SEBSERV-62 testing and fixes

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

@@ -152,7 +152,7 @@ public class APIMessage implements Serializable {
 
     /** Use this as a conversion from a given FieldError of Spring to a APIMessage
      * of type field validation.
-     * 
+     *
      * @param error FieldError instance
      * @return converted APIMessage of type field validation */
     public static final APIMessage fieldValidationError(final FieldError error) {

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/client/ClientCredentialService.java

@@ -55,12 +55,6 @@ public interface ClientCredentialService {
         return encryptClientCredentials(clientIdPlaintext, secretPlaintext, null);
     }
 
-//    /** Use this to get a decrypted plain text clientId form given ClientCredentials
-//     *
-//     * @param credentials ClientCredentials containing the clientId to decrypt
-//     * @return decrypted plain text clientId */
-//    CharSequence getPlainClientId(ClientCredentials credentials);
-
     /** Use this to get a decrypted plain text secret form given ClientCredentials
      *
      * @param credentials ClientCredentials containing the secret to decrypt

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/client/ClientCredentialServiceImpl.java

@@ -61,7 +61,7 @@ public class ClientCredentialServiceImpl implements ClientCredentialService {
             final CharSequence accessTokenPlaintext) {
 
         final CharSequence secret = this.environment
-                .getRequiredProperty(SEBSERVER_WEBSERVICE_INTERNAL_SECRET_KEY);
+                .getProperty(SEBSERVER_WEBSERVICE_INTERNAL_SECRET_KEY);
 
         return new ClientCredentials(
                 clientIdPlaintext,
@@ -73,11 +73,6 @@ public class ClientCredentialServiceImpl implements ClientCredentialService {
                         : null);
     }
 
-//    @Override
-//    public CharSequence getPlainClientId(final ClientCredentials credentials) {
-//        return credentials.clientId;
-//    }
-
     @Override
     public CharSequence getPlainClientSecret(final ClientCredentials credentials) {
         if (credentials == null || !credentials.hasSecret()) {
@@ -85,7 +80,7 @@ public class ClientCredentialServiceImpl implements ClientCredentialService {
         }
 
         final CharSequence secret = this.environment
-                .getRequiredProperty(SEBSERVER_WEBSERVICE_INTERNAL_SECRET_KEY);
+                .getProperty(SEBSERVER_WEBSERVICE_INTERNAL_SECRET_KEY);
         return this.decrypt(credentials.secret, secret);
     }
 
@@ -96,7 +91,7 @@ public class ClientCredentialServiceImpl implements ClientCredentialService {
         }
 
         final CharSequence secret = this.environment
-                .getRequiredProperty(SEBSERVER_WEBSERVICE_INTERNAL_SECRET_KEY);
+                .getProperty(SEBSERVER_WEBSERVICE_INTERNAL_SECRET_KEY);
 
         return this.decrypt(credentials.accessToken, secret);
     }
@@ -105,7 +100,7 @@ public class ClientCredentialServiceImpl implements ClientCredentialService {
     public CharSequence encrypt(final CharSequence text) {
 
         final CharSequence secret = this.environment
-                .getRequiredProperty(SEBSERVER_WEBSERVICE_INTERNAL_SECRET_KEY);
+                .getProperty(SEBSERVER_WEBSERVICE_INTERNAL_SECRET_KEY);
 
         return encrypt(text, secret);
     }
@@ -114,7 +109,7 @@ public class ClientCredentialServiceImpl implements ClientCredentialService {
     public CharSequence decrypt(final CharSequence text) {
 
         final CharSequence secret = this.environment
-                .getRequiredProperty(SEBSERVER_WEBSERVICE_INTERNAL_SECRET_KEY);
+                .getProperty(SEBSERVER_WEBSERVICE_INTERNAL_SECRET_KEY);
 
         return decrypt(text, secret);
     }
@@ -124,6 +119,11 @@ public class ClientCredentialServiceImpl implements ClientCredentialService {
             throw new IllegalArgumentException("Text has null reference");
         }
 
+        if (secret == null) {
+            log.warn("No internal secret supplied: skip encryption");
+            return text;
+        }
+
         try {
 
             final CharSequence salt = KeyGenerators.string().generateKey();
@@ -145,6 +145,11 @@ public class ClientCredentialServiceImpl implements ClientCredentialService {
             throw new IllegalArgumentException("Cipher has null reference");
         }
 
+        if (secret == null) {
+            log.warn("No internal secret supplied: skip decryption");
+            return cipher;
+        }
+
         try {
 
             final int length = cipher.length();

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

@@ -8,13 +8,25 @@
 
 package ch.ethz.seb.sebserver.webservice.servicelayer.dao;
 
+import java.util.Collection;
+
 import ch.ethz.seb.sebserver.gbl.model.session.ClientConnection;
 import ch.ethz.seb.sebserver.gbl.util.Result;
 
 public interface ClientConnectionDAO extends EntityDAO<ClientConnection, ClientConnection> {
 
-    Result<ClientConnection> byConnectionToken(Long institutionId, String connectionToken);
+    /** Get a list of all connection tokens of all connections (no matter what state)
+     * of an exam.
+     *
+     * @param examId The exam identifier
+     * @return list of all connection tokens of all connections (no matter what state)
+     *         of an exam */
+    Result<Collection<String>> getConnectionTokens(Long examId);
 
+    /** Get a ClientConnection for a specified token.
+     *
+     * @param connectionToken the connection token
+     * @return Result refer to ClientConnection or refer to a error if happened */
     Result<ClientConnection> byConnectionToken(String connectionToken);
 
 }

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

@@ -16,8 +16,21 @@ public interface ExamConfigurationMapDAO extends
         EntityDAO<ExamConfigurationMap, ExamConfigurationMap>,
         BulkActionSupportDAO<ExamConfigurationMap> {
 
+    /** Get the ConfigurationNode identifier of the default Exam Configuration of
+     * the Exam with specified identifier.
+     *
+     * @param examId The Exam identifier
+     * @return ConfigurationNode identifier of the default Exam Configuration of
+     *         the Exam with specified identifier */
     public Result<Long> getDefaultConfigurationForExam(Long examId);
 
+    /** Get the ConfigurationNode identifier of the Exam Configuration of
+     * the Exam for a specified user identifier.
+     *
+     * @param examId The Exam identifier
+     * @param userId the user identifier
+     * @return ConfigurationNode identifier of the Exam Configuration of
+     *         the Exam for a specified user identifier */
     public Result<Long> getUserConfigurationIdForExam(final Long examId, final String userId);
 
 }

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

@@ -110,6 +110,24 @@ public class ClientConnectionDAOImpl implements ClientConnectionDAO {
         });
     }
 
+    @Override
+    @Transactional(readOnly = true)
+    public Result<Collection<String>> getConnectionTokens(final Long examId) {
+        return Result.tryCatch(() -> {
+            return this.clientConnectionRecordMapper
+                    .selectByExample()
+                    .where(
+                            ClientConnectionRecordDynamicSqlSupport.examId,
+                            SqlBuilder.isEqualTo(examId))
+                    .build()
+                    .execute()
+                    .stream()
+                    .map(ClientConnectionRecord::getConnectionToken)
+                    .filter(StringUtils::isNotBlank)
+                    .collect(Collectors.toList());
+        });
+    }
+
     @Override
     @Transactional
     public Result<ClientConnection> createNew(final ClientConnection data) {
@@ -140,10 +158,10 @@ public class ClientConnectionDAOImpl implements ClientConnectionDAO {
             final ClientConnectionRecord updateRecord = new ClientConnectionRecord(
                     data.id,
                     null,
-                    null,
+                    data.examId,
                     data.status != null ? data.status.name() : null,
-                    data.connectionToken,
                     null,
+                    data.userSessionId,
                     data.clientAddress,
                     data.virtualClientAddress);
 
@@ -183,37 +201,6 @@ public class ClientConnectionDAOImpl implements ClientConnectionDAO {
         });
     }
 
-    @Override
-    @Transactional(readOnly = true)
-    public Result<ClientConnection> byConnectionToken(
-            final Long institutionId,
-            final String connectionToken) {
-
-        return Result.tryCatch(() -> {
-            final List<ClientConnectionRecord> list = this.clientConnectionRecordMapper
-                    .selectByExample()
-                    .where(
-                            ClientConnectionRecordDynamicSqlSupport.institutionId,
-                            SqlBuilder.isEqualTo(institutionId))
-                    .and(
-                            ClientConnectionRecordDynamicSqlSupport.connectionToken,
-                            SqlBuilder.isEqualTo(connectionToken))
-                    .build()
-                    .execute();
-
-            if (list.isEmpty()) {
-                throw new ResourceNotFoundException(EntityType.CLIENT_CONNECTION, "connectionToken");
-            }
-
-            if (list.size() > 1) {
-                throw new IllegalStateException("Only one ClientConnection expected but there are: " + list.size());
-            }
-
-            return list.get(0);
-        })
-                .flatMap(ClientConnectionDAOImpl::toDomainModel);
-    }
-
     @Override
     public Result<ClientConnection> byConnectionToken(final String connectionToken) {
         return Result.tryCatch(() -> {

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

@@ -118,7 +118,7 @@ public class ClientEventDAOImpl implements ClientEventDAO {
                     (data.numValue != null) ? new BigDecimal(data.numValue) : null,
                     data.text);
 
-            this.clientEventRecordMapper.insert(newRecord);
+            this.clientEventRecordMapper.insertSelective(newRecord);
             return newRecord;
         })
                 .flatMap(ClientEventDAOImpl::toDomainModel)

