Polishing.

Use FilterFunction instead of nullable fetchSize to avoid unconditional capturing lambdas and improve defaulting.

Add since tag.

See #1652
Original pull request: #1898

spring-data-r2dbc/src/main/java/org/springframework/data/r2dbc/core/R2dbcEntityTemplate.java

@@ -18,6 +18,7 @@ package org.springframework.data.r2dbc.core;
 import io.r2dbc.spi.ConnectionFactory;
 import io.r2dbc.spi.Row;
 import io.r2dbc.spi.RowMetadata;
+import io.r2dbc.spi.Statement;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
@@ -320,7 +321,8 @@ public class R2dbcEntityTemplate implements R2dbcEntityOperations, BeanFactoryAw
 	<T, P extends Publisher<T>> P doSelect(Query query, Class<?> entityClass, SqlIdentifier tableName,
 			Class<T> returnType, Function<RowsFetchSpec<T>, P> resultHandler, @Nullable Integer fetchSize) {
 
-		RowsFetchSpec<T> fetchSpec = doSelect(query, entityClass, tableName, returnType, fetchSize);
+		RowsFetchSpec<T> fetchSpec = doSelect(query, entityClass, tableName, returnType,
+				fetchSize != null ? statement -> statement.fetchSize(fetchSize) : Function.identity());
 
 		P result = resultHandler.apply(fetchSpec);
 
@@ -332,7 +334,7 @@ public class R2dbcEntityTemplate implements R2dbcEntityOperations, BeanFactoryAw
 	}
 
 	private <T> RowsFetchSpec<T> doSelect(Query query, Class<?> entityType, SqlIdentifier tableName,
-			Class<T> returnType, @Nullable Integer fetchSize) {
+			Class<T> returnType, Function<? super Statement, ? extends Statement> filterFunction) {
 
 		StatementMapper statementMapper = dataAccessStrategy.getStatementMapper().forType(entityType);
 
@@ -360,7 +362,7 @@ public class R2dbcEntityTemplate implements R2dbcEntityOperations, BeanFactoryAw
 		PreparedOperation<?> operation = statementMapper.getMappedObject(selectSpec);
 
 		return getRowsFetchSpec(
-			databaseClient.sql(operation).filter((statement) -> statement.fetchSize(Optional.ofNullable(fetchSize).orElse(0))),
+				databaseClient.sql(operation).filter(filterFunction),
 			entityType,
 			returnType
 		);

spring-data-r2dbc/src/main/java/org/springframework/data/r2dbc/core/ReactiveSelectOperation.java

@@ -118,10 +118,12 @@ public interface ReactiveSelectOperation {
 	interface SelectWithQuery<T> extends TerminatingSelect<T> {
 
 		/**
-		 * Specifies the fetch size for this query
+		 * Specifies the fetch size for this query.
 		 *
 		 * @param fetchSize
-		 * @return
+		 * @return new instance of {@link SelectWithQuery}.
+		 * @since 3.4
+		 * @see io.r2dbc.spi.Statement#fetchSize(int)
 		 */
 		SelectWithQuery<T> withFetchSize(int fetchSize);
 

spring-data-r2dbc/src/main/java/org/springframework/data/r2dbc/core/ReactiveSelectOperationSupport.java

@@ -54,7 +54,6 @@ class ReactiveSelectOperationSupport implements ReactiveSelectOperation {
 		private final Class<T> returnType;
 		private final Query query;
 		private final @Nullable SqlIdentifier tableName;
-
 		private final @Nullable Integer fetchSize;
 
 		ReactiveSelectSupport(R2dbcEntityTemplate template, Class<?> domainType, Class<T> returnType, Query query,
@@ -86,9 +85,6 @@ class ReactiveSelectOperationSupport implements ReactiveSelectOperation {
 
