From 4b80b0f490d43cbb449befa9d2cb8bdd45efee9d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ren=C3=A9=20Wittner?= <95002361+KaidosGH@users.noreply.github.com> Date: Fri, 14 Jul 2023 11:37:09 +0200 Subject: [PATCH] DataAccessUtils result accessors with Optional return value (#27735) --- .../dao/support/DataAccessUtils.java | 87 +++++++++++++++++++ .../dao/support/DataAccessUtilsTests.java | 63 ++++++++++++++ 2 files changed, 150 insertions(+) diff --git a/spring-tx/src/main/java/org/springframework/dao/support/DataAccessUtils.java b/spring-tx/src/main/java/org/springframework/dao/support/DataAccessUtils.java index 20720b36e19..c94ba2211b7 100644 --- a/spring-tx/src/main/java/org/springframework/dao/support/DataAccessUtils.java +++ b/spring-tx/src/main/java/org/springframework/dao/support/DataAccessUtils.java @@ -17,6 +17,10 @@ package org.springframework.dao.support; import java.util.Collection; +import java.util.Iterator; +import java.util.List; +import java.util.Optional; +import java.util.stream.Stream; import org.springframework.dao.DataAccessException; import org.springframework.dao.EmptyResultDataAccessException; @@ -56,6 +60,89 @@ public abstract class DataAccessUtils { return results.iterator().next(); } + /** + * Return a single result object from the given Stream. + *

Returns {@code null} if 0 result objects found; + * throws an exception if more than 1 element found. + * @param results the result Stream (can be {@code null}) + * @return the single result object, or {@code null} if none + * @throws IncorrectResultSizeDataAccessException if more than one + * element has been found in the given Stream + */ + @Nullable + public static T singleResult(@Nullable Stream results) throws IncorrectResultSizeDataAccessException { + if (results == null) { + return null; + } + try (results) { + List resultList = results.limit(2).toList(); + if (resultList.size() > 1) { + throw new IncorrectResultSizeDataAccessException(1); + } + return CollectionUtils.isEmpty(resultList) ? null : resultList.get(0); + } + } + + /** + * Return a single result object from the given Iterator. + *

Returns {@code null} if 0 result objects found; + * throws an exception if more than 1 element found. + * @param results the result Iterator (can be {@code null}) + * @return the single result object, or {@code null} if none + * @throws IncorrectResultSizeDataAccessException if more than one + * element has been found in the given Iterator + */ + @Nullable + public static T singleResult(@Nullable Iterator results) throws IncorrectResultSizeDataAccessException { + if (results == null) { + return null; + } + T result = results.hasNext() ? results.next() : null; + if (results.hasNext()) { + throw new IncorrectResultSizeDataAccessException(1); + } + return result; + } + + /** + * Return a single result object from the given Collection. + *

Returns {@code Optional.empty()} if 0 result objects found; + * throws an exception if more than 1 element found. + * @param results the result Collection (can be {@code null}) + * @return the single optional result object, or {@code Optional.empty()} if none + * @throws IncorrectResultSizeDataAccessException if more than one + * element has been found in the given Collection + */ + public static Optional optionalResult(@Nullable Collection results) throws IncorrectResultSizeDataAccessException { + return Optional.ofNullable(singleResult(results)); + } + + /** + * Return a single result object from the given Stream. + *

Returns {@code Optional.empty()} if 0 result objects found; + * throws an exception if more than 1 element found. + * @param results the result Stream (can be {@code null}) + * @return the single optional result object, or {@code Optional.empty()} if none + * @throws IncorrectResultSizeDataAccessException if more than one + * element has been found in the given Stream + */ + public static Optional optionalResult(@Nullable Stream results) throws IncorrectResultSizeDataAccessException { + return Optional.ofNullable(singleResult(results)); + } + + /** + * Return a single result object from the given Iterator. + *

