diff -r 63a31871189e -r fd8c40ff78c3 src/main/java/de/uapcore/lightpit/DatabaseFacade.java
--- a/src/main/java/de/uapcore/lightpit/DatabaseFacade.java	Sat May 09 14:58:41 2020 +0200
+++ b/src/main/java/de/uapcore/lightpit/DatabaseFacade.java	Sat May 09 15:19:21 2020 +0200
@@ -28,10 +28,9 @@
  */
 package de.uapcore.lightpit;
 
-import java.sql.Connection;
-import java.sql.DatabaseMetaData;
-import java.sql.SQLException;
-import java.util.Optional;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import javax.naming.Context;
 import javax.naming.InitialContext;
 import javax.naming.NamingException;
@@ -40,31 +39,33 @@
 import javax.servlet.ServletContextListener;
 import javax.servlet.annotation.WebListener;
 import javax.sql.DataSource;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.SQLException;
+import java.util.Optional;
 
 /**
  * Provides access to different privilege layers within the database.
  */
 @WebListener
 public final class DatabaseFacade implements ServletContextListener {
-    
+
     private static final Logger LOG = LoggerFactory.getLogger(DatabaseFacade.class);
-    
+
     /**
      * Timeout in seconds for the validation test.
      */
     private static final int DB_TEST_TIMEOUT = 10;
-    
-    public static enum Dialect {
-        Postgres;
+
+    public enum Dialect {
+        Postgres
     }
-    
+
     /**
      * The database dialect to use.
-     * 
+     * <p>
      * May be override by context parameter.
-     * 
+     *
      * @see Constants#CTX_ATTR_DB_DIALECT
      */
     private Dialect dialect = Dialect.Postgres;
@@ -82,10 +83,9 @@
      * The attribute name in the Servlet context under which an instance of this class can be found.
      */
     public static final String SC_ATTR_NAME = DatabaseFacade.class.getName();
-    private ServletContext sc;
-    
+
     private static final String DS_JNDI_NAME = "jdbc/lightpit/app";
-    private Optional<DataSource> dataSource;
+    private DataSource dataSource;
     
     /**
      * Returns the data source.
@@ -97,14 +97,15 @@
      * @return a data source
      */
     public Optional<DataSource> getDataSource() {
-        return dataSource;
+        // TODO: this should not be an optional, if an empty optional is actually an exception
+        return Optional.ofNullable(dataSource);
     }
     
     public Dialect getSQLDialect() {
         return dialect;
     }
-    
-    private static void checkConnection(DataSource ds, String testSchema, String errMsg) {
+
+    private static void checkConnection(DataSource ds, String testSchema) {
         try (Connection conn = ds.getConnection()) {
             if (!conn.isValid(DB_TEST_TIMEOUT)) {
                 throw new SQLException("Validation check failed.");
@@ -118,25 +119,25 @@
             DatabaseMetaData metaData = conn.getMetaData();
             LOG.info("Connections as {} to {}/{} ready to go.", metaData.getUserName(), metaData.getURL(), conn.getSchema());
         } catch (SQLException ex) {
-            LOG.error(errMsg, ex);
+            LOG.error("Checking database connection failed", ex);
         }
     }
-    
-    private static Optional<DataSource> retrieveDataSource(Context ctx) {
+
+    private static DataSource retrieveDataSource(Context ctx) {
         DataSource ret = null;
         try {
-            ret = (DataSource)ctx.lookup(DS_JNDI_NAME);
+            ret = (DataSource) ctx.lookup(DS_JNDI_NAME);
             LOG.info("Data source retrieved.");
         } catch (NamingException ex) {
             LOG.error("Data source {} not available.", DS_JNDI_NAME);
             LOG.error("Reason for the missing data source: ", ex);
         }
-        return Optional.ofNullable(ret);
+        return ret;
     }
 
     @Override
     public void contextInitialized(ServletContextEvent sce) {
-        sc = sce.getServletContext();
+        ServletContext sc = sce.getServletContext();
         
         dataSource = null;
         
@@ -159,10 +160,12 @@
             LOG.debug("Trying to access JNDI context {}...", contextName);
             Context initialCtx = new InitialContext();
             Context ctx = (Context) initialCtx.lookup(contextName);
-            
+
             dataSource = retrieveDataSource(ctx);
-            
-            dataSource.ifPresent((ds) -> checkConnection(ds, dbSchema, "Checking database connection failed"));
+
+            if (dataSource != null) {
+                checkConnection(dataSource, dbSchema);
+            }
         } catch (NamingException | ClassCastException ex) {
             LOG.error("Cannot access JNDI resources.", ex);
         }