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

@@ -130,7 +130,7 @@ public class ExamConfigurationMapDAOImpl implements ExamConfigurationMapDAO {
     @Transactional(readOnly = true)
     public Result<Long> getDefaultConfigurationForExam(final Long examId) {
         return Result.tryCatch(() -> this.examConfigurationMapRecordMapper
-                .selectIdsByExample()
+                .selectByExample()
                 .where(
                         ExamConfigurationMapRecordDynamicSqlSupport.examId,
                         SqlBuilder.isEqualTo(examId))
@@ -140,13 +140,14 @@ public class ExamConfigurationMapDAOImpl implements ExamConfigurationMapDAO {
                 .build()
                 .execute()
                 .stream()
+                .map(mapping -> mapping.getConfigurationNodeId())
                 .collect(Utils.toSingleton()));
     }
 
     @Override
     public Result<Long> getUserConfigurationIdForExam(final Long examId, final String userId) {
         return Result.tryCatch(() -> this.examConfigurationMapRecordMapper
-                .selectIdsByExample()
+                .selectByExample()
                 .where(
                         ExamConfigurationMapRecordDynamicSqlSupport.examId,
                         SqlBuilder.isEqualTo(examId))
@@ -156,6 +157,7 @@ public class ExamConfigurationMapDAOImpl implements ExamConfigurationMapDAO {
                 .build()
                 .execute()
                 .stream()
+                .map(mapping -> mapping.getConfigurationNodeId())
                 .collect(Utils.toSingleton()));
     }
 

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/sebconfig/SebExamConfigService.java

@@ -13,7 +13,6 @@ import java.io.OutputStream;
 import ch.ethz.seb.sebserver.gbl.api.APIMessage.FieldValidationException;
 import ch.ethz.seb.sebserver.gbl.model.sebconfig.ConfigurationTableValues;
 import ch.ethz.seb.sebserver.gbl.model.sebconfig.ConfigurationValue;
-import ch.ethz.seb.sebserver.gbl.util.Result;
 
 /** The base interface and service for all SEB Exam Configuration related functionality. */
 public interface SebExamConfigService {
@@ -32,10 +31,6 @@ public interface SebExamConfigService {
      * @throws FieldValidationException on validation exception */
     void validate(ConfigurationTableValues tableValue) throws FieldValidationException;
 
-    Result<Long> getDefaultConfigurationIdForExam(Long examId);
-
-    Result<Long> getUserConfigurationIdForExam(Long examId, String userId);
-
     /** Used to export a specified SEB Exam Configuration as plain XML
      * This exports the values of the follow-up configuration defined by a given
      * ConfigurationNode (configurationNodeId)
@@ -45,21 +40,26 @@ public interface SebExamConfigService {
      * @param configurationNodeId the identifier of the ConfigurationNode to export */
     void exportPlainXML(OutputStream out, Long institutionId, Long configurationNodeId);
 
-    /** Used to export a SEB Exam Configuration within its defined Configuration Exam Mapping.
+    /** Used to export the default SEB Exam Configuration for a given exam identifier.
      * either with encryption if defined or as plain text within the SEB Configuration format
      * as described here: https://www.safeexambrowser.org/developer/seb-file-format.html
      *
      * @param out The output stream to write the export data to
-     * @param configExamMappingId The identifier of the Exam Configuration Mapping */
+     * @param institutionId The identifier of the institution of the requesting user
-    void exportForExam(OutputStream out, Long configExamMappingId);
+     * @param examId the exam identifier */
+    default Long exportForExam(final OutputStream out, final Long institutionId, final Long examId) {
+        return exportForExam(out, institutionId, examId, null);
+    }
 
     /** Used to export the default SEB Exam Configuration for a given exam identifier.
      * either with encryption if defined or as plain text within the SEB Configuration format
      * as described here: https://www.safeexambrowser.org/developer/seb-file-format.html
      *
      * @param out The output stream to write the export data to
-     * @param examId the exam identifier */
+     * @param institutionId The identifier of the institution of the requesting user
-    void exportDefaultForExam(OutputStream out, Long examId);
+     * @param examId the exam identifier
+     * @param userId the user identifier if a specific user based configuration shall be exported */
+    Long exportForExam(OutputStream out, Long institutionId, Long examId, String userId);
 
     /** TODO */
     String generateConfigKey(Long configurationNodeId);

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/sebconfig/impl/ExamConfigIO.java

@@ -58,7 +58,11 @@ public class ExamConfigIO {
     }
 
     @Async(AsyncServiceSpringConfig.EXECUTOR_BEAN_NAME)
-    void exportPlainXML(final OutputStream out, final Long institutionId, final Long configurationNodeId) {
+    void exportPlainXML(
+            final OutputStream out,
+            final Long institutionId,
+            final Long configurationNodeId) {
+
         // get all defined root configuration attributes
         final Map<Long, ConfigurationAttribute> attributes = this.configurationAttributeDAO.getAllRootAttributes()
                 .getOrThrow()
@@ -112,7 +116,7 @@ public class ExamConfigIO {
             out.write(Constants.XML_PLIST_END_UTF_8);
             out.flush();
 
-        } catch (final IOException e) {
+        } catch (final Exception e) {
             log.error("Unexpected error while trying to write SEB Exam Configuration XML to output stream: ", e);
             try {
                 out.flush();

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/sebconfig/impl/SebExamConfigServiceImpl.java

@@ -15,6 +15,7 @@ import java.io.PipedOutputStream;
 import java.util.Collection;
 
 import org.apache.commons.io.IOUtils;
+import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.context.annotation.Lazy;
@@ -96,13 +97,16 @@ public class SebExamConfigServiceImpl implements SebExamConfigService {
             pout = new PipedOutputStream();
             pin = new PipedInputStream(pout);
 
-            this.examConfigIO.exportPlainXML(pout, institutionId, configurationNodeId);
+            this.examConfigIO.exportPlainXML(
+                    pout,
+                    institutionId,
+                    configurationNodeId);
 
             IOUtils.copyLarge(pin, out);
 
-            pin.close();
             pout.flush();
             pout.close();
+            pin.close();
 
         } catch (final IOException e) {
             log.error("Error while stream plain text SEB clonfiguration data: ", e);
@@ -127,26 +131,32 @@ public class SebExamConfigServiceImpl implements SebExamConfigService {
 
     }
 
-    @Override
     public Result<Long> getDefaultConfigurationIdForExam(final Long examId) {
         return this.examConfigurationMapDAO.getDefaultConfigurationForExam(examId);
     }
 
-    @Override
     public Result<Long> getUserConfigurationIdForExam(final Long examId, final String userId) {
         return this.examConfigurationMapDAO.getUserConfigurationIdForExam(examId, userId);
     }
 
     @Override
-    public void exportForExam(final OutputStream out, final Long configExamMappingId) {
+    public Long exportForExam(
-        // TODO Auto-generated method stub
+            final OutputStream out,
+            final Long institutionId,
+            final Long examId,
+            final String userId) {
 
-    }
+        final Long configurationNodeId = (StringUtils.isBlank(userId))
+                ? getDefaultConfigurationIdForExam(examId)
+                        .getOrThrow()
+                : getUserConfigurationIdForExam(examId, userId)
+                        .getOrThrow();
 
-    @Override
+        // TODO add header, zip and encrypt if needed
-    public void exportDefaultForExam(final OutputStream out, final Long examId) {
-        // TODO Auto-generated method stub
 
+        this.exportPlainXML(out, institutionId, configurationNodeId);
+
+        return configurationNodeId;
     }
 
     @Override

src/main/java/ch/ethz/seb/sebserver/webservice/servicelayer/sebconfig/impl/converter/IntegerConverter.java

@@ -65,5 +65,4 @@ public class IntegerConverter implements XMLValueConverter {
         }
 
     }
-
 }

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

@@ -20,4 +20,8 @@ public interface EventHandlingStrategy extends Consumer<ClientEvent> {
     String EVENT_CONSUMER_STRATEGY_SINGLE_EVENT_STORE = "SINGLE_EVENT_STORE_STRATEGY";
     String EVENT_CONSUMER_STRATEGY_ASYNC_BATCH_STORE = "ASYNC_BATCH_STORE_STRATEGY";
 
+    void enable();
+
+    void disable();
+
 }

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

@@ -39,6 +39,10 @@ public interface ExamSessionService {
      *         happened. */
     Result<Collection<Exam>> getRunningExamsForInstitution(Long institutionId);
 
-    void streamDefaultExamConfig(Long institutionId, String connectionToken, OutputStream out);
+    /** Streams the default SEB Exam Configuration to a ClientConnection with given connectionToken.
+     *
+     * @param connectionToken The connection token that identifiers the ClientConnection
+     * @param out The OutputStream to stream the data to */
+    void streamDefaultExamConfig(String connectionToken, OutputStream out);
 
 }

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

@@ -55,8 +55,8 @@ public interface SebClientConnectionService {
     Result<ClientConnection> updateClientConnection(
             String connectionToken,
             Long institutionId,
-            String clientAddress,
             Long examId,
+            String clientAddress,
             String userSessionId);
 
     /** This is used to establish a already created ClientConnection and set it to sate: ESTABLISHED

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

@@ -51,7 +51,7 @@ public abstract class AbstractClientIndicator implements ClientIndicator {
 
     @Override
     public double getValue() {
-        if (this.currentValue == Double.NaN || !this.cachingEnabled) {
+        if (Double.isNaN(this.currentValue) || !this.cachingEnabled) {
             this.currentValue = computeValueAt(DateTime.now(DateTimeZone.UTC).getMillis());
         }
 

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

@@ -12,6 +12,8 @@ import java.util.Collections;
 import java.util.EnumSet;
 import java.util.Set;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
 import ch.ethz.seb.sebserver.gbl.model.session.ClientEvent.EventType;
 
 public abstract class AbstractPingIndicator extends AbstractClientIndicator {
@@ -37,4 +39,14 @@ public abstract class AbstractPingIndicator extends AbstractClientIndicator {
         return this.EMPTY_SET;
     }
 
+    @JsonIgnore
+    public int getPingCount() {
+        return this.pingCount;
+    }
+
+    @JsonIgnore
+    public int getPingNumber() {
+        return this.pingNumber;
+    }
+
 }

