Polishing.

Refine deprecation messages. Simplify conversion, use Stream methods directly.

See #2138
Original pull request #2161

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/JdbcAggregateOperations.java

@@ -230,9 +230,11 @@ public interface JdbcAggregateOperations {
 	 * @param pageable the pagination information. Must not be {@code null}.
 	 * @return Guaranteed to be not {@code null}.
 	 * @since 2.0
-	 * @deprecated use a combination of other methods of this class to construct results of type {@link Page}.
+	 * @deprecated since 4.0. Use {@link #findAll(Class, Sort)} together with {@link #count(Class)} to construct results
+	 *             of type {@link Page}.The API design is conflicts regarding pagination information. Also, pagination is
+	 *             primarily a feature of the repository and not the template API.
 	 */
-	@Deprecated(since = "4.0")
+	@Deprecated(since = "4.0", forRemoval = true)
 	<T> Page<T> findAll(Class<T> domainType, Pageable pageable);
 
 	/**
@@ -277,9 +279,11 @@ public interface JdbcAggregateOperations {
 	 * @param pageable can be null.
 	 * @return a {@link Page} of entities matching the given {@link Example}.
 	 * @since 3.0
-	 * @deprecated use a combination of other methods of this class to construct results of type {@link Page}.
+	 * @deprecated since 4.0. Use {@link #findAll(Query, Class)} together with {@link #count(Query, Class)} to construct
+	 *             results of type {@link Page}. The API design is conflicts regarding pagination information. Also,
+	 *             pagination is primarily a feature of the repository and not the template API.
 	 */
-	@Deprecated(since = "4.0")
+	@Deprecated(since = "4.0", forRemoval = true)
 	<T> Page<T> findAll(Query query, Class<T> domainType, Pageable pageable);
 
 	/**

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/JdbcAggregateTemplate.java

@@ -31,6 +31,7 @@ import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 
 import org.jspecify.annotations.Nullable;
+
 import org.springframework.beans.BeansException;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
@@ -41,7 +42,6 @@ import org.springframework.data.domain.Sort;
 import org.springframework.data.jdbc.core.convert.DataAccessStrategy;
 import org.springframework.data.jdbc.core.convert.EntityRowMapper;
 import org.springframework.data.jdbc.core.convert.JdbcConverter;
-import org.springframework.data.jdbc.core.convert.QueryMappingConfiguration;
 import org.springframework.data.mapping.IdentifierAccessor;
 import org.springframework.data.mapping.callback.EntityCallbacks;
 import org.springframework.data.relational.core.EntityLifecycleEventDelegate;
@@ -78,6 +78,7 @@ import org.springframework.util.ClassUtils;
  * @author Sergey Korotaev
  * @author Mikhail Polivakha
  */
+@SuppressWarnings("removal")
 public class JdbcAggregateTemplate implements JdbcAggregateOperations, ApplicationContextAware {
 
 	private final EntityLifecycleEventDelegate eventDelegate = new EntityLifecycleEventDelegate();
@@ -88,7 +89,6 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations, Applicati
 	private final JdbcConverter converter;
 
 	private @Nullable EntityCallbacks entityCallbacks;
-	private QueryMappingConfiguration queryMappingConfiguration = QueryMappingConfiguration.EMPTY;
 
 	/**
 	 * Creates a new {@link JdbcAggregateTemplate} given {@link RelationalMappingContext} and {@link DataAccessStrategy}.
@@ -359,8 +359,8 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations, Applicati
 		return allStreamable.map(this::triggerAfterConvert);
 	}
 
-	@Deprecated
 	@Override
+	@Deprecated(since = "4.0", forRemoval = true)
 	public <T> Page<T> findAll(Class<T> domainType, Pageable pageable) {
 
 		Assert.notNull(domainType, "Domain type must not be null");
@@ -389,8 +389,8 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations, Applicati
 		return accessStrategy.streamAll(query, domainType).map(this::triggerAfterConvert);
 	}
 
-	@Deprecated
 	@Override
+	@Deprecated(since = "4.0", forRemoval = true)
 	public <T> Page<T> findAll(Query query, Class<T> domainType, Pageable pageable) {
 
 		Iterable<T> items = triggerAfterConvert(accessStrategy.findAll(query, domainType, pageable));

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/support/FetchableFluentQueryByExample.java

@@ -16,13 +16,11 @@
 package org.springframework.data.jdbc.repository.support;
 
