Interrupt all running tasks during shutdown

CHANGELOG.md

@@ -19,6 +19,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 
 ### Fixed
 
+- We fixed an issue where the `.sav` file was not deleted upon exiting JabRef. [#6109](https://github.com/JabRef/jabref/issues/6109)
 - We fixed an issue where opening a library from the recent libraries menu was not possible. [#5939](https://github.com/JabRef/jabref/issues/5939)
 
 ### Removed

src/main/java/org/jabref/logic/util/DelayTaskThrottler.java

@@ -32,6 +32,7 @@ public DelayTaskThrottler(int delay) {
         this.delay = delay;
         this.executor = new ScheduledThreadPoolExecutor(1);
         this.executor.setRemoveOnCancelPolicy(true);
+        this.executor.setExecuteExistingDelayedTasksAfterShutdownPolicy(false);
     }
 
     public void schedule(Runnable command) {
@@ -47,5 +48,19 @@ public void schedule(Runnable command) {
 
     public void shutdown() {
         executor.shutdown();
+        try {
+            if (!executor.awaitTermination(60, TimeUnit.SECONDS)) {
+                LOGGER.debug("One minute passed, saving still not completed. Trying forced shutdown.");
+                executor.shutdownNow();
+                if (executor.awaitTermination(60, TimeUnit.SECONDS)) {
+                    LOGGER.debug("One minute passed again - forced shutdown worked.");
+                } else {
+                    LOGGER.error("DelayedTaskThrottler did not terminate");
+                }
+            }
+        } catch (InterruptedException ie) {
+            executor.shutdownNow();
+            Thread.currentThread().interrupt();
+        }
     }
 }