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

@@ -62,6 +62,7 @@ public class AsyncBatchEventSaveStrategy implements EventHandlingStrategy {
 
     private final BlockingDeque<ClientEvent> eventQueue = new LinkedBlockingDeque<>();
     private boolean workersRunning = false;
+    private boolean enabled = false;
 
     public AsyncBatchEventSaveStrategy(
             final SqlSessionFactory sqlSessionFactory,
@@ -75,9 +76,22 @@ public class AsyncBatchEventSaveStrategy implements EventHandlingStrategy {
         this.transactionTemplate.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRES_NEW);
     }
 
+    @Override
+    public void enable() {
+        this.enabled = true;
+
+    }
+
+    @Override
+    public void disable() {
+        this.enabled = false;
+    }
+
     @EventListener(ApplicationReadyEvent.class)
     protected void recover() {
-        runWorkers();
+        if (this.enabled) {
+            runWorkers();
+        }
     }
 
     @Override

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

@@ -52,6 +52,10 @@ public class ClientIndicatorFactory {
     public Collection<ClientIndicator> createFor(final ClientConnection clientConnection) {
         final List<ClientIndicator> result = new ArrayList<>();
 
+        if (clientConnection.examId == null) {
+            return result;
+        }
+
         try {
 
             final Collection<Indicator> examIndicators = this.indicatorDAO

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

@@ -8,13 +8,8 @@
 
 package ch.ethz.seb.sebserver.webservice.servicelayer.session.impl;
 
-import java.io.BufferedInputStream;
 import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.PipedInputStream;
-import java.io.PipedOutputStream;
 
-import org.apache.tomcat.util.http.fileupload.IOUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.cache.annotation.CacheEvict;
@@ -24,7 +19,6 @@ import org.springframework.stereotype.Service;
 
 import ch.ethz.seb.sebserver.gbl.model.exam.Exam;
 import ch.ethz.seb.sebserver.gbl.model.session.ClientConnection;
-import ch.ethz.seb.sebserver.gbl.model.session.ClientConnection.ConnectionStatus;
 import ch.ethz.seb.sebserver.gbl.profile.WebServiceProfile;
 import ch.ethz.seb.sebserver.gbl.util.Result;
 import ch.ethz.seb.sebserver.webservice.servicelayer.dao.ClientConnectionDAO;
@@ -63,7 +57,7 @@ public class ExamSessionCacheService {
             cacheNames = CACHE_NAME_RUNNING_EXAM,
             key = "#examId",
             unless = "#result == null")
-    Exam getRunningExam(final Long examId) {
+    public Exam getRunningExam(final Long examId) {
 
         if (log.isDebugEnabled()) {
             log.debug("Verify running exam for id: {}" + examId);
@@ -87,7 +81,7 @@ public class ExamSessionCacheService {
             cacheNames = CACHE_NAME_RUNNING_EXAM,
             key = "#exam.id",
             condition = "#target.isRunning(#result)")
-    Exam evict(final Exam exam) {
+    public Exam evict(final Exam exam) {
 
         if (log.isDebugEnabled()) {
             log.debug("Conditional eviction of running Exam from cache: {}", isRunning(exam));
@@ -108,7 +102,7 @@ public class ExamSessionCacheService {
             cacheNames = CACHE_NAME_ACTIVE_CLIENT_CONNECTION,
             key = "#connectionToken",
             unless = "#result == null")
-    ClientConnectionDataInternal getActiveClientConnection(final String connectionToken) {
+    public ClientConnectionDataInternal getActiveClientConnection(final String connectionToken) {
 
         if (log.isDebugEnabled()) {
             log.debug("Verify ClientConnection for running exam for caching by connectionToken: ", connectionToken);
@@ -123,20 +117,6 @@ public class ExamSessionCacheService {
         }
 
         final ClientConnection clientConnection = byPK.get();
-
-        // verify connection is established
-        if (clientConnection.status != ConnectionStatus.ESTABLISHED) {
-            log.error("Illegal state: ClientConnection is not in expected state; ESTABLISHED. ClientConnection: ",
-                    clientConnection);
-            return null;
-        }
-
-        // verify exam is running
-        if (getRunningExam(clientConnection.examId) == null) {
-            log.error("Exam for ClientConnection with id { is not currently running}", clientConnection.id);
-            return null;
-        }
-
         return new ClientConnectionDataInternal(
                 clientConnection,
                 this.clientIndicatorFactory.createFor(clientConnection));
@@ -145,7 +125,7 @@ public class ExamSessionCacheService {
     @CacheEvict(
             cacheNames = CACHE_NAME_ACTIVE_CLIENT_CONNECTION,
             key = "#connectionToken")
-    void evictClientConnection(final String connectionToken) {
+    public void evictClientConnection(final String connectionToken) {
         if (log.isDebugEnabled()) {
             log.debug("Eviction of ClientConnectionData from cache: {}", connectionToken);
         }
@@ -155,25 +135,20 @@ public class ExamSessionCacheService {
             cacheNames = CACHE_NAME_SEB_CONFIG_EXAM,
             key = "#examId",
             unless = "#result == null")
-    InMemorySebConfig getDefaultSebConfigForExam(final Long examId) {
+    public InMemorySebConfig getDefaultSebConfigForExam(final Long examId) {
         final Exam runningExam = this.getRunningExam(examId);
-        final PipedOutputStream pipOut = new PipedOutputStream();
+
         try {
-            final Long configId = this.sebExamConfigService
-                    .getDefaultConfigurationIdForExam(runningExam.id)
-                    .getOrThrow();
-
-            // TODO add header, zip and encrypt if needed
-
-            final BufferedInputStream in = new BufferedInputStream(new PipedInputStream(pipOut));
-            this.sebExamConfigService.exportPlainXML(pipOut, runningExam.institutionId, configId);
 
             final ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
-            IOUtils.copyLarge(in, byteOut);
+            final Long configId = this.sebExamConfigService.exportForExam(
+                    byteOut,
+                    runningExam.institutionId,
+                    examId);
 
             return new InMemorySebConfig(configId, runningExam.id, byteOut.toByteArray());
 
-        } catch (final IOException e) {
+        } catch (final Exception e) {
             log.error("Unexpected error while getting default exam configuration for running exam; {}", runningExam, e);
             return null;
         }
@@ -182,7 +157,7 @@ public class ExamSessionCacheService {
     @CacheEvict(
             cacheNames = CACHE_NAME_SEB_CONFIG_EXAM,
             key = "#examId")
-    void evictDefaultSebConfig(final Long examId) {
+    public void evictDefaultSebConfig(final Long examId) {
         if (log.isDebugEnabled()) {
             log.debug("Eviction of default SEB Configuration from cache for exam: {}", examId);
         }

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

@@ -11,6 +11,7 @@ package ch.ethz.seb.sebserver.webservice.servicelayer.session.impl;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.NoSuchElementException;
 import java.util.stream.Collectors;
 
@@ -71,7 +72,7 @@ public class ExamSessionServiceImpl implements ExamSessionService {
             return Result.of(exam);
         } else {
             if (exam != null) {
-                this.examSessionCacheService.evict(exam);
+                flushCache(exam);
             }
 
             log.warn("Exam {} is not currently running", examId);
@@ -92,7 +93,6 @@ public class ExamSessionServiceImpl implements ExamSessionService {
 
     @Override
     public void streamDefaultExamConfig(
-            final Long institutionId,
             final String connectionToken,
             final OutputStream out) {
 
@@ -101,7 +101,7 @@ public class ExamSessionServiceImpl implements ExamSessionService {
         }
 
         final ClientConnection connection = this.clientConnectionDAO
-                .byConnectionToken(institutionId, connectionToken)
+                .byConnectionToken(connectionToken)
                 .getOrThrow();
 
         if (connection == null || connection.status != ConnectionStatus.ESTABLISHED) {
@@ -111,17 +111,15 @@ public class ExamSessionServiceImpl implements ExamSessionService {
         }
 
         if (log.isDebugEnabled()) {
-            log.debug("SEB exam configuration download request: {}", connection);
+            log.debug("Trying to get exam from InMemorySebConfig");
-            log.debug("Trying to get exam form InMemorySebConfig");
         }
 
         final InMemorySebConfig sebConfigForExam = this.examSessionCacheService
                 .getDefaultSebConfigForExam(connection.examId);
 
-        if (log.isDebugEnabled()) {
+        if (sebConfigForExam == null) {
-            if (sebConfigForExam == null) {
+            log.error("Failed to get and cache InMemorySebConfig for connection: {}", connection);
-                log.debug("Failed to get and cache InMemorySebConfig for connection: {}", connection);
+            return;
-            }
         }
 
         try {
@@ -141,4 +139,13 @@ public class ExamSessionServiceImpl implements ExamSessionService {
         }
     }
 
+    private void flushCache(final Exam exam) {
+        this.examSessionCacheService.evict(exam);
+        this.examSessionCacheService.evictDefaultSebConfig(exam.id);
+        this.clientConnectionDAO
+                .getConnectionTokens(exam.id)
+                .getOrElse(() -> Collections.emptyList())
+                .forEach(token -> this.examSessionCacheService.evictClientConnection(token));
+    }
+
 }

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

@@ -62,6 +62,7 @@ public class SebClientConnectionServiceImpl implements SebClientConnectionServic
         this.eventHandlingStrategy = applicationContext.getBean(
                 eventHandlingStrategyProperty,
                 EventHandlingStrategy.class);
+        this.eventHandlingStrategy.enable();
     }
 
     @Override
@@ -90,15 +91,23 @@ public class SebClientConnectionServiceImpl implements SebClientConnectionServic
                     null,
                     institutionId,
                     examId,
-                    ClientConnection.ConnectionStatus.CONNECTION_REQUESTED,
+                    ConnectionStatus.CONNECTION_REQUESTED,
                     connectionToken,
                     null,
                     clientAddress,
                     null))
                     .getOrThrow();
 
