO {
 
+    private static final Logger log = LoggerFactory.getLogger(RemoteProctoringRoomDAOImpl.class);
+
     private static final Object RESERVE_ROOM_LOCK = new Object();
 
     private final RemoteProctoringRoomRecordMapper remoteProctoringRoomRecordMapper;
@@ -129,15 +133,10 @@ public class RemoteProctoringRoomDAOImpl implements RemoteProctoringRoomDAO {
             final NewRoom room) {
 
         return Result.tryCatch(() -> {
-            // check first if town-hall room is not already active
-            final long active = this.remoteProctoringRoomRecordMapper.countByExample()
-                    .where(RemoteProctoringRoomRecordDynamicSqlSupport.examId, isEqualTo(examId))
-                    .and(RemoteProctoringRoomRecordDynamicSqlSupport.townhallRoom, isNotEqualTo(0))
-                    .build()
-                    .execute();
 
-            if (active > 0) {
+            // Check first if town-hall room is not already active
-                throw new IllegalStateException("Townhall, for exam: " + examId + " already existis");
+            if (isTownhallRoomActive(examId)) {
+                throw new IllegalStateException("Townhall, for exam: " + examId + " already exists");
             }
 
             final RemoteProctoringRoomRecord townhallRoomRecord = new RemoteProctoringRoomRecord(
@@ -159,6 +158,24 @@ public class RemoteProctoringRoomDAOImpl implements RemoteProctoringRoomDAO {
                 .onError(TransactionHandler::rollback);
     }
 
+    @Override
+    @Transactional(readOnly = true)
+    public boolean isTownhallRoomActive(final Long examId) {
+        try {
+            final long active = this.remoteProctoringRoomRecordMapper.countByExample()
+                    .where(RemoteProctoringRoomRecordDynamicSqlSupport.examId, isEqualTo(examId))
+                    .and(RemoteProctoringRoomRecordDynamicSqlSupport.townhallRoom, isNotEqualTo(0))
+                    .build()
+                    .execute();
+            return (active > 0);
+        } catch (final Exception e) {
+            log.error(
+                    "Failed to verify town-hall room activity for exam: {}. Mark it as active to avoid double openings",
+                    examId, e);
+            return true;
+        }
+    }
+
     @Override
     @Transactional
     public Result<EntityKey> deleteTownhallRoom(final Long examId) {

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/ExamProctoringRoomService.java

@@ -58,6 +58,8 @@ public interface ExamProctoringRoomService {
      * @return Result refer to the given exam or to an error when happened */
     Result<Exam> disposeRoomsForExam(Exam exam);
 
+    boolean isTownhallRoomActive(final Long examId);
+
     /** This creates a town-hall room for a specific exam. The exam must be active and running
      * and there must be no other town-hall room already be active. An unique room name will be
      * created and returned.

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/session/impl/proctoring/ExamProctoringRoomServiceImpl.java

@@ -318,6 +318,11 @@ public class ExamProctoringRoomServiceImpl implements ExamProctoringRoomService
         }
     }
 
+    @Override
+    public boolean isTownhallRoomActive(final Long examId) {
+        return this.remoteProctoringRoomDAO.isTownhallRoomActive(examId);
+    }
+
     private void closeTownhall(
             final Long examId,
             final ProctoringServiceSettings proctoringSettings,
@@ -593,4 +598,5 @@ public class ExamProctoringRoomServiceImpl implements ExamProctoringRoomService
                         true)
                 .onError(error -> log.error("Failed to send join instruction: {}", connectionToken, error));
     }
+
 }

src/main/java/ch/ethz/seb/sebserver/webservice/weblayer/api/ExamAPI_V1_Controller.java

@@ -21,6 +21,7 @@ import javax.servlet.ServletOutputStream;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Qualifier;
@@ -35,6 +36,7 @@ import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.ResponseStatus;
 import org.springframework.web.bind.annotation.RestController;
 
+import ch.ethz.seb.sebserver.gbl.Constants;
 import ch.ethz.seb.sebserver.gbl.api.API;
 import ch.ethz.seb.sebserver.gbl.api.APIMessage;
 import ch.ethz.seb.sebserver.gbl.api.JSONMapper;
@@ -101,7 +103,7 @@ public class ExamAPI_V1_Controller {
 
                     final POSTMapper mapper = new POSTMapper(formParams, request.getQueryString());
 
