Use CompletableFuture instead of deprecated ListenableFuture.

Closes #2669

Author: mp911de

src/main/asciidoc/repositories.adoc

@@ -873,13 +873,9 @@ Future<User> findByFirstname(String firstname);               <1>
 
 @Async
 CompletableFuture<User> findOneByFirstname(String firstname); <2>
-
-@Async
-ListenableFuture<User> findOneByLastname(String lastname);    <3>
 ----
 <1> Use `java.util.concurrent.Future` as the return type.
 <2> Use a Java 8 `java.util.concurrent.CompletableFuture` as the return type.
-<3> Use a `org.springframework.util.concurrent.ListenableFuture` as the return type.
 ====
 
 [[repositories.create-instances]]

src/main/asciidoc/repository-query-return-types-reference.adoc

@@ -30,7 +30,6 @@ Some store modules may define their own result wrapper types.
 |Vavr `Seq`, `List`, `Map`, `Set`|Vavr collection types. See <<repositories.collections-and-iterables.vavr>> for details.
 |`Future<T>`|A `Future`. Expects a method to be annotated with `@Async` and requires Spring's asynchronous method execution capability to be enabled.
 |`CompletableFuture<T>`|A Java 8 `CompletableFuture`. Expects a method to be annotated with `@Async` and requires Spring's asynchronous method execution capability to be enabled.
-|`ListenableFuture`|A `org.springframework.util.concurrent.ListenableFuture`. Expects a method to be annotated with `@Async` and requires Spring's asynchronous method execution capability to be enabled.
 |`Slice<T>`|A sized chunk of data with an indication of whether there is more data available. Requires a `Pageable` method parameter.
 |`Page<T>`|A `Slice` with additional information, such as the total number of results. Requires a `Pageable` method parameter.
 |`GeoResult<T>`|A result entry with additional information, such as the distance to a reference location.

src/main/java/org/springframework/data/repository/util/QueryExecutionConverters.java

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.repository.util;
 
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -45,7 +44,6 @@
 import org.springframework.data.util.StreamUtils;
 import org.springframework.data.util.Streamable;
 import org.springframework.data.util.TypeInformation;
-import org.springframework.lang.NonNull;
 import org.springframework.lang.Nullable;
 import org.springframework.scheduling.annotation.AsyncResult;
 import org.springframework.util.Assert;
@@ -92,7 +90,9 @@ public abstract class QueryExecutionConverters {
 		WRAPPER_TYPES.add(WrapperType.singleValue(Future.class));
 		UNWRAPPER_TYPES.add(WrapperType.singleValue(Future.class));
 		WRAPPER_TYPES.add(WrapperType.singleValue(ListenableFuture.class));
+		WRAPPER_TYPES.add(WrapperType.singleValue(CompletableFuture.class));
 		UNWRAPPER_TYPES.add(WrapperType.singleValue(ListenableFuture.class));
+		UNWRAPPER_TYPES.add(WrapperType.singleValue(CompletableFuture.class));
 
 		ALLOWED_PAGEABLE_TYPES.add(Slice.class);
 		ALLOWED_PAGEABLE_TYPES.add(Page.class);
@@ -102,9 +102,7 @@ public abstract class QueryExecutionConverters {
 
 		UNWRAPPERS.addAll(CustomCollections.getUnwrappers());
 
-		CustomCollections.getCustomTypes().stream()
-				.map(WrapperType::multiValue)
-				.forEach(WRAPPER_TYPES::add);
+		CustomCollections.getCustomTypes().stream().map(WrapperType::multiValue).forEach(WRAPPER_TYPES::add);
 
 		CustomCollections.getPaginationReturnTypes().forEach(ALLOWED_PAGEABLE_TYPES::add);
 
@@ -302,8 +300,7 @@ private static abstract class AbstractWrapperTypeConverter implements GenericCon
 			this.wrapperTypes = Collections.singleton(nullValue.getClass());
 		}
 
