Use whenComplete since (null) return value not needed

Author: kazuki-ma

spring-core/src/main/java/org/springframework/util/concurrent/CompletableToListenableFutureAdapter.java

@@ -21,6 +21,7 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
+import java.util.function.BiConsumer;
 
 /**
  * Adapts a {@link CompletableFuture} or {@link CompletionStage} into a
@@ -50,14 +51,13 @@ public CompletableToListenableFutureAdapter(CompletionStage<T> completionStage)
 	 */
 	public CompletableToListenableFutureAdapter(CompletableFuture<T> completableFuture) {
 		this.completableFuture = completableFuture;
-		this.completableFuture.handle((result, ex) -> {
+		this.completableFuture.whenComplete((result, ex) -> {
 			if (ex != null) {
 				callbacks.failure(ex);
 			}
 			else {
 				callbacks.success(result);
 			}
-			return null;
 		});
 	}