-                    final String remoteAddr = request.getRemoteAddr();
+                    final String remoteAddr = this.getClientAddress(request);
                     final Long institutionId = (instIdRequestParam != null)
                             ? instIdRequestParam
                             : mapper.getLong(API.PARAM_INSTITUTION_ID);
@@ -163,7 +165,7 @@ public class ExamAPI_V1_Controller {
         return CompletableFuture.runAsync(
                 () -> {
 
-                    final String remoteAddr = request.getRemoteAddr();
+                    final String remoteAddr = this.getClientAddress(request);
                     final Long institutionId = getInstitutionId(principal);
 
                     this.sebClientConnectionService.updateClientConnection(
@@ -193,7 +195,7 @@ public class ExamAPI_V1_Controller {
         return CompletableFuture.runAsync(
                 () -> {
 
-                    final String remoteAddr = request.getRemoteAddr();
+                    final String remoteAddr = this.getClientAddress(request);
                     final Long institutionId = getInstitutionId(principal);
 
                     this.sebClientConnectionService.establishClientConnection(
@@ -220,7 +222,7 @@ public class ExamAPI_V1_Controller {
         return CompletableFuture.runAsync(
                 () -> {
 
-                    final String remoteAddr = request.getRemoteAddr();
+                    final String remoteAddr = this.getClientAddress(request);
                     final Long institutionId = getInstitutionId(principal);
 
                     if (log.isDebugEnabled()) {
@@ -406,4 +408,23 @@ public class ExamAPI_V1_Controller {
         }
     }
 
+    private String getClientAddress(final HttpServletRequest request) {
+        try {
+            final String ipAddress = request.getHeader("X-FORWARDED-FOR");
+
+            if (ipAddress == null) {
+                return request.getRemoteAddr();
+            }
+
+            if (ipAddress.contains(",")) {
+                return StringUtils.split(ipAddress, Constants.COMMA)[0];
+            }
+
+            return ipAddress;
+        } catch (final Exception e) {
+            log.warn("Failed to verify client IP address: {}", e.getMessage());
+            return request.getHeader("X-FORWARDED-FOR");
+        }
+    }
+
 }

src/main/java/ch/ethz/seb/sebserver/webservice/weblayer/api/ExamProctoringController.java

@@ -234,6 +234,22 @@ public class ExamProctoringController {
                 .onError(error -> log.error("Failed to close remote proctoring break out room {}", roomName, error));
     }
 
+    @RequestMapping(
+            path = API.MODEL_ID_VAR_PATH_SEGMENT
+                    + API.EXAM_PROCTORING_TOWNHALL_ROOM_AVAILABLE,
+            method = RequestMethod.GET,
+            produces = MediaType.APPLICATION_JSON_VALUE)
+    public String isTownhallRoomAvialbale(
+            @RequestParam(
+                    name = API.PARAM_INSTITUTION_ID,
+                    required = true,
+                    defaultValue = UserService.USERS_INSTITUTION_AS_DEFAULT) final Long institutionId,
+            @PathVariable(name = API.PARAM_MODEL_ID) final Long examId) {
+
+        checkExamReadAccess(institutionId);
+        return String.valueOf(!this.examProcotringRoomService.isTownhallRoomActive(examId));
+    }
+
     @RequestMapping(
             path = API.MODEL_ID_VAR_PATH_SEGMENT
                     + API.EXAM_PROCTORING_TOWNHALL_ROOM_DATA,
@@ -246,7 +262,7 @@ public class ExamProctoringController {
                     defaultValue = UserService.USERS_INSTITUTION_AS_DEFAULT) final Long institutionId,
             @PathVariable(name = API.PARAM_MODEL_ID) final Long examId) {
 
-        checkAccess(institutionId, examId);
+        checkExamReadAccess(institutionId);
         return this.examProcotringRoomService
                 .getTownhallRoomData(examId)
                 .getOrElse(() -> RemoteProctoringRoom.NULL_ROOM);
@@ -273,6 +289,13 @@ public class ExamProctoringController {
                 .getOrThrow();
     }
 
+    private void checkExamReadAccess(final Long institutionId) {
+        this.authorization.check(
+                PrivilegeType.READ,
+                EntityType.EXAM,
+                institutionId);
+    }
+
     private void checkAccess(final Long institutionId, final Long examId) {
         this.authorization.check(
                 PrivilegeType.READ,