Start version 2.5

* Upgrade some dependencies; fix compatibilities

src/main/java/org/springframework/integration/aws/support/filters/S3PersistentAcceptOnceFileListFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2019 the original author or authors.
+ * Copyright 2016-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -43,4 +43,15 @@ public class S3PersistentAcceptOnceFileListFilter extends AbstractPersistentAcce
 		return (file != null) ? file.getKey() : null;
 	}
 
+	/**
+	 * Always return false since no directory notion in S3.
+	 * @param file the {@link S3ObjectSummary}
+	 * @return always false: S3 does not have a notion of directory
+	 * @since 2.5
+	 */
+	@Override
+	protected boolean isDirectory(S3ObjectSummary file) {
+		return false;
+	}
+
 }