- Add check for remaining "bulkImportDirsUnderProcessing", before shutting down the Service.

- Code polishing.

src/main/java/eu/openaire/urls_controller/components/ScheduledTasks.java

@@ -4,6 +4,7 @@ import com.google.gson.Gson;
 import com.google.gson.JsonSyntaxException;
 import eu.openaire.urls_controller.Application;
 import eu.openaire.urls_controller.configuration.DatabaseConnector;
+import eu.openaire.urls_controller.controllers.BulkImportController;
 import eu.openaire.urls_controller.controllers.ShutdownController;
 import eu.openaire.urls_controller.controllers.StatsController;
 import eu.openaire.urls_controller.controllers.UrlsController;
@@ -69,7 +70,6 @@ public class ScheduledTasks {
     {
         if ( !workerReportsDirPath.endsWith("/") )
             workerReportsDirPath += "/";
-
         this.workerReportsDirPath = workerReportsDirPath;   // This dir will be created later.
         this.statsController = statsController;
         this.urlsController = urlsController;
@@ -89,9 +89,9 @@ public class ScheduledTasks {
     // The initial delay is larger, because we have to wait some time for at least one worker to finish retrieving the full-texts from thousands of publications, whereas, later we will have a lot of workerReports waiting to be processed.
     public void executeBackgroundTasks()
     {
-        List<Callable<Boolean>> tempList = new ArrayList<>(UrlsController.backgroundCallableTasks);   // Copy the list in order to know what was executed.
+        List<Callable<Boolean>> tempList = new ArrayList<>(UrlsController.backgroundCallableTasks);   // Deep-copy the list in order to know what was executed.
         // So the items added while this execution happens, will remain in the global-list, while the others will have already been deleted.
-        // Also, the "Executor.invokeAll()" requires an "unchanged" list, otherwise there will be "undefined results".
+        // Also, the "Executor.invokeAll()" requires an "unchanged" list, hence the "tempList", otherwise there will be "undefined results".
         int numOfTasks = tempList.size();   // Since the temp-list is a deep-copy and not a reference, new tasks that are added will not be executed.
         if ( numOfTasks == 0 )
             return;
@@ -105,15 +105,15 @@ public class ScheduledTasks {
         try {
             List<Future<Boolean>> futures = UrlsController.backgroundExecutor.invokeAll(tempList);
             int sizeOfFutures = futures.size();
-            for ( int i = 0; i < sizeOfFutures; ++i ) {
+            for ( int i=0; i < sizeOfFutures; ++i ) {
                 try {
                     Boolean value = futures.get(i).get();	// Get and see if an exception is thrown..
                     // Add check for the value, if wanted.. (we don't care at the moment)
                 } catch (ExecutionException ee) {
                     String stackTraceMessage = GenericUtils.getSelectiveStackTrace(ee, null, 15);	// These can be serious errors like an "out of memory exception" (Java HEAP).
-                    logger.error("Task_" + (i+1) + " failed with: " + ee.getMessage() + GenericUtils.endOfLine + stackTraceMessage);
+                    logger.error("Task_" + i + " failed with: " + ee.getMessage() + GenericUtils.endOfLine + stackTraceMessage);
                 } catch (CancellationException ce) {
-                    logger.error("Task_" + (i+1) + " was cancelled: " + ce.getMessage());
+                    logger.error("Task_" + i + " was cancelled: " + ce.getMessage());
                 } catch (IndexOutOfBoundsException ioobe) {
                     logger.error("IOOBE for task_" + i + " in the futures-list! " + ioobe.getMessage());
                 }
@@ -135,6 +135,11 @@ public class ScheduledTasks {
         if ( UrlsController.backgroundCallableTasks.size() > 0 )
             return;
 
+        // Check whether there are any active bulk-import procedures.
+        if ( BulkImportController.bulkImportDirsUnderProcessing.size() > 0 )
+            return;
+
+        // Check whether the workers have not shutdown yet, which means that they either crawl assignments or/and they are waiting for the Controller to process the WorkerReport and then shutdown.
         Set<String> workerIds = UrlsController.workersInfoMap.keySet();
         if ( workerIds.size() > 0 ) {
             for ( String workerId : workerIds )