 		@Override
 		public SelectWithQuery<T> withFetchSize(int fetchSize) {
-
-			Assert.notNull(returnType, "FetchSize must not be null");
-
 			return new ReactiveSelectSupport<>(template, domainType, returnType, query, tableName, fetchSize);
 		}
 

spring-data-r2dbc/src/test/java/org/springframework/data/r2dbc/core/R2dbcEntityTemplateUnitTests.java

@@ -99,7 +99,7 @@ public class R2dbcEntityTemplateUnitTests {
 				new MappingR2dbcConverter(new R2dbcMappingContext(), conversions));
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldCountBy() {
 
 		MockResult result = MockResult.builder().row(MockRow.builder().identified(0, Long.class, 1L).build()).build();
@@ -117,8 +117,7 @@ public class R2dbcEntityTemplateUnitTests {
 		assertThat(statement.getBindings()).hasSize(1).containsEntry(0, Parameter.from("Walter"));
 	}
 
-	@Test
-	// GH-1690
+	@Test // GH-1690
 	void shouldApplyInterfaceProjection() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -165,7 +164,7 @@ public class R2dbcEntityTemplateUnitTests {
 		assertThat(statement.getSql()).isEqualTo("SELECT foo.* FROM foo WHERE foo.THE_NAME = $1");
 	}
 
-	@Test // gh-469
+	@Test // GH-469
 	void shouldProjectExistsResult() {
 
 		MockResult result = MockResult.builder().row(MockRow.builder().identified(0, Object.class, null).build()).build();
@@ -180,7 +179,7 @@ public class R2dbcEntityTemplateUnitTests {
 				.verifyComplete();
 	}
 
-	@Test // gh-1310
+	@Test // GH-1310
 	void shouldProjectExistsResultWithoutId() {
 
 		MockResult result = MockResult.builder().row(MockRow.builder().identified(0, Object.class, null).build()).build();
@@ -192,7 +191,7 @@ public class R2dbcEntityTemplateUnitTests {
 				.expectNext(true).verifyComplete();
 	}
 
-	@Test // gh-1310
+	@Test // GH-1310
 	void shouldProjectCountResultWithoutId() {
 
 		MockResult result = MockResult.builder().row(MockRow.builder().identified(0, Long.class, 1L).build()).build();
@@ -204,7 +203,7 @@ public class R2dbcEntityTemplateUnitTests {
 				.expectNext(1L).verifyComplete();
 	}
 
-	@Test // gh-469
+	@Test // GH-469
 	void shouldExistsByCriteria() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -224,7 +223,7 @@ public class R2dbcEntityTemplateUnitTests {
 		assertThat(statement.getBindings()).hasSize(1).containsEntry(0, Parameter.from("Walter"));
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldSelectByCriteria() {
 
 		recorder.addStubbing(s -> s.startsWith("SELECT"), Collections.emptyList());
@@ -240,7 +239,7 @@ public class R2dbcEntityTemplateUnitTests {
 		assertThat(statement.getBindings()).hasSize(1).containsEntry(0, Parameter.from("Walter"));
 	}
 
-	@Test // gh-215
+	@Test // GH-215
 	void selectShouldInvokeCallback() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -266,7 +265,7 @@ public class R2dbcEntityTemplateUnitTests {
 		assertThat(callback.getValues()).hasSize(1);
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldSelectOne() {
 
 		recorder.addStubbing(s -> s.startsWith("SELECT"), Collections.emptyList());
@@ -282,7 +281,7 @@ public class R2dbcEntityTemplateUnitTests {
 		assertThat(statement.getBindings()).hasSize(1).containsEntry(0, Parameter.from("Walter"));
 	}
 