-            if (log.isDebugEnabled()) {
+            // load client connection data into cache
-                log.debug("New ClientConnection created: {}", clientConnection);
+            final ClientConnectionDataInternal activeClientConnection = this.examSessionCacheService
+                    .getActiveClientConnection(connectionToken);
+
+            if (activeClientConnection == null) {
+                log.warn("Failed to load ClientConnectionDataInternal into cache on update");
+            } else {
+                if (log.isDebugEnabled()) {
+                    log.debug("New ClientConnection created: {}", clientConnection);
+                }
             }
 
             return clientConnection;
@@ -109,8 +118,8 @@ public class SebClientConnectionServiceImpl implements SebClientConnectionServic
     public Result<ClientConnection> updateClientConnection(
             final String connectionToken,
             final Long institutionId,
-            final String clientAddress,
             final Long examId,
+            final String clientAddress,
             final String userSessionId) {
 
         return Result.tryCatch(() -> {
@@ -131,9 +140,7 @@ public class SebClientConnectionServiceImpl implements SebClientConnectionServic
 
             checkExamRunning(examId);
 
-            final ClientConnection clientConnection = getClientConnection(
+            final ClientConnection clientConnection = getClientConnection(connectionToken);
-                    connectionToken,
-                    institutionId);
 
             checkInstitutionalIntegrity(
                     institutionId,
@@ -156,7 +163,15 @@ public class SebClientConnectionServiceImpl implements SebClientConnectionServic
                             virtualClientAddress))
                     .getOrThrow();
 
-            if (log.isDebugEnabled()) {
+            // evict cached ClientConnection
+            this.examSessionCacheService.evictClientConnection(connectionToken);
+            // and load updated ClientConnection into cache
+            final ClientConnectionDataInternal activeClientConnection = this.examSessionCacheService
+                    .getActiveClientConnection(connectionToken);
+
+            if (activeClientConnection == null) {
+                log.warn("Failed to load ClientConnectionDataInternal into cache on update");
+            } else if (log.isDebugEnabled()) {
                 log.debug("SEB client connection, successfully updated ClientConnection: {}",
                         updatedClientConnection);
             }
@@ -192,9 +207,7 @@ public class SebClientConnectionServiceImpl implements SebClientConnectionServic
 
             checkExamRunning(examId);
 
-            final ClientConnection clientConnection = getClientConnection(
+            final ClientConnection clientConnection = getClientConnection(connectionToken);
-                    connectionToken,
-                    institutionId);
 
             checkInstitutionalIntegrity(
                     institutionId,
@@ -217,42 +230,40 @@ public class SebClientConnectionServiceImpl implements SebClientConnectionServic
                     clientConnection.id,
                     null,
                     examId,
-                    ClientConnection.ConnectionStatus.ESTABLISHED,
+                    ConnectionStatus.ESTABLISHED,
                     null,
                     userSessionId,
                     null,
                     virtualClientAddress);
 
             // ClientConnection integrity
-            if (establishedClientConnection.institutionId == null ||
+            if (clientConnection.institutionId == null ||
+                    clientConnection.connectionToken == null ||
                     establishedClientConnection.examId == null ||
-                    establishedClientConnection.clientAddress == null ||
+                    clientConnection.clientAddress == null ||
-                    establishedClientConnection.connectionToken == null) {
+                    establishedClientConnection.status != ConnectionStatus.ESTABLISHED) {
 
-                log.error("ClientConnection integrity violation: {}", establishedClientConnection);
+                log.error("ClientConnection integrity violation, clientConnection: {}, establishedClientConnection: {}",
-                throw new IllegalStateException("ClientConnection integrity violation: " + establishedClientConnection);
+                        clientConnection,
+                        establishedClientConnection);
+                throw new IllegalStateException("ClientConnection integrity violation");
             }
 
             final ClientConnection updatedClientConnection = this.clientConnectionDAO
                     .save(establishedClientConnection)
                     .getOrThrow();
 
-            if (updatedClientConnection.status == ConnectionStatus.ESTABLISHED) {
+            // evict cached ClientConnection
-                // load into cache...
+            this.examSessionCacheService.evictClientConnection(connectionToken);
-                final ClientConnectionDataInternal activeClientConnection = this.examSessionCacheService
+            // and load updated ClientConnection into cache
-                        .getActiveClientConnection(updatedClientConnection.connectionToken);
+            final ClientConnectionDataInternal activeClientConnection = this.examSessionCacheService
+                    .getActiveClientConnection(connectionToken);
 
-                if (activeClientConnection == null) {
+            if (activeClientConnection == null) {
-                    log.warn("Unable to access and cache ClientConnection");
+                log.warn("Failed to load ClientConnectionDataInternal into cache on update");
-                }
+            } else if (log.isDebugEnabled()) {
-
+                log.debug("SEB client connection, successfully established ClientConnection: {}",
-                if (log.isDebugEnabled()) {
+                        updatedClientConnection);
-                    log.debug("ClientConnection: {} successfully established", clientConnection);
-                }
-            } else {
-                if (log.isDebugEnabled()) {
-                    log.debug("ClientConnection: {} updated", clientConnection);
-                }
             }
 
             return updatedClientConnection;
@@ -278,18 +289,14 @@ public class SebClientConnectionServiceImpl implements SebClientConnectionServic
             }
 
             final ClientConnection clientConnection = this.clientConnectionDAO
-                    .byConnectionToken(institutionId, connectionToken)
+                    .byConnectionToken(connectionToken)
                     .getOrThrow();
 
-            // evict ClientConnection from cache
-            this.examSessionCacheService
-                    .evictClientConnection(clientConnection.connectionToken);
-
             final ClientConnection updatedClientConnection = this.clientConnectionDAO.save(new ClientConnection(
                     clientConnection.id,
                     null,
                     null,
-                    ClientConnection.ConnectionStatus.CLOSED,
+                    ConnectionStatus.CLOSED,
                     null,
                     null,
                     null,
@@ -300,6 +307,11 @@ public class SebClientConnectionServiceImpl implements SebClientConnectionServic
                         clientConnection);
             }
 
+            // evict cached ClientConnection
+            this.examSessionCacheService.evictClientConnection(connectionToken);
+            // and load updated ClientConnection into cache
+            this.examSessionCacheService.getActiveClientConnection(connectionToken);
+
             return updatedClientConnection;
         });
 
@@ -326,12 +338,27 @@ public class SebClientConnectionServiceImpl implements SebClientConnectionServic
             final String connectionToken,
             final ClientEvent event) {
 
-        this.eventHandlingStrategy.accept(event);
-
         final ClientConnectionDataInternal activeClientConnection =
                 this.examSessionCacheService.getActiveClientConnection(connectionToken);
 
         if (activeClientConnection != null) {
+            if (activeClientConnection.clientConnection.status != ConnectionStatus.ESTABLISHED) {
+                throw new IllegalStateException("ClientConnection is not fully established or closed");
+            }
+
+            // store event
+            this.eventHandlingStrategy.accept(
+                    (event.connectionId != null)
+                            ? event
+                            : new ClientEvent(
+                                    null,
+                                    activeClientConnection.getConnectionId(),
+                                    event.eventType,
+                                    event.timestamp,
+                                    event.numValue,
+                                    event.text));
+
+            // update indicators
             activeClientConnection.getindicatorMapping(event.eventType)
                     .stream()
                     .forEach(indicator -> indicator.notifyValueChange(event));
@@ -344,9 +371,9 @@ public class SebClientConnectionServiceImpl implements SebClientConnectionServic
         }
     }
 
-    private ClientConnection getClientConnection(final String connectionToken, final Long institutionId) {
+    private ClientConnection getClientConnection(final String connectionToken) {
         final ClientConnection clientConnection = this.clientConnectionDAO
-                .byConnectionToken(institutionId, connectionToken)
+                .byConnectionToken(connectionToken)
                 .getOrThrow();
         return clientConnection;
     }

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

@@ -30,6 +30,7 @@ import ch.ethz.seb.sebserver.webservice.servicelayer.session.EventHandlingStrate
 public class SingleEventSaveStrategy implements EventHandlingStrategy {
 
     private final ClientEventDAO clientEventDAO;
+    private boolean enabled = false;
 
     public SingleEventSaveStrategy(final ClientEventDAO clientEventDAO) {
         this.clientEventDAO = clientEventDAO;
@@ -37,7 +38,24 @@ public class SingleEventSaveStrategy implements EventHandlingStrategy {
 
     @Override
     public void accept(final ClientEvent event) {
-        this.clientEventDAO.save(event);
+        this.clientEventDAO
+                .createNew(event)
+                .getOrThrow();
+    }
+
+    @Override
+    public void enable() {
+        this.enabled = true;
+
+    }
+
+    @Override
+    public void disable() {
+        this.enabled = false;
+    }
+
+    public boolean isEnabled() {
+        return this.enabled;
     }
 
