From 34bcd7d60c39a97aa6b86da8779a93dccee5ab44 Mon Sep 17 00:00:00 2001
From: Gary Russell <grussell@pivotal.io>
Date: Tue, 30 Apr 2019 14:04:50 -0400
Subject: [PATCH] Synchronize RemoteFileUtils.makeDirectories()

https://stackoverflow.com/questions/55918648

Avoid the race with concurrent threads.

**cherry-pick to 5.x.x, 4.3.x**

(cherry picked from commit 130e1bba3163ae79fbd82d36910574606738b011)
---
 .../integration/file/remote/RemoteFileUtils.java          | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/spring-integration-file/src/main/java/org/springframework/integration/file/remote/RemoteFileUtils.java b/spring-integration-file/src/main/java/org/springframework/integration/file/remote/RemoteFileUtils.java
index ae327afd7c..9147d9d527 100644
--- a/spring-integration-file/src/main/java/org/springframework/integration/file/remote/RemoteFileUtils.java
+++ b/spring-integration-file/src/main/java/org/springframework/integration/file/remote/RemoteFileUtils.java
@@ -32,7 +32,9 @@ import org.springframework.integration.file.remote.session.Session;
  */
 public final class RemoteFileUtils {
 
-	private RemoteFileUtils() { }
+	private RemoteFileUtils() {
+		super();
+	}
 
 	/**
 	 * Recursively create remote directories.
@@ -43,8 +45,8 @@ public final class RemoteFileUtils {
 	 * @param logger The logger.
 	 * @throws IOException Any IOException.
 	 */
-	public static <F> void makeDirectories(String path, Session<F> session, String remoteFileSeparator, Log logger)
-			throws IOException {
+	public static synchronized <F> void makeDirectories(String path, Session<F> session, String remoteFileSeparator,
+			Log logger) throws IOException {
 
 		if (!session.exists(path)) {