Returns {@code Optional.empty()} if 0 result objects found; + * throws an exception if more than 1 element found. + * @param results the result Iterator (can be {@code null}) + * @return the single optional result object, or {@code Optional.empty()} if none + * @throws IncorrectResultSizeDataAccessException if more than one + * element has been found in the given Iterator + */ + public static Optional optionalResult(@Nullable Iterator results) throws IncorrectResultSizeDataAccessException { + return Optional.ofNullable(singleResult(results)); + } + /** * Return a single result object from the given Collection. *

Throws an exception if 0 or more than 1 element found. diff --git a/spring-tx/src/test/java/org/springframework/dao/support/DataAccessUtilsTests.java b/spring-tx/src/test/java/org/springframework/dao/support/DataAccessUtilsTests.java index cee7165746a..0cfbbb2036f 100644 --- a/spring-tx/src/test/java/org/springframework/dao/support/DataAccessUtilsTests.java +++ b/spring-tx/src/test/java/org/springframework/dao/support/DataAccessUtilsTests.java @@ -23,6 +23,7 @@ import java.util.Date; import java.util.HashMap; import java.util.HashSet; import java.util.Map; +import java.util.Optional; import java.util.function.Consumer; import org.junit.jupiter.api.Test; @@ -47,6 +48,13 @@ public class DataAccessUtilsTests { assertThat(DataAccessUtils.uniqueResult(col)).isNull(); + assertThat(DataAccessUtils.singleResult(col)).isNull(); + assertThat(DataAccessUtils.singleResult(col.stream())).isNull(); + assertThat(DataAccessUtils.singleResult(col.iterator())).isNull(); + assertThat(DataAccessUtils.optionalResult(col)).isEmpty(); + assertThat(DataAccessUtils.optionalResult(col.stream())).isEmpty(); + assertThat(DataAccessUtils.optionalResult(col.iterator())).isEmpty(); + assertThatExceptionOfType(IncorrectResultSizeDataAccessException.class).isThrownBy(() -> DataAccessUtils.requiredUniqueResult(col)) .satisfies(sizeRequirements(1, 0)); @@ -89,6 +97,30 @@ public class DataAccessUtilsTests { assertThatExceptionOfType(IncorrectResultSizeDataAccessException.class).isThrownBy(() -> DataAccessUtils.longResult(col)) .satisfies(sizeRequirements(1, 2)); + + assertThatExceptionOfType(IncorrectResultSizeDataAccessException.class).isThrownBy(() -> + DataAccessUtils.singleResult(col)) + .satisfies(sizeRequirements(1, 2)); + + assertThatExceptionOfType(IncorrectResultSizeDataAccessException.class).isThrownBy(() -> + DataAccessUtils.singleResult(col.stream())) + .satisfies(sizeRequirements(1)); + + assertThatExceptionOfType(IncorrectResultSizeDataAccessException.class).isThrownBy(() -> + DataAccessUtils.singleResult(col.iterator())) + .satisfies(sizeRequirements(1)); + + assertThatExceptionOfType(IncorrectResultSizeDataAccessException.class).isThrownBy(() -> + DataAccessUtils.optionalResult(col)) + .satisfies(sizeRequirements(1, 2)); + + assertThatExceptionOfType(IncorrectResultSizeDataAccessException.class).isThrownBy(() -> + DataAccessUtils.optionalResult(col.stream())) + .satisfies(sizeRequirements(1)); + + assertThatExceptionOfType(IncorrectResultSizeDataAccessException.class).isThrownBy(() -> + DataAccessUtils.optionalResult(col.iterator())) + .satisfies(sizeRequirements(1)); } @Test @@ -102,6 +134,12 @@ public class DataAccessUtilsTests { assertThat(DataAccessUtils.objectResult(col, String.class)).isEqualTo("5"); assertThat(DataAccessUtils.intResult(col)).isEqualTo(5); assertThat(DataAccessUtils.longResult(col)).isEqualTo(5); + assertThat(DataAccessUtils.singleResult(col)).isEqualTo(5); + assertThat(DataAccessUtils.singleResult(col.stream())).isEqualTo(5); + assertThat(DataAccessUtils.singleResult(col.iterator())).isEqualTo(5); + assertThat(DataAccessUtils.optionalResult(col)).isEqualTo(Optional.of(5)); + assertThat(DataAccessUtils.optionalResult(col.stream())).isEqualTo(Optional.of(5)); + assertThat(DataAccessUtils.optionalResult(col.iterator())).isEqualTo(Optional.of(5)); } @Test @@ -139,6 +177,12 @@ public class DataAccessUtilsTests { assertThat(DataAccessUtils.objectResult(col, String.class)).isEqualTo("5"); assertThat(DataAccessUtils.intResult(col)).isEqualTo(5); assertThat(DataAccessUtils.longResult(col)).isEqualTo(5); + assertThat(DataAccessUtils.singleResult(col)).isEqualTo(Long.valueOf(5L)); + assertThat(DataAccessUtils.singleResult(col.stream())).isEqualTo(Long.valueOf(5L)); + assertThat(DataAccessUtils.singleResult(col.iterator())).isEqualTo(Long.valueOf(5L)); + assertThat(DataAccessUtils.optionalResult(col)).isEqualTo(Optional.of(5L)); + assertThat(DataAccessUtils.optionalResult(col.stream())).isEqualTo(Optional.of(5L)); + assertThat(DataAccessUtils.optionalResult(col.iterator())).isEqualTo(Optional.of(5L)); } @Test @@ -149,6 +193,12 @@ public class DataAccessUtilsTests { assertThat(DataAccessUtils.uniqueResult(col)).isEqualTo("test1"); assertThat(DataAccessUtils.requiredUniqueResult(col)).isEqualTo("test1"); assertThat(DataAccessUtils.objectResult(col, String.class)).isEqualTo("test1"); + assertThat(DataAccessUtils.singleResult(col)).isEqualTo("test1"); + assertThat(DataAccessUtils.singleResult(col.stream())).isEqualTo("test1"); + assertThat(DataAccessUtils.singleResult(col.iterator())).isEqualTo("test1"); + assertThat(DataAccessUtils.optionalResult(col)).isEqualTo(Optional.of("test1")); + assertThat(DataAccessUtils.optionalResult(col.stream())).isEqualTo(Optional.of("test1")); + assertThat(DataAccessUtils.optionalResult(col.iterator())).isEqualTo(Optional.of("test1")); assertThatExceptionOfType(TypeMismatchDataAccessException.class).isThrownBy(() -> DataAccessUtils.intResult(col)); @@ -167,6 +217,12 @@ public class DataAccessUtilsTests { assertThat(DataAccessUtils.requiredUniqueResult(col)).isEqualTo(date); assertThat(DataAccessUtils.objectResult(col, Date.class)).isEqualTo(date); assertThat(DataAccessUtils.objectResult(col, String.class)).isEqualTo(date.toString()); + assertThat(DataAccessUtils.singleResult(col)).isEqualTo(date); + assertThat(DataAccessUtils.singleResult(col.stream())).isEqualTo(date); + assertThat(DataAccessUtils.singleResult(col.iterator())).isEqualTo(date); + assertThat(DataAccessUtils.optionalResult(col)).isEqualTo(Optional.of(date)); + assertThat(DataAccessUtils.optionalResult(col.stream())).isEqualTo(Optional.of(date)); + assertThat(DataAccessUtils.optionalResult(col.iterator())).isEqualTo(Optional.of(date)); assertThatExceptionOfType(TypeMismatchDataAccessException.class).isThrownBy(() -> DataAccessUtils.intResult(col)); @@ -199,6 +255,13 @@ public class DataAccessUtilsTests { }; } + private Consumer sizeRequirements( + int expectedSize) { + return ex -> { + assertThat(ex.getExpectedSize()).as("expected size").isEqualTo(expectedSize); + }; + } + public static class MapPersistenceExceptionTranslator implements PersistenceExceptionTranslator { // in to out