 }

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

@@ -24,6 +24,7 @@ import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestHeader;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RequestParam;
@@ -31,6 +32,8 @@ import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
 import ch.ethz.seb.sebserver.gbl.api.API;
+import ch.ethz.seb.sebserver.gbl.api.APIMessage;
+import ch.ethz.seb.sebserver.gbl.api.JSONMapper;
 import ch.ethz.seb.sebserver.gbl.api.POSTMapper;
 import ch.ethz.seb.sebserver.gbl.model.exam.Exam;
 import ch.ethz.seb.sebserver.gbl.model.session.ClientConnection;
@@ -38,6 +41,7 @@ import ch.ethz.seb.sebserver.gbl.model.session.ClientEvent;
 import ch.ethz.seb.sebserver.gbl.model.session.PingResponse;
 import ch.ethz.seb.sebserver.gbl.model.session.RunningExam;
 import ch.ethz.seb.sebserver.gbl.profile.WebServiceProfile;
+import ch.ethz.seb.sebserver.gbl.util.Utils;
 import ch.ethz.seb.sebserver.webservice.servicelayer.dao.ExamDAO;
 import ch.ethz.seb.sebserver.webservice.servicelayer.dao.SebClientConfigDAO;
 import ch.ethz.seb.sebserver.webservice.servicelayer.session.ExamSessionService;
@@ -54,17 +58,20 @@ public class ExamAPI_V1_Controller {
     private final ExamSessionService examSessionService;
     private final SebClientConnectionService sebClientConnectionService;
     private final SebClientConfigDAO sebClientConfigDAO;
+    private final JSONMapper jsonMapper;
 
     protected ExamAPI_V1_Controller(
             final ExamDAO examDAO,
             final ExamSessionService examSessionService,
             final SebClientConnectionService sebClientConnectionService,
-            final SebClientConfigDAO sebClientConfigDAO) {
+            final SebClientConfigDAO sebClientConfigDAO,
+            final JSONMapper jsonMapper) {
 
         this.examDAO = examDAO;
         this.examSessionService = examSessionService;
         this.sebClientConnectionService = sebClientConnectionService;
         this.sebClientConfigDAO = sebClientConfigDAO;
+        this.jsonMapper = jsonMapper;
     }
 
     @RequestMapping(
@@ -143,8 +150,8 @@ public class ExamAPI_V1_Controller {
             method = RequestMethod.PATCH,
             consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE)
     public void handshakeUpdate(
+            @RequestHeader(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken,
             @RequestParam(name = API.EXAM_API_PARAM_EXAM_ID, required = false) final Long examId,
-            @RequestParam(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken,
             @RequestParam(name = API.EXAM_API_USER_SESSION_ID, required = false) final String userSessionId,
             final Principal principal,
             final HttpServletRequest request) {
@@ -164,7 +171,7 @@ public class ExamAPI_V1_Controller {
                     remoteAddr);
         }
 
-        this.sebClientConnectionService.establishClientConnection(
+        this.sebClientConnectionService.updateClientConnection(
                 connectionToken,
                 institutionId,
                 examId,
@@ -178,8 +185,8 @@ public class ExamAPI_V1_Controller {
             method = RequestMethod.PUT,
             consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE)
     public void handshakeEstablish(
+            @RequestHeader(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken,
             @RequestParam(name = API.EXAM_API_PARAM_EXAM_ID, required = false) final Long examId,
-            @RequestParam(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken,
             @RequestParam(name = API.EXAM_API_USER_SESSION_ID, required = false) final String userSessionId,
             final Principal principal,
             final HttpServletRequest request) {
@@ -210,8 +217,8 @@ public class ExamAPI_V1_Controller {
             path = API.EXAM_API_HANDSHAKE_ENDPOINT,
             method = RequestMethod.DELETE,
             consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE)
-    public void handshakeEstablish(
+    public void handshakeDelete(
-            @RequestParam(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken,
+            @RequestHeader(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken,
             final Principal principal,
             final HttpServletRequest request) {
 
@@ -239,25 +246,30 @@ public class ExamAPI_V1_Controller {
             consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE,
             produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)
     public ResponseEntity<StreamingResponseBody> getConfig(
-            @RequestParam(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken,
+            @RequestHeader(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken) {
-            final Principal principal) {
 
-        final Long institutionId = getInstitutionId(principal);
+        final StreamingResponseBody stream = out -> {
-        final StreamingResponseBody stream = out -> this.examSessionService.streamDefaultExamConfig(
+            try {
-                institutionId,
+                this.examSessionService
-                connectionToken,
+                        .streamDefaultExamConfig(
-                out);
+                                connectionToken,
+                                out);
+            } catch (final Exception e) {
+                final APIMessage errorMessage = APIMessage.ErrorMessage.GENERIC.of(e.getMessage());
+                out.write(Utils.toByteArray(this.jsonMapper.writeValueAsString(errorMessage)));
+            }
+        };
 
         return new ResponseEntity<>(stream, HttpStatus.OK);
     }
 
     @RequestMapping(
             path = API.EXAM_API_PING_ENDPOINT,
-            method = RequestMethod.PUT,
+            method = RequestMethod.POST,
             consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE,
             produces = MediaType.APPLICATION_JSON_UTF8_VALUE)
     public PingResponse ping(
-            @RequestParam(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken,
+            @RequestHeader(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken,
             @RequestParam(name = API.EXAM_API_PING_TIMESTAMP, required = true) final long timestamp,
             @RequestParam(name = API.EXAM_API_PING_NUMBER, required = false) final int pingNumber) {
 
@@ -272,9 +284,9 @@ public class ExamAPI_V1_Controller {
     @RequestMapping(
             path = API.EXAM_API_EVENT_ENDPOINT,
             method = RequestMethod.POST,
-            consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE)
+            consumes = MediaType.APPLICATION_JSON_UTF8_VALUE)
     public void event(
-            @RequestParam(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken,
+            @RequestHeader(name = API.EXAM_API_SEB_CONNECTION_TOKEN, required = true) final String connectionToken,
             @RequestBody(required = true) final ClientEvent event) {
 
         this.sebClientConnectionService.notifyClientEvent(connectionToken, event);

src/test/java/ch/ethz/seb/sebserver/webservice/integration/api/exam/ExamAPIAccessTokenRequestTest.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2019 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.webservice.integration.api.exam;
+
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Test;
+import org.springframework.test.context.jdbc.Sql;
+
+@Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+public class ExamAPIAccessTokenRequestTest extends ExamAPIIntegrationTester {
+
+    @Test
+    public void testRequestAccessToken() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+    }
+
+}

src/test/java/ch/ethz/seb/sebserver/webservice/integration/api/exam/ExamAPIIntegrationTester.java

@@ -9,12 +9,15 @@
 package ch.ethz.seb.sebserver.webservice.integration.api.exam;
 
 import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.httpBasic;
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
 import java.util.Collections;
 
+import org.apache.commons.lang3.StringUtils;
+import org.joda.time.DateTime;
+import org.joda.time.DateTimeZone;
 import org.junit.Before;
 import org.junit.runner.RunWith;
 import org.mockito.Mockito;
@@ -25,6 +28,9 @@ import org.springframework.boot.json.JacksonJsonParser;
 import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.cache.CacheManager;
+import org.springframework.http.MediaType;
+import org.springframework.mock.web.MockHttpServletResponse;
 import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.security.oauth2.provider.ClientDetails;
 import org.springframework.security.oauth2.provider.client.BaseClientDetails;
@@ -32,7 +38,9 @@ import org.springframework.security.web.FilterChainProxy;
 import org.springframework.test.context.ActiveProfiles;
 import org.springframework.test.context.junit4.SpringRunner;
 import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.MvcResult;
 import org.springframework.test.web.servlet.ResultActions;
+import org.springframework.test.web.servlet.request.MockHttpServletRequestBuilder;
 import org.springframework.test.web.servlet.setup.MockMvcBuilders;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
@@ -40,6 +48,7 @@ import org.springframework.web.context.WebApplicationContext;
 
 import ch.ethz.seb.sebserver.SEBServer;
 import ch.ethz.seb.sebserver.WebSecurityConfig;
+import ch.ethz.seb.sebserver.gbl.api.API;
 import ch.ethz.seb.sebserver.gbl.api.JSONMapper;
 import ch.ethz.seb.sebserver.webservice.servicelayer.sebconfig.SebClientConfigService;
 import ch.ethz.seb.sebserver.webservice.weblayer.oauth.AdminAPIClientDetails;
@@ -66,6 +75,9 @@ public abstract class ExamAPIIntegrationTester {
 
     protected MockMvc mockMvc;
 
+    @Autowired
+    protected CacheManager cacheManager;
+
     @MockBean
     public WebClientDetailsService webClientDetailsService;
 
@@ -75,6 +87,12 @@ public abstract class ExamAPIIntegrationTester {
                 .addFilter(this.springSecurityFilterChain).build();
         Mockito.when(this.webClientDetailsService.loadClientByClientId(Mockito.anyString())).thenReturn(
                 getForExamClientAPI());
+
+        // clear all caches before a test
+        this.cacheManager.getCacheNames()
+                .stream()
+                .map(name -> this.cacheManager.getCache(name))
+                .forEach(cache -> cache.clear());
     }
 
     protected ClientDetails getForExamClientAPI() {
@@ -103,9 +121,9 @@ public abstract class ExamAPIIntegrationTester {
         final ResultActions result = this.mockMvc.perform(post("/oauth/token")
                 .params(params)
                 .with(httpBasic(clientId, clientSecret))
-                .accept("application/json;charset=UTF-8"))
+                .accept(MediaType.APPLICATION_JSON_UTF8_VALUE))
                 .andExpect(status().isOk())
-                .andExpect(content().contentType("application/json;charset=UTF-8"));
+                .andExpect(content().contentType(MediaType.APPLICATION_JSON_UTF8_VALUE));
 
         final String resultString = result.andReturn().getResponse().getContentAsString();
 
@@ -113,6 +131,152 @@ public abstract class ExamAPIIntegrationTester {
         return jsonParser.parseMap(resultString).get("access_token").toString();
     }
 
