Add support for returning `Streamable` from AOT repository methods.

Closes #2175

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/aot/JdbcCodeBlocks.java

@@ -49,6 +49,7 @@ import org.springframework.data.repository.aot.generate.MethodReturn;
 import org.springframework.data.repository.query.parser.Part;
 import org.springframework.data.support.PageableExecutionUtils;
 import org.springframework.data.util.Pair;
+import org.springframework.data.util.Streamable;
 import org.springframework.javapoet.CodeBlock;
 import org.springframework.javapoet.CodeBlock.Builder;
 import org.springframework.javapoet.TypeName;
@@ -811,8 +812,14 @@ class JdbcCodeBlocks {
 					return builder.build();
 				}
 
-				builder.addStatement("return ($T) convertMany($L, %s)".formatted(dynamicProjection ? "$L" : "$T.class"),
-						methodReturn.getTypeName(), result, queryResultTypeRef);
+				if (methodReturn.toClass().equals(Streamable.class)) {
+					builder.addStatement(
+							"return ($1T) $1T.of(($2T) convertMany($3L, %s))".formatted(dynamicProjection ? "$4L" : "$4T.class"),
+							Streamable.class, Iterable.class, result, queryResultTypeRef);
+				} else {
+					builder.addStatement("return ($T) convertMany($L, %s)".formatted(dynamicProjection ? "$L" : "$T.class"),
+							methodReturn.getTypeName(), result, queryResultTypeRef);
+				}
 			} else if (queryMethod.isStreamQuery()) {
 
 				builder.addStatement("$1T $2L = " + decorator.decorate("getJdbcOperations().queryForStream($3L, $4L, $5L)"),

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/repository/aot/JdbcRepositoryContributorIntegrationTests.java

@@ -47,6 +47,7 @@ import org.springframework.data.jdbc.testing.EnabledOnDatabase;
 import org.springframework.data.jdbc.testing.IntegrationTest;
 import org.springframework.data.jdbc.testing.TestClass;
 import org.springframework.data.jdbc.testing.TestConfiguration;
+import org.springframework.data.util.Streamable;
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
 
 /**
@@ -188,6 +189,14 @@ class JdbcRepositoryContributorIntegrationTests {
 		assertThat(users).hasSize(2);
 	}
 
+	@Test // GH-2175
+	void shouldReturnStreamable() {
+
+		Streamable<User> users = fragment.findStreamableByAgeBetween(40, 51);
+
+		assertThat(users).hasSize(2);
+	}
+
 	@Test // GH-2121
 	void streamByAgeGreaterThan() {
 		assertThat(fragment.streamByAgeGreaterThan(20)).hasSize(5);
@@ -221,6 +230,14 @@ class JdbcRepositoryContributorIntegrationTests {
 		assertThat(page.hasNext()).isFalse();
 	}
 
+	@Test // GH-2175
+	void shouldReturnPagedStreamable() {
+
+		Streamable<User> result = fragment.findStreamableByAgeGreaterThan(PageRequest.of(0, 4, Sort.by("age")), 10);
+
+		assertThat(result).hasSize(4);
+	}
+
 	@Test // GH-2121
 	void countByAgeLessThan() {
 
@@ -313,6 +330,14 @@ class JdbcRepositoryContributorIntegrationTests {
 		assertThat(users).hasSize(6);
 	}
 
+	@Test // GH-2175
+	void shouldReturnStreamableFromDeclaredQuery() {
+
+		Streamable<User> users = fragment.findStreamableCreatedBefore(Instant.now().plusSeconds(180));
+
+		assertThat(users).hasSize(6);
+	}
+
 	@Test // GH-2174
 	void shouldSupportDeclaredQueryWithAggregateReference() {
 

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/repository/aot/UserRepository.java

@@ -28,6 +28,7 @@ import org.springframework.data.jdbc.repository.query.Modifying;
 import org.springframework.data.jdbc.repository.query.Query;
 import org.springframework.data.repository.CrudRepository;
 import org.springframework.data.repository.query.Param;
+import org.springframework.data.util.Streamable;
 
 public interface UserRepository extends CrudRepository<User, Integer> {
 
@@ -51,6 +52,8 @@ public interface UserRepository extends CrudRepository<User, Integer> {
 
 	List<User> findAllByAgeBetween(int start, int end);
 
+	Streamable<User> findStreamableByAgeBetween(int start, int end);
+
 	Optional<User> findOptionalByFirstname(String name);
 
 	Stream<User> streamByAgeGreaterThan(int age);
@@ -67,6 +70,8 @@ public interface UserRepository extends CrudRepository<User, Integer> {
 
 	Page<User> findPageByAgeGreaterThan(Pageable pageable, int age);
 
+	Streamable<User> findStreamableByAgeGreaterThan(Pageable pageable, int age);
+
 	// -------------------------------------------------------------------------
 	// Declared Queries
 	// -------------------------------------------------------------------------
@@ -97,6 +102,9 @@ public interface UserRepository extends CrudRepository<User, Integer> {
 	@Query(value = "SELECT * FROM MY_USER WHERE created < :instant")
 	List<User> findCreatedBefore(Instant instant);
 
+	@Query(value = "SELECT * FROM MY_USER WHERE created < :instant")
+	Streamable<User> findStreamableCreatedBefore(Instant instant);
+
 	// -------------------------------------------------------------------------
 	// Parameter naming
 	// -------------------------------------------------------------------------