From c05ea841bce27995166689e1db22ea1f027f809c Mon Sep 17 00:00:00 2001
From: Juergen Hoeller <juergen.hoeller@broadcom.com>
Date: Wed, 21 Jan 2026 19:45:18 +0100
Subject: [PATCH] Declare Callable parameter with nullable type variable

Closes gh-36191
---
 .../org/springframework/core/task/AsyncTaskExecutor.java    | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/spring-core/src/main/java/org/springframework/core/task/AsyncTaskExecutor.java b/spring-core/src/main/java/org/springframework/core/task/AsyncTaskExecutor.java
index c1407849ef9..2ad95139c07 100644
--- a/spring-core/src/main/java/org/springframework/core/task/AsyncTaskExecutor.java
+++ b/spring-core/src/main/java/org/springframework/core/task/AsyncTaskExecutor.java
@@ -21,6 +21,8 @@ import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Future;
 import java.util.concurrent.FutureTask;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.concurrent.FutureUtils;
 
 /**
@@ -105,7 +107,7 @@ public interface AsyncTaskExecutor extends TaskExecutor {
 	 * @throws TaskRejectedException if the given task was not accepted
 	 * @since 3.0
 	 */
-	default <T> Future<T> submit(Callable<T> task) {
+	default <T extends @Nullable Object> Future<T> submit(Callable<T> task) {
 		FutureTask<T> future = new FutureTask<>(task);
 		execute(future, TIMEOUT_INDEFINITE);
 		return future;
@@ -132,7 +134,7 @@ public interface AsyncTaskExecutor extends TaskExecutor {
 	 * @throws TaskRejectedException if the given task was not accepted
 	 * @since 6.0
 	 */
-	default <T> CompletableFuture<T> submitCompletable(Callable<T> task) {
+	default <T extends @Nullable Object> CompletableFuture<T> submitCompletable(Callable<T> task) {
 		return FutureUtils.callAsync(task, this);
 	}