+    protected MockHttpServletResponse createConnection(
+            final String accessToken,
+            final Long institutionId,
+            final Long examId) throws Exception {
+
+        final MockHttpServletRequestBuilder builder = get(this.endpoint + "/handshake")
+                .header("Content-Type", "application/x-www-form-urlencoded")
+                .header("Authorization", "Bearer " + accessToken)
+                .accept(MediaType.APPLICATION_JSON_UTF8_VALUE);
+
+        String body = "";
+
+        if (institutionId != null) {
+            body += "institutionId=" + institutionId;
+        }
+        if (examId != null) {
+            body += "&examId=" + examId;
+        }
+
+        builder.content(body);
+
+        final ResultActions result = this.mockMvc.perform(builder)
+                .andExpect(content().contentType(MediaType.APPLICATION_JSON_UTF8_VALUE));
+
+        return result.andReturn().getResponse();
+    }
+
+    protected MockHttpServletResponse updateConnection(
+            final String accessToken,
+            final String connectionToken,
+            final Long examId,
+            final String userSessionId) throws Exception {
+
+        return updateConnection(accessToken, connectionToken, examId, userSessionId, false);
+    }
+
+    protected MockHttpServletResponse establishConnection(
+            final String accessToken,
+            final String connectionToken,
+            final Long examId,
+            final String userSessionId) throws Exception {
+
+        return updateConnection(accessToken, connectionToken, examId, userSessionId, true);
+    }
+
+    protected MockHttpServletResponse updateConnection(
+            final String accessToken,
+            final String connectionToken,
+            final Long examId,
+            final String userSessionId,
+            final boolean establish) throws Exception {
+
+        final MockHttpServletRequestBuilder builder = (establish)
+                ? put(this.endpoint + "/handshake")
+                        .header("Content-Type", MediaType.APPLICATION_FORM_URLENCODED_VALUE)
+                        .header("Authorization", "Bearer " + accessToken)
+                        .header(API.EXAM_API_SEB_CONNECTION_TOKEN, connectionToken)
+                        .accept(MediaType.APPLICATION_JSON_UTF8_VALUE)
+                : patch(this.endpoint + "/handshake")
+                        .header("Content-Type", MediaType.APPLICATION_FORM_URLENCODED_VALUE)
+                        .header("Authorization", "Bearer " + accessToken)
+                        .header(API.EXAM_API_SEB_CONNECTION_TOKEN, connectionToken)
+                        .accept(MediaType.APPLICATION_JSON_UTF8_VALUE);
+
+        String body = "";
+        if (examId != null) {
+            body += "examId=" + examId;
+        }
+        if (userSessionId != null) {
+            if (!StringUtils.isBlank(body)) {
+                body += "&";
+            }
+
+            body += API.EXAM_API_USER_SESSION_ID + "=" + userSessionId;
+        }
+        builder.content(body);
+
+        final ResultActions result = this.mockMvc.perform(builder);
+
+        return result.andReturn().getResponse();
+    }
+
+    protected MockHttpServletResponse closeConnection(final String accessToken, final String connectionToken)
+            throws Exception {
+        final MockHttpServletRequestBuilder builder = delete(this.endpoint + "/handshake")
+                .header("Content-Type", MediaType.APPLICATION_FORM_URLENCODED_VALUE)
+                .header("Authorization", "Bearer " + accessToken)
+                .header(API.EXAM_API_SEB_CONNECTION_TOKEN, connectionToken)
+                .accept(MediaType.APPLICATION_JSON_UTF8_VALUE);
+        final ResultActions result = this.mockMvc.perform(builder);
+        return result.andReturn().getResponse();
+    }
+
+    protected MockHttpServletResponse sendPing(
+            final String accessToken,
+            final String connectionToken,
+            final int num) throws Exception {
+        final MockHttpServletRequestBuilder builder = post(this.endpoint + API.EXAM_API_PING_ENDPOINT)
+                .header("Content-Type", MediaType.APPLICATION_FORM_URLENCODED_VALUE)
+                .header("Authorization", "Bearer " + accessToken)
+                .header(API.EXAM_API_SEB_CONNECTION_TOKEN, connectionToken)
+                .accept(MediaType.APPLICATION_JSON_UTF8_VALUE);
+
+        final String body = API.EXAM_API_PING_TIMESTAMP + "=" + DateTime.now(DateTimeZone.UTC).getMillis()
+                + "&" + API.EXAM_API_PING_NUMBER + "=" + num;
+        builder.content(body);
+
+        final ResultActions result = this.mockMvc.perform(builder);
+        return result.andReturn().getResponse();
+    }
+
+    protected MockHttpServletResponse sendEvent(
+            final String accessToken,
+            final String connectionToken,
+            final String type,
+            final long timestamp,
+            final double value,
+            final String text) throws Exception {
+
+        final MockHttpServletRequestBuilder builder = post(this.endpoint + API.EXAM_API_EVENT_ENDPOINT)
+                .header("Content-Type", MediaType.APPLICATION_JSON_UTF8_VALUE)
+                .header("Authorization", "Bearer " + accessToken)
+                .header(API.EXAM_API_SEB_CONNECTION_TOKEN, connectionToken)
+                .accept(MediaType.APPLICATION_JSON_UTF8_VALUE);
+
+        final String body = "{ \"type\": \"%s\", \"timestamp\": %s, \"numericValue\": %s, \"text\": \"%s\" }";
+        builder.content(String.format(body, type, timestamp, value, text));
+        final ResultActions result = this.mockMvc.perform(builder);
+        return result.andReturn().getResponse();
+    }
+
+    protected MockHttpServletResponse getExamConfig(final String accessToken, final String connectionToken)
+            throws Exception {
+        final MockHttpServletRequestBuilder builder = get(this.endpoint + API.EXAM_API_CONFIGURATION_REQUEST_ENDPOINT)
+                .header("Content-Type", MediaType.APPLICATION_FORM_URLENCODED_VALUE)
+                .header("Authorization", "Bearer " + accessToken)
+                .header(API.EXAM_API_SEB_CONNECTION_TOKEN, connectionToken)
+                .accept(MediaType.APPLICATION_OCTET_STREAM_VALUE);
+
+        final ResultActions result = this.mockMvc
+                .perform(builder)
+                .andDo(MvcResult::getAsyncResult);
+
+        return result.andReturn().getResponse();
+    }
+
     @Autowired
     AdminAPIClientDetails adminClientDetails;
     @Autowired

src/test/java/ch/ethz/seb/sebserver/webservice/integration/api/exam/SebConnectionTest.java