-	@Test // gh-220, gh-758
+	@Test // GH-220, GH-758
 	void shouldSelectOneDoNotOverrideExistingLimit() {
 
 		recorder.addStubbing(s -> s.startsWith("SELECT"), Collections.emptyList());
@@ -299,7 +298,7 @@ public class R2dbcEntityTemplateUnitTests {
 		assertThat(statement.getBindings()).hasSize(1).containsEntry(0, Parameter.from("Walter"));
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldUpdateByQuery() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -321,7 +320,7 @@ public class R2dbcEntityTemplateUnitTests {
 				Parameter.from("Walter"));
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldDeleteByQuery() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -341,7 +340,7 @@ public class R2dbcEntityTemplateUnitTests {
 		assertThat(statement.getBindings()).hasSize(1).containsEntry(0, Parameter.from("Walter"));
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldDeleteEntity() {
 
 		Person person = Person.empty() //
@@ -358,7 +357,7 @@ public class R2dbcEntityTemplateUnitTests {
 		assertThat(statement.getBindings()).hasSize(1).containsEntry(0, Parameter.from("Walter"));
 	}
 
-	@Test // gh-365
+	@Test // GH-365
 	void shouldInsertVersioned() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder().build();
@@ -379,7 +378,7 @@ public class R2dbcEntityTemplateUnitTests {
 				Parameter.from(1L));
 	}
 
-	@Test // gh-557, gh-402
+	@Test // GH-557, GH-402
 	void shouldSkipDefaultIdValueOnInsert() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder().build();
@@ -397,7 +396,7 @@ public class R2dbcEntityTemplateUnitTests {
 		assertThat(statement.getBindings()).hasSize(1).containsEntry(0, Parameter.from("bar"));
 	}
 
-	@Test // gh-557, gh-402
+	@Test // GH-557, GH-402
 	void shouldSkipDefaultIdValueOnVersionedInsert() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder().build();
@@ -419,7 +418,7 @@ public class R2dbcEntityTemplateUnitTests {
 				Parameter.from("bar"));
 	}
 
-	@Test // gh-451
+	@Test // GH-451
 	void shouldInsertCorrectlyVersionedAndAudited() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder().build();
@@ -447,7 +446,7 @@ public class R2dbcEntityTemplateUnitTests {
 				"INSERT INTO with_auditing_and_optimistic_locking (version, name, created_date, last_modified_date) VALUES ($1, $2, $3, $4)");
 	}
 
-	@Test // gh-451
+	@Test // GH-451
 	void shouldUpdateCorrectlyVersionedAndAudited() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder().build();
@@ -476,7 +475,7 @@ public class R2dbcEntityTemplateUnitTests {
 				"UPDATE with_auditing_and_optimistic_locking SET version = $1, name = $2, created_date = $3, last_modified_date = $4");
 	}
 
-	@Test // gh-215
+	@Test // GH-215
 	void insertShouldInvokeCallback() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder().build();
@@ -504,7 +503,7 @@ public class R2dbcEntityTemplateUnitTests {
 				Parameter.from("before-save"));
 	}
 
-	@Test // gh-365
+	@Test // GH-365
 	void shouldUpdateVersioned() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder().build();
@@ -526,7 +525,7 @@ public class R2dbcEntityTemplateUnitTests {
 				Parameter.from(1L));
 	}
 
-	@Test // gh-215
+	@Test // GH-215
 	void updateShouldInvokeCallback() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder().build();
@@ -559,7 +558,7 @@ public class R2dbcEntityTemplateUnitTests {
 				Parameter.from("before-save"));
 	}
 
-	@Test // gh-637
+	@Test // GH-637
 	void insertIncludesInsertOnlyColumns() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder().build();
@@ -578,7 +577,7 @@ public class R2dbcEntityTemplateUnitTests {
 				Parameter.from("insert this"));
 	}
 
-	@Test // gh-637
+	@Test // GH-637
 	void updateExcludesInsertOnlyColumns() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder().build();

spring-data-r2dbc/src/test/java/org/springframework/data/r2dbc/core/ReactiveSelectOperationUnitTests.java