-		AbstractWrapperTypeConverter(Object nullValue,
-				Iterable<Class<?>> wrapperTypes) {
+		AbstractWrapperTypeConverter(Object nullValue, Iterable<Class<?>> wrapperTypes) {
 			this.nullValue = nullValue;
 			this.wrapperTypes = wrapperTypes;
 		}
@@ -345,13 +342,14 @@ public final Object convert(@Nullable Object source, TypeDescriptor sourceType,
 	 *
 	 * @author Oliver Gierke
 	 */
+	@Deprecated(since = "3.0")
 	private static class NullableWrapperToFutureConverter extends AbstractWrapperTypeConverter {
 
 		/**
 		 * Creates a new {@link NullableWrapperToFutureConverter} using the given {@link ConversionService}.
 		 */
 		NullableWrapperToFutureConverter() {
-			super(new AsyncResult<>(null), Arrays.asList(Future.class, ListenableFuture.class));
+			super(new AsyncResult<>(null), List.of(ListenableFuture.class));
 		}
 
 		@Override
@@ -371,7 +369,7 @@ private static class NullableWrapperToCompletableFutureConverter extends Abstrac
 		 * Creates a new {@link NullableWrapperToCompletableFutureConverter} using the given {@link ConversionService}.
 		 */
 		NullableWrapperToCompletableFutureConverter() {
-			super(CompletableFuture.completedFuture(null));
+			super(CompletableFuture.completedFuture(null), List.of(Future.class));
 		}
 
 		@Override

src/test/java/org/springframework/data/repository/util/QueryExecutionConvertersUnitTests.java

@@ -75,6 +75,7 @@ void registersWrapperTypes() {
 		assertThat(QueryExecutionConverters.supports(java.util.Optional.class)).isTrue();
 		assertThat(QueryExecutionConverters.supports(Future.class)).isTrue();
 		assertThat(QueryExecutionConverters.supports(ListenableFuture.class)).isTrue();
+		assertThat(QueryExecutionConverters.supports(CompletableFuture.class)).isTrue();
 		assertThat(QueryExecutionConverters.supports(Option.class)).isTrue();
 		assertThat(QueryExecutionConverters.supports(io.vavr.control.Option.class)).isTrue();
 	}
@@ -85,6 +86,7 @@ void registersUnwrapperTypes() {
 		assertThat(QueryExecutionConverters.supportsUnwrapping(Optional.class)).isTrue();
 		assertThat(QueryExecutionConverters.supportsUnwrapping(java.util.Optional.class)).isTrue();
 		assertThat(QueryExecutionConverters.supportsUnwrapping(Future.class)).isTrue();
+		assertThat(QueryExecutionConverters.supportsUnwrapping(CompletableFuture.class)).isTrue();
 		assertThat(QueryExecutionConverters.supportsUnwrapping(ListenableFuture.class)).isTrue();
 		assertThat(QueryExecutionConverters.supportsUnwrapping(Option.class)).isTrue();
 	}

src/test/java/org/springframework/data/util/NullableWrapperConvertersUnitTests.java

@@ -19,6 +19,7 @@
 
 import scala.Option;
 
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Future;
 
 import org.junit.jupiter.api.BeforeEach;
@@ -54,6 +55,7 @@ void registersWrapperTypes() {
 		assertThat(NullableWrapperConverters.supports(java.util.Optional.class)).isTrue();
 		assertThat(NullableWrapperConverters.supports(Future.class)).isFalse();
 		assertThat(NullableWrapperConverters.supports(ListenableFuture.class)).isFalse();
+		assertThat(NullableWrapperConverters.supports(CompletableFuture.class)).isFalse();
 		assertThat(NullableWrapperConverters.supports(Option.class)).isTrue();
 		assertThat(NullableWrapperConverters.supports(io.vavr.control.Option.class)).isTrue();
 	}
@@ -65,6 +67,7 @@ void registersUnwrapperTypes() {
 		assertThat(NullableWrapperConverters.supportsUnwrapping(java.util.Optional.class)).isTrue();
 		assertThat(NullableWrapperConverters.supportsUnwrapping(Future.class)).isFalse();
 		assertThat(NullableWrapperConverters.supportsUnwrapping(ListenableFuture.class)).isFalse();
+		assertThat(NullableWrapperConverters.supportsUnwrapping(CompletableFuture.class)).isFalse();
 		assertThat(NullableWrapperConverters.supportsUnwrapping(Option.class)).isTrue();
 	}