@@ -0,0 +1,624 @@
+/*
+ * Copyright (c) 2019 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.webservice.integration.api.exam;
+
+import static org.junit.Assert.*;
+
+import java.util.Collection;
+import java.util.List;
+
+import org.junit.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.cache.Cache;
+import org.springframework.cache.Cache.ValueWrapper;
+import org.springframework.http.HttpStatus;
+import org.springframework.mock.web.MockHttpServletResponse;
+import org.springframework.test.context.jdbc.Sql;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import ch.ethz.seb.sebserver.gbl.api.API;
+import ch.ethz.seb.sebserver.gbl.api.APIMessage;
+import ch.ethz.seb.sebserver.gbl.api.APIMessage.ErrorMessage;
+import ch.ethz.seb.sebserver.gbl.api.JSONMapper;
+import ch.ethz.seb.sebserver.gbl.model.exam.Indicator.IndicatorType;
+import ch.ethz.seb.sebserver.gbl.model.session.IndicatorValue;
+import ch.ethz.seb.sebserver.webservice.datalayer.batis.mapper.ClientConnectionRecordMapper;
+import ch.ethz.seb.sebserver.webservice.datalayer.batis.mapper.ClientEventRecordMapper;
+import ch.ethz.seb.sebserver.webservice.datalayer.batis.model.ClientConnectionRecord;
+import ch.ethz.seb.sebserver.webservice.datalayer.batis.model.ClientEventRecord;
+import ch.ethz.seb.sebserver.webservice.servicelayer.session.impl.AbstractPingIndicator;
+import ch.ethz.seb.sebserver.webservice.servicelayer.session.impl.ClientConnectionDataInternal;
+import ch.ethz.seb.sebserver.webservice.servicelayer.session.impl.ExamSessionCacheService;
+
+@Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+public class SebConnectionTest extends ExamAPIIntegrationTester {
+
+    @Autowired
+    private ClientConnectionRecordMapper clientConnectionRecordMapper;
+    @Autowired
+    private ClientEventRecordMapper clientEventRecordMapper;
+    @Autowired
+    private JSONMapper jsonMapper;
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testCreateConnection() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, 1L, null);
+        assertNotNull(createConnection);
+
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == createConnection.getStatus());
+        final String contentAsString = createConnection.getContentAsString();
+        assertEquals("[{\"examId\":\"2\",\"name\":\"Demo Quiz 6\",\"url\":\"http://lms.mockup.com/api/\"}]",
+                contentAsString);
+
+        // check connection token
+        final String connectionToken = createConnection.getHeader(API.EXAM_API_SEB_CONNECTION_TOKEN);
+        assertNotNull(connectionToken);
+
+        // check correct stored
+        final List<ClientConnectionRecord> records = this.clientConnectionRecordMapper
+                .selectByExample()
+                .build()
+                .execute();
+
+        assertTrue(records.size() == 1);
+        final ClientConnectionRecord clientConnectionRecord = records.get(0);
+        assertEquals("1", String.valueOf(clientConnectionRecord.getInstitutionId()));
+        assertNull(clientConnectionRecord.getExamId());
+        assertEquals("CONNECTION_REQUESTED", String.valueOf(clientConnectionRecord.getStatus()));
+        assertEquals(connectionToken, clientConnectionRecord.getConnectionToken());
+        assertNotNull(clientConnectionRecord.getClientAddress());
+        assertNull(clientConnectionRecord.getExamUserSessionIdentifer());
+        assertNull(clientConnectionRecord.getVirtualClientAddress());
+
+        // check caching
+        final Cache examCache = this.cacheManager
+                .getCache(ExamSessionCacheService.CACHE_NAME_RUNNING_EXAM);
+        final ValueWrapper exam = examCache.get(2L);
+        assertNotNull(exam);
+
+        final Cache connectionCache = this.cacheManager
+                .getCache(ExamSessionCacheService.CACHE_NAME_ACTIVE_CLIENT_CONNECTION);
+        final ValueWrapper connection = connectionCache.get(connectionToken);
+        assertNotNull(connection);
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testCreateConnectionWithExamId() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, 1L, 2L);
+        assertNotNull(createConnection);
+
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == createConnection.getStatus());
+        final String contentAsString = createConnection.getContentAsString();
+        assertEquals("[{\"examId\":\"2\",\"name\":\"Demo Quiz 6\",\"url\":\"http://lms.mockup.com/api/\"}]",
+                contentAsString);
+
+        // check connection token
+        final String connectionToken = createConnection.getHeader(API.EXAM_API_SEB_CONNECTION_TOKEN);
+        assertNotNull(connectionToken);
+
+        // check correct stored
+        final List<ClientConnectionRecord> records = this.clientConnectionRecordMapper
+                .selectByExample()
+                .build()
+                .execute();
+
+        assertTrue(records.size() == 1);
+        final ClientConnectionRecord clientConnectionRecord = records.get(0);
+        assertEquals("1", String.valueOf(clientConnectionRecord.getInstitutionId()));
+        assertEquals("2", String.valueOf(clientConnectionRecord.getExamId()));
+        assertEquals("CONNECTION_REQUESTED", String.valueOf(clientConnectionRecord.getStatus()));
+        assertEquals(connectionToken, clientConnectionRecord.getConnectionToken());
+        assertNotNull(clientConnectionRecord.getClientAddress());
+        assertNull(clientConnectionRecord.getExamUserSessionIdentifer());
+        assertNull(clientConnectionRecord.getVirtualClientAddress());
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testCreateConnectionWithWrongExamId() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, 1L, 1L);
+        assertNotNull(createConnection);
+
+        // expecting error status
+        assertTrue(createConnection.getStatus() != HttpStatus.OK.value());
+        final String contentAsString = createConnection.getContentAsString();
+        final Collection<APIMessage> errorMessage = this.jsonMapper.readValue(
+                contentAsString,
+                new TypeReference<Collection<APIMessage>>() {
+                });
+        final APIMessage error = errorMessage.iterator().next();
+        assertEquals(ErrorMessage.UNEXPECTED.messageCode, error.messageCode);
+        assertEquals("The exam 1 is not running", error.details);
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testCreateConnectionNoInstitutionId() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, null, null);
+        assertNotNull(createConnection);
+
+        // expecting error status
+        assertTrue(createConnection.getStatus() != HttpStatus.OK.value());
+        final String contentAsString = createConnection.getContentAsString();
+        final Collection<APIMessage> errorMessage = this.jsonMapper.readValue(
+                contentAsString,
+                new TypeReference<Collection<APIMessage>>() {
+                });
+        final APIMessage error = errorMessage.iterator().next();
+        assertEquals(ErrorMessage.GENERIC.messageCode, error.messageCode);
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testUpdateConnection() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, 1L, null);
+        assertNotNull(createConnection);
+
+        final String connectionToken = createConnection.getHeader(API.EXAM_API_SEB_CONNECTION_TOKEN);
+        assertNotNull(connectionToken);
+
+        // check cache after creation
+        Cache connectionCache = this.cacheManager
+                .getCache(ExamSessionCacheService.CACHE_NAME_ACTIVE_CLIENT_CONNECTION);
+        ClientConnectionDataInternal ccdi =
+                (ClientConnectionDataInternal) connectionCache.get(connectionToken).get();
+        assertNotNull(ccdi);
+        assertNull(ccdi.clientConnection.examId);
+        assertTrue(ccdi.indicatorValues.isEmpty());
+
+        final MockHttpServletResponse updatedConnection = super.updateConnection(
+                accessToken,
+                connectionToken,
+                2L,
+                "userSessionId");
+
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == updatedConnection.getStatus());
+
+        // check correct stored
+        final List<ClientConnectionRecord> records = this.clientConnectionRecordMapper
+                .selectByExample()
+                .build()
+                .execute();
+
+        assertTrue(records.size() == 1);
+        final ClientConnectionRecord clientConnectionRecord = records.get(0);
+        assertEquals("1", String.valueOf(clientConnectionRecord.getInstitutionId()));
+        assertEquals("2", String.valueOf(clientConnectionRecord.getExamId()));
+        assertEquals("CONNECTION_REQUESTED", String.valueOf(clientConnectionRecord.getStatus()));
+        assertNotNull(clientConnectionRecord.getConnectionToken());
+        assertNotNull(clientConnectionRecord.getClientAddress());
+        assertEquals("userSessionId", clientConnectionRecord.getExamUserSessionIdentifer());
+        assertNull(clientConnectionRecord.getVirtualClientAddress());
+
+        // check cache after update
+        connectionCache = this.cacheManager
+                .getCache(ExamSessionCacheService.CACHE_NAME_ACTIVE_CLIENT_CONNECTION);
+        ccdi =
+                (ClientConnectionDataInternal) connectionCache.get(connectionToken).get();
+        assertNotNull(ccdi);
+        assertNotNull(ccdi.clientConnection.examId);
+        assertFalse(ccdi.indicatorValues.isEmpty());
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testUpdateConnectionWithWrongConnectionToken() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse updatedConnection = super.updateConnection(
+                accessToken,
+                "",
+                2L,
+                "userSessionId");
+
+        // expecting error status
+        assertTrue(HttpStatus.OK.value() != updatedConnection.getStatus());
+        final String contentAsString = updatedConnection.getContentAsString();
+        final Collection<APIMessage> errorMessage = this.jsonMapper.readValue(
+                contentAsString,
+                new TypeReference<Collection<APIMessage>>() {
+                });
+        final APIMessage error = errorMessage.iterator().next();
+        assertEquals(ErrorMessage.RESOURCE_NOT_FOUND.messageCode, error.messageCode);
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testEstablishConnection() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, 1L, null);
+        assertNotNull(createConnection);
+
+        final String connectionToken = createConnection.getHeader(API.EXAM_API_SEB_CONNECTION_TOKEN);
+        assertNotNull(connectionToken);
+
+        // check cache after creation
+        final Cache connectionCache = this.cacheManager
+                .getCache(ExamSessionCacheService.CACHE_NAME_ACTIVE_CLIENT_CONNECTION);
+        ClientConnectionDataInternal ccdi =
+                (ClientConnectionDataInternal) connectionCache.get(connectionToken).get();
+        assertNotNull(ccdi);
+        assertNull(ccdi.clientConnection.examId);
+        assertTrue(ccdi.indicatorValues.isEmpty());
+
+        final MockHttpServletResponse updatedConnection = super.establishConnection(
+                accessToken,
+                connectionToken,
+                2L,
+                "userSessionId");
+
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == updatedConnection.getStatus());
+
+        // check correct stored
+        final List<ClientConnectionRecord> records = this.clientConnectionRecordMapper
+                .selectByExample()
+                .build()
+                .execute();
+
+        assertTrue(records.size() == 1);
+        final ClientConnectionRecord clientConnectionRecord = records.get(0);
+        assertEquals("1", String.valueOf(clientConnectionRecord.getInstitutionId()));
+        assertEquals("2", String.valueOf(clientConnectionRecord.getExamId()));
+        assertEquals("ESTABLISHED", String.valueOf(clientConnectionRecord.getStatus()));
+        assertNotNull(clientConnectionRecord.getConnectionToken());
+        assertNotNull(clientConnectionRecord.getClientAddress());
+        assertEquals("userSessionId", clientConnectionRecord.getExamUserSessionIdentifer());
+        assertNull(clientConnectionRecord.getVirtualClientAddress());
+
+        // check cache after update
+        ccdi = (ClientConnectionDataInternal) connectionCache.get(connectionToken).get();
+        assertNotNull(ccdi);
+        assertNotNull(ccdi.clientConnection.examId);
+        assertFalse(ccdi.indicatorValues.isEmpty());
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testEstablishConnectionNoExamLeadsToError() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, 1L, null);
+        assertNotNull(createConnection);
+
+        final String connectionToken = createConnection.getHeader(API.EXAM_API_SEB_CONNECTION_TOKEN);
+        assertNotNull(connectionToken);
+
+        // check cache after creation