@@ -24,11 +24,11 @@ import io.r2dbc.spi.test.MockColumnMetadata;
 import io.r2dbc.spi.test.MockResult;
 import io.r2dbc.spi.test.MockRow;
 import io.r2dbc.spi.test.MockRowMetadata;
-import reactor.core.publisher.Flux;
 import reactor.test.StepVerifier;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+
 import org.springframework.data.annotation.Id;
 import org.springframework.data.r2dbc.dialect.PostgresDialect;
 import org.springframework.data.r2dbc.testing.StatementRecorder;
@@ -56,7 +56,7 @@ public class ReactiveSelectOperationUnitTests {
 		entityTemplate = new R2dbcEntityTemplate(client, new DefaultReactiveDataAccessStrategy(PostgresDialect.INSTANCE));
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldSelectAll() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -80,7 +80,7 @@ public class ReactiveSelectOperationUnitTests {
 				.isEqualTo("SELECT person.* FROM person WHERE person.THE_NAME = $1 LIMIT 10 OFFSET 20");
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldSelectAs() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -128,7 +128,7 @@ public class ReactiveSelectOperationUnitTests {
 		assertThat(statement.getSql()).isEqualTo("SELECT person.id, person.a_different_name FROM person WHERE person.THE_NAME = $1");
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldSelectFromTable() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -152,7 +152,7 @@ public class ReactiveSelectOperationUnitTests {
 		assertThat(statement.getSql()).isEqualTo("SELECT the_table.* FROM the_table WHERE the_table.THE_NAME = $1");
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldSelectFirst() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -175,7 +175,7 @@ public class ReactiveSelectOperationUnitTests {
 		assertThat(statement.getSql()).isEqualTo("SELECT person.* FROM person WHERE person.THE_NAME = $1 LIMIT 1");
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldSelectOne() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -198,7 +198,7 @@ public class ReactiveSelectOperationUnitTests {
 		assertThat(statement.getSql()).isEqualTo("SELECT person.* FROM person WHERE person.THE_NAME = $1 LIMIT 2");
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldSelectExists() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -221,7 +221,7 @@ public class ReactiveSelectOperationUnitTests {
 		assertThat(statement.getSql()).isEqualTo("SELECT 1 FROM person WHERE person.THE_NAME = $1 LIMIT 1");
 	}
 
-	@Test // gh-220
+	@Test // GH-220
 	void shouldSelectCount() {
 
 		MockRowMetadata metadata = MockRowMetadata.builder()
@@ -244,8 +244,9 @@ public class ReactiveSelectOperationUnitTests {
 		assertThat(statement.getSql()).isEqualTo("SELECT COUNT(*) FROM person WHERE person.THE_NAME = $1");
 	}
 
-	@Test // gh-1652
-	void shouldBeAbleToProvideFetchSize() {
+	@Test // GH-1652
+	void shouldConsiderFetchSize() {
+
 		MockRowMetadata metadata = MockRowMetadata.builder()
 				.columnMetadata(MockColumnMetadata.builder().name("id").type(R2dbcType.INTEGER).build())
 				.build();
@@ -256,8 +257,7 @@ public class ReactiveSelectOperationUnitTests {
 		recorder.addStubbing(s -> s.startsWith("SELECT"), result);
 
 		entityTemplate.select(Person.class) //
-				.withFetchSize(10)
-				.matching(query(where("name").is("Walter")).limit(10).offset(20)) //
+				.withFetchSize(10) //
 				.all() //
 				.as(StepVerifier::create) //
 				.expectNextCount(1) //
@@ -265,8 +265,6 @@ public class ReactiveSelectOperationUnitTests {
 
 		StatementRecorder.RecordedStatement statement = recorder.getCreatedStatement(s -> s.startsWith("SELECT"));
 
-		assertThat(statement.getSql())
-				.isEqualTo("SELECT person.* FROM person WHERE person.THE_NAME = $1 LIMIT 10 OFFSET 20");
 		assertThat(statement.getFetchSize()).isEqualTo(10);
 	}