Wait to ask to collect anonymous statistics in JabRefExecutorService …

…to allow jvm to terminate (JabRef#3266)

* use JabRefExecutorService for TrackingNotification instead of a new ExecutorService

* add changelog entry

CHANGELOG.md

@@ -16,6 +16,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 - We added support for '[entrytype]' bracketed expression.
 
 ### Fixed
+ - We fixed an issue where JabRef would not terminated after asking to collect anonymous statistics [#2955 comment](https://github.com/JabRef/jabref/issues/2955#issuecomment-334591123)
 
 ### Removed
 

src/main/java/org/jabref/gui/JabRefFrame.java

@@ -30,9 +30,7 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
+import java.util.TimerTask;
 
 import javax.swing.AbstractAction;
 import javax.swing.Action;
@@ -64,6 +62,7 @@
 import javafx.application.Platform;
 
 import org.jabref.Globals;
+import org.jabref.JabRefExecutorService;
 import org.jabref.gui.actions.Actions;
 import org.jabref.gui.actions.AutoLinkFilesAction;
 import org.jabref.gui.actions.ConnectToSharedDatabaseAction;
@@ -661,8 +660,13 @@ public void windowClosing(WindowEvent e) {
 
     private void initShowTrackingNotification() {
         if (!Globals.prefs.shouldAskToCollectTelemetry()) {
-            ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
-            scheduler.schedule(() -> DefaultTaskExecutor.runInJavaFXThread(this::showTrackingNotification), 1, TimeUnit.MINUTES);
+            JabRefExecutorService.INSTANCE.submit(new TimerTask() {
+
+                @Override
+                public void run() {
+                    DefaultTaskExecutor.runInJavaFXThread(JabRefFrame.this::showTrackingNotification);
+                }
+            }, 60000); // run in one minute
         }
     }