+        final Cache connectionCache = this.cacheManager
+                .getCache(ExamSessionCacheService.CACHE_NAME_ACTIVE_CLIENT_CONNECTION);
+        ClientConnectionDataInternal ccdi =
+                (ClientConnectionDataInternal) connectionCache.get(connectionToken).get();
+        assertNotNull(ccdi);
+        assertNull(ccdi.clientConnection.examId);
+        assertTrue(ccdi.indicatorValues.isEmpty());
+
+        final MockHttpServletResponse updatedConnection = super.establishConnection(
+                accessToken,
+                connectionToken,
+                null,
+                null);
+
+        // check correct response
+        assertTrue(HttpStatus.OK.value() != updatedConnection.getStatus());
+        final String contentAsString = updatedConnection.getContentAsString();
+        final Collection<APIMessage> errorMessage = this.jsonMapper.readValue(
+                contentAsString,
+                new TypeReference<Collection<APIMessage>>() {
+                });
+        final APIMessage error = errorMessage.iterator().next();
+        assertEquals(ErrorMessage.UNEXPECTED.messageCode, error.messageCode);
+        assertEquals("ClientConnection integrity violation", error.details);
+
+        // check correct stored (no changes)
+        final List<ClientConnectionRecord> records = this.clientConnectionRecordMapper
+                .selectByExample()
+                .build()
+                .execute();
+
+        assertTrue(records.size() == 1);
+        final ClientConnectionRecord clientConnectionRecord = records.get(0);
+        assertEquals("1", String.valueOf(clientConnectionRecord.getInstitutionId()));
+        assertNull(clientConnectionRecord.getExamId());
+        assertEquals("CONNECTION_REQUESTED", String.valueOf(clientConnectionRecord.getStatus()));
+        assertNotNull(clientConnectionRecord.getConnectionToken());
+        assertNotNull(clientConnectionRecord.getClientAddress());
+        assertNull(clientConnectionRecord.getExamUserSessionIdentifer());
+        assertNull(clientConnectionRecord.getVirtualClientAddress());
+
+        // check cache fail remains the same
+        ccdi = (ClientConnectionDataInternal) connectionCache.get(connectionToken).get();
+        assertNotNull(ccdi);
+        assertNull(ccdi.clientConnection.examId);
+        assertTrue(ccdi.indicatorValues.isEmpty());
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testCloseConnection() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, 1L, null);
+        assertNotNull(createConnection);
+
+        final String connectionToken = createConnection.getHeader(API.EXAM_API_SEB_CONNECTION_TOKEN);
+        assertNotNull(connectionToken);
+
+        final MockHttpServletResponse establishConnection = super.establishConnection(
+                accessToken,
+                connectionToken,
+                2L,
+                null);
+
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == establishConnection.getStatus());
+
+        // check cache after creation
+        final Cache connectionCache = this.cacheManager
+                .getCache(ExamSessionCacheService.CACHE_NAME_ACTIVE_CLIENT_CONNECTION);
+        ClientConnectionDataInternal ccdi =
+                (ClientConnectionDataInternal) connectionCache.get(connectionToken).get();
+        assertNotNull(ccdi);
+        assertNotNull(ccdi.clientConnection.examId);
+        assertFalse(ccdi.indicatorValues.isEmpty());
+
+        // close connection
+        final MockHttpServletResponse closedConnection = super.closeConnection(
+                accessToken,
+                connectionToken);
+
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == closedConnection.getStatus());
+
+        // check correct stored (no changes)
+        final List<ClientConnectionRecord> records = this.clientConnectionRecordMapper
+                .selectByExample()
+                .build()
+                .execute();
+
+        assertTrue(records.size() == 1);
+        final ClientConnectionRecord clientConnectionRecord = records.get(0);
+        assertEquals("1", String.valueOf(clientConnectionRecord.getInstitutionId()));
+        assertEquals("2", String.valueOf(clientConnectionRecord.getExamId()));
+        assertEquals("CLOSED", String.valueOf(clientConnectionRecord.getStatus()));
+        assertNotNull(clientConnectionRecord.getConnectionToken());
+        assertNotNull(clientConnectionRecord.getClientAddress());
+        assertNull(clientConnectionRecord.getExamUserSessionIdentifer());
+        assertNull(clientConnectionRecord.getVirtualClientAddress());
+
+        // check cache after update
+        ccdi = (ClientConnectionDataInternal) connectionCache.get(connectionToken).get();
+        assertNotNull(ccdi);
+        assertNotNull(ccdi.clientConnection.examId);
+        assertFalse(ccdi.indicatorValues.isEmpty());
+        assertEquals("CLOSED", ccdi.clientConnection.status.toString());
+
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testPing() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, 1L, null);
+        assertNotNull(createConnection);
+
+        final String connectionToken = createConnection.getHeader(API.EXAM_API_SEB_CONNECTION_TOKEN);
+        assertNotNull(connectionToken);
+
+        final MockHttpServletResponse establishConnection = super.establishConnection(
+                accessToken,
+                connectionToken,
+                2L,
+                null);
+
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == establishConnection.getStatus());
+
+        final Cache connectionCache = this.cacheManager
+                .getCache(ExamSessionCacheService.CACHE_NAME_ACTIVE_CLIENT_CONNECTION);
+        final ClientConnectionDataInternal ccdi =
+                (ClientConnectionDataInternal) connectionCache.get(connectionToken).get();
+        assertNotNull(ccdi);
+        assertNotNull(ccdi.clientConnection.examId);
+        assertFalse(ccdi.indicatorValues.isEmpty());
+        final IndicatorValue pingIndicator = ccdi.indicatorValues.iterator().next();
+        assertTrue(pingIndicator.getType() == IndicatorType.LAST_PING);
+        assertEquals("0", String.valueOf(((AbstractPingIndicator) pingIndicator).getPingNumber()));
+
+        super.sendPing(accessToken, connectionToken, 1);
+        assertEquals("1", String.valueOf(((AbstractPingIndicator) pingIndicator).getPingNumber()));
+        super.sendPing(accessToken, connectionToken, 2);
+        assertEquals("2", String.valueOf(((AbstractPingIndicator) pingIndicator).getPingNumber()));
+        super.sendPing(accessToken, connectionToken, 3);
+        assertEquals("3", String.valueOf(((AbstractPingIndicator) pingIndicator).getPingNumber()));
+        super.sendPing(accessToken, connectionToken, 5);
+        assertEquals("5", String.valueOf(((AbstractPingIndicator) pingIndicator).getPingNumber()));
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testSendPingToNoneEstablishedConnectionIsIgnored() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, 1L, null);
+        assertNotNull(createConnection);
+
+        final String connectionToken = createConnection.getHeader(API.EXAM_API_SEB_CONNECTION_TOKEN);
+        assertNotNull(connectionToken);
+
+        final MockHttpServletResponse sendPing = super.sendPing(accessToken, connectionToken, 1);
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == sendPing.getStatus());
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testEvent() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, 1L, null);
+        assertNotNull(createConnection);
+
+        final String connectionToken = createConnection.getHeader(API.EXAM_API_SEB_CONNECTION_TOKEN);
+        assertNotNull(connectionToken);
+
+        final MockHttpServletResponse establishConnection = super.establishConnection(
+                accessToken,
+                connectionToken,
+                2L,
+                null);
+
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == establishConnection.getStatus());
+
+        final Cache connectionCache = this.cacheManager
+                .getCache(ExamSessionCacheService.CACHE_NAME_ACTIVE_CLIENT_CONNECTION);
+        final ClientConnectionDataInternal ccdi =
+                (ClientConnectionDataInternal) connectionCache.get(connectionToken).get();
+        assertNotNull(ccdi);
+        assertNotNull(ccdi.clientConnection.examId);
+        assertFalse(ccdi.indicatorValues.isEmpty());
+        final IndicatorValue pingIndicator = ccdi.indicatorValues.iterator().next();
+        assertTrue(pingIndicator.getType() == IndicatorType.LAST_PING);
+        assertEquals("0", String.valueOf(((AbstractPingIndicator) pingIndicator).getPingNumber()));
+
+        MockHttpServletResponse sendEvent = super.sendEvent(
+                accessToken,
+                connectionToken,
+                "INFO_LOG",
+                1l,
+                100.0,
+                "testEvent1");
+
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == sendEvent.getStatus());
+
+        // check event stored on db
+        List<ClientEventRecord> events = this.clientEventRecordMapper
+                .selectByExample()
+                .build()
+                .execute();
+
+        assertFalse(events.isEmpty());
+        final ClientEventRecord clientEventRecord = events.get(0);
+        assertEquals(
+                "ClientEventRecord ["
+                        + "Hash = -1088444763, "
+                        + "id=1, "
+                        + "connectionId=1, "
+                        + "type=2, "
+                        + "timestamp=1, "
+                        + "numericValue=100.0000, "
+                        + "text=testEvent1]",
+                clientEventRecord.toString());
+
+        // send another event
+        sendEvent = super.sendEvent(
+                accessToken,
+                connectionToken,
+                "ERROR_LOG",
+                2l,
+                10000.0,
+                "testEvent2");
+
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == sendEvent.getStatus());
+
+        // check event stored on db
+        events = this.clientEventRecordMapper
+                .selectByExample()
+                .build()
+                .execute();
+
+        assertFalse(events.isEmpty());
+        assertTrue(events.stream().filter(ev -> ev.getTimestamp().equals(2l)).findFirst().isPresent());
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testSendEventToNoneEstablishedConnectionLeadsToError() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse createConnection = super.createConnection(accessToken, 1L, null);
+        assertNotNull(createConnection);
+
+        final String connectionToken = createConnection.getHeader(API.EXAM_API_SEB_CONNECTION_TOKEN);
+        assertNotNull(connectionToken);
+
+        final MockHttpServletResponse sendEvent = super.sendEvent(
+                accessToken,
+                connectionToken,
+                "INFO_LOG",
+                1l,
+                100.0,
+                "testEvent1");
+        // check correct response
+        assertTrue(HttpStatus.OK.value() != sendEvent.getStatus());
+
+        final List<ClientEventRecord> events = this.clientEventRecordMapper
+                .selectByExample()
+                .build()
+                .execute();
+        assertTrue(events.isEmpty());
+    }
+
+    @Test
+    @Sql(scripts = { "classpath:schema-test.sql", "classpath:data-test.sql", "classpath:data-test-additional.sql" })
+    public void testSendEventToNoneExistingConnectionIsIgnored() throws Exception {
+        final String accessToken = super.obtainAccessToken("test", "test", "SEBClient");
+        assertNotNull(accessToken);
+
+        final MockHttpServletResponse sendEvent = super.sendEvent(
+                accessToken,
+                "someInvalidConnectionToken",
+                "INFO_LOG",
+                1l,
+                100.0,
+                "testEvent1");
+        // check correct response
+        assertTrue(HttpStatus.OK.value() == sendEvent.getStatus());
+
+        final List<ClientEventRecord> events = this.clientEventRecordMapper
+                .selectByExample()
+                .build()
+                .execute();
+        assertTrue(events.isEmpty());
+    }
+}

src/test/resources/application-test.properties

@@ -21,7 +21,6 @@ sebserver.webservice.api.exam.endpoint.discovery=${sebserver.webservice.api.exam
 sebserver.webservice.api.exam.endpoint.v1=${sebserver.webservice.api.exam.endpoint}/v1
 sebserver.webservice.api.exam.accessTokenValiditySeconds=1800
 sebserver.webservice.api.exam.refreshTokenValiditySeconds=-1
-sebserver.webservice.internalSecret=TO_SET
 sebserver.webservice.api.redirect.unauthorized=none
 # comma separated list of known possible OpenEdX API access token request endpoints
 sebserver.webservice.lms.openedx.api.token.request.paths=/oauth2/access_token