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.function.Function;
 import java.util.function.UnaryOperator;
 import java.util.stream.Stream;
-import java.util.stream.StreamSupport;
 
 import org.springframework.data.domain.Example;
 import org.springframework.data.domain.OffsetScrollPosition;
@@ -89,16 +87,8 @@ class FetchableFluentQueryByExample<S, R> extends FluentQuerySupport<S, R> {
 
 	private List<R> findAll(Query query) {
 
-		Function<Object, R> conversionFunction = this.getConversionFunction();
-		Iterable<S> raw = this.entityOperations.findAll(query, getExampleType());
-
-		List<R> result = new ArrayList<>(raw instanceof Collections ? ((Collection<?>) raw).size() : 16);
-
-		for (S s : raw) {
-			result.add(conversionFunction.apply(s));
-		}
-
-		return result;
+		List<S> raw = this.entityOperations.findAll(query, getExampleType());
+		return mapContent(raw);
 	}
 
 	@Override
@@ -129,21 +119,33 @@ class FetchableFluentQueryByExample<S, R> extends FluentQuerySupport<S, R> {
 
 		Query contentQuery = createQuery(p -> p.with(pageable));
 		List<S> content = this.entityOperations.findAll(contentQuery, getExampleType());
+		List<R> result = mapContent(content);
+
+		return PageableExecutionUtils.getPage(result, pageable,
+				() -> this.entityOperations.count(createQuery(), getExampleType()));
+	}
+
+	@SuppressWarnings("unchecked")
+	private List<R> mapContent(List<S> content) {
+
+		Function<Object, R> conversionFunction = getConversionFunction();
+
+		if (conversionFunction == Function.identity()) {
+			return (List<R>) content;
+		}
 
 		List<R> result = new ArrayList<>(content.size());
 		for (S s : content) {
-			result.add(getConversionFunction().apply(s));
+			result.add(conversionFunction.apply(s));
 		}
 
-		return PageableExecutionUtils.getPage(result, pageable, () -> this.entityOperations.count(createQuery(), getExampleType()));
+		return result;
 	}
 
 	@Override
 	public Stream<R> stream() {
-
-		return StreamSupport
-				.stream(this.entityOperations.findAll(createQuery().sort(getSort()), getExampleType()).spliterator(), false)
-				.map(item -> this.getConversionFunction().apply(item));
+		return this.entityOperations.streamAll(createQuery().sort(getSort()), getExampleType())
+				.map(getConversionFunction());
 	}
 
 	@Override
@@ -169,7 +171,6 @@ class FetchableFluentQueryByExample<S, R> extends FluentQuerySupport<S, R> {
 		}
 
 		query = query.limit(getLimit());
-
 		query = queryCustomizer.apply(query);
 
 		return query;

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/support/SimpleJdbcRepository.java

@@ -145,10 +145,7 @@ public class SimpleJdbcRepository<T, ID>
 
 		Assert.notNull(pageable, "Pageable must not be null");
 
-		Query query1 = Query.query(CriteriaDefinition.empty());
-
-
-		Query query = query1.with(pageable);
+		Query query = Query.query(CriteriaDefinition.empty()).with(pageable);
 		List<T> content = entityOperations.findAll(query, entity.getType());
 
 		return PageableExecutionUtils.getPage(content, pageable, () -> entityOperations.count(entity.getType()));
@@ -187,11 +184,7 @@ public class SimpleJdbcRepository<T, ID>
 		Assert.notNull(pageable, "Pageable must not be null");
 
 		Query mappedQuery = this.exampleMapper.getMappedExample(example);
-
-
-		Query contentQuery = mappedQuery.with(pageable);
-
-		List<S> content = this.entityOperations.findAll(contentQuery, example.getProbeType());
+		List<S> content = this.entityOperations.findAll(mappedQuery.with(pageable), example.getProbeType());
 
 		return PageableExecutionUtils.getPage(content, pageable,
 				() -> this.entityOperations.count(mappedQuery, example.getProbeType()));

spring-data-jdbc/src/main/kotlin/org/springframework/data/jdbc/core/JdbcAggregateOperationsExtensions.kt

@@ -80,7 +80,7 @@ inline fun <reified T : Any> JdbcAggregateOperations.findAll(sort: Sort): List<T
 /**
  * Extension for [JdbcAggregateOperations.findAll] with pagination.
  */
-@Deprecated("Use a combination of operations of this class to construct results of type Page")
+@Deprecated("Since 4.0, use a findAll<T>() and count<T>() to construct results of type Page")
 inline fun <reified T : Any> JdbcAggregateOperations.findAll(pageable: Pageable): Page<T> =
     findAll(T::class.java, pageable)
 
@@ -99,6 +99,7 @@ inline fun <reified T : Any> JdbcAggregateOperations.findAll(query: Query): List
 /**
  * Extension for [JdbcAggregateOperations.findAll] with query and pagination.
  */
+@Deprecated("Since 4.0, use a findAll<T>(Query) and count<T>(Query) to construct results of type Page")
 inline fun <reified T : Any> JdbcAggregateOperations.findAll(
     query: Query,
     pageable: Pageable