Migrate MediaType.sortByQualityValue() to local implementation by gdgenchev · Pull Request #3856 · cloudfoundry/uaa

gdgenchev · 2026-04-22T06:25:08Z

MediaType.sortByQualityValue() was deprecated in Spring 6 and later removed in Spring 7. Copy the sorting logic into a utility class to preserve content negotiation behavior that respects client quality value preferences from Accept headers.

Exact copy of Spring 6:

https://github.com/spring-projects/spring-framework/blob/9f431e2eac1b6d8d5ca385d0cc367bac94dd37e7/spring-web/src/main/java/org/springframework/http/MediaType.java#L906-L911

https://github.com/spring-projects/spring-framework/blob/9f431e2eac1b6d8d5ca385d0cc367bac94dd37e7/spring-web/src/main/java/org/springframework/http/MediaType.java#L927-L965

https://github.com/spring-projects/spring-framework/blob/9f431e2eac1b6d8d5ca385d0cc367bac94dd37e7/spring-web/src/test/java/org/springframework/http/MediaTypeTests.java#L390-L444 (+ some additional tests for the utility method)

This maintains backward compatibility.

The other approach would be to switch to https://github.com/spring-projects/spring-framework/blob/c6096ff6e5e7de92cf6a3466e211d72b401a0178/spring-core/src/main/java/org/springframework/util/MimeTypeUtils.java#L351-L358

but it will not be backward compatible and we will have to change some ITs that cover this.

…ng 7 Spring 7 removed MediaType.sortByQualityValue() and QUALITY_VALUE_COMPARATOR that were deprecated in Spring 6. Copy the sorting logic into a new MediaTypeComparators utility class to preserve content negotiation behavior that respects client quality value preferences from Accept headers. https://github.com/spring-projects/spring-framework/blob/9f431e2eac1b6d8d5ca385d0cc367bac94dd37e7/spring-web/src/main/java/org/springframework/http/MediaType.java#L927-L965

Copilot

Pull request overview

This PR preserves Spring content-negotiation behavior after MediaType.sortByQualityValue() was removed (Spring 7) by introducing a local MediaType quality-value comparator and updating call sites to use it.

Changes:

Added MediaTypeComparators.BY_QUALITY_VALUE, mirroring Spring 6’s quality-value comparator logic.
Replaced MediaType.sortByQualityValue(...) with acceptedMediaTypes.sort(MediaTypeComparators.BY_QUALITY_VALUE) in two renderers/views.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
`server/src/main/java/org/cloudfoundry/identity/uaa/web/ConvertingExceptionView.java`	Switches Accept media type sorting to the new local comparator.
`server/src/main/java/org/cloudfoundry/identity/uaa/util/MediaTypeComparators.java`	Introduces a Spring-6-compatible `MediaType` quality-value comparator.
`server/src/main/java/org/cloudfoundry/identity/uaa/oauth/provider/error/DefaultOAuth2ExceptionRenderer.java`	Switches Accept media type sorting to the new local comparator.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

- Rename MediaTypeComparators to MediaTypeUtils for better semantics - Add sortByQualityValue() utility method to handle immutable lists - Fix usages to create mutable copies before sorting - Remove unnecessary if-else in ConvertingExceptionView - Add comprehensive unit tests including parameterized tests

Copilot

Pull request overview

This PR preserves UAA’s existing content-negotiation behavior by replacing the removed MediaType.sortByQualityValue(...) API with an equivalent local implementation, ensuring Accept header q (quality) preferences are still respected when selecting response converters.

Changes:

Added MediaTypeUtils with a BY_QUALITY_VALUE comparator and sortByQualityValue(...) method matching Spring 6 behavior.
Updated server-side rendering paths to use MediaTypeUtils.sortByQualityValue(...) instead of the removed Spring API.
Added unit tests covering sorting behavior and comparator edge cases (including stable ordering expectations).

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
`server/src/main/java/org/cloudfoundry/identity/uaa/util/MediaTypeUtils.java`	Introduces the local comparator + sort helper to replace removed Spring API.
`server/src/main/java/org/cloudfoundry/identity/uaa/web/ConvertingExceptionView.java`	Switches Accept sorting to the new local utility before choosing a message converter.
`server/src/main/java/org/cloudfoundry/identity/uaa/oauth/provider/error/DefaultOAuth2ExceptionRenderer.java`	Switches Accept sorting to the new local utility before choosing a message converter.
`server/src/test/java/org/cloudfoundry/identity/uaa/util/MediaTypeUtilsTest.java`	Adds unit coverage to validate ordering, stability, and comparator semantics.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot

Pull request overview

This PR preserves UAA’s Accept-header content negotiation behavior after Spring Framework removed MediaType.sortByQualityValue() by introducing a local equivalent and updating call sites to use it.

Changes:

Added MediaTypeUtils with a Spring 6–compatible quality-value comparator and in-place sort helper.
Replaced usages of MediaType.sortByQualityValue(...) with MediaTypeUtils.sortByQualityValue(...).
Added unit tests covering null handling and comparator behavior.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
server/src/main/java/org/cloudfoundry/identity/uaa/util/MediaTypeUtils.java	New local Spring-6-equivalent comparator + sorting helper for `MediaType`.
server/src/test/java/org/cloudfoundry/identity/uaa/util/MediaTypeUtilsTest.java	New unit tests for the utility comparator/sort behavior.
server/src/main/java/org/cloudfoundry/identity/uaa/web/ConvertingExceptionView.java	Switched Accept sorting to use the local utility.
server/src/main/java/org/cloudfoundry/identity/uaa/oauth/provider/error/DefaultOAuth2ExceptionRenderer.java	Switched Accept sorting to use the local utility.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

+	private MediaTypeUtils() {
+	}
+
+	/**
+	 * Comparator for sorting media types by quality value.
+	 * This implementation preserves the exact sorting logic from Spring Framework 6's
+	 * MediaType.QUALITY_VALUE_COMPARATOR.
+	 */
+	public static final Comparator<MediaType> BY_QUALITY_VALUE = (mediaType1, mediaType2) -> {
+		double quality1 = mediaType1.getQualityValue();
+		double quality2 = mediaType2.getQualityValue();
+		int qualityComparison = Double.compare(quality2, quality1);
+		if (qualityComparison != 0) {
+			return qualityComparison;  // audio/*;q=0.7 < audio/*;q=0.3
+		} else if (mediaType1.isWildcardType() && !mediaType2.isWildcardType()) {  // */* < audio/*
+			return 1;
+		} else if (mediaType2.isWildcardType() && !mediaType1.isWildcardType()) {  // audio/* > */*
+			return -1;
+		} else if (!mediaType1.getType().equals(mediaType2.getType())) {  // audio/basic == text/html
+			return 0;
+		} else {  // mediaType1.getType().equals(mediaType2.getType())
+			if (mediaType1.isWildcardSubtype() && !mediaType2.isWildcardSubtype()) {  // audio/* < audio/basic
+				return 1;
+			} else if (mediaType2.isWildcardSubtype() && !mediaType1.isWildcardSubtype()) {  // audio/basic > audio/*
+				return -1;
+			} else if (!mediaType1.getSubtype().equals(mediaType2.getSubtype())) {  // audio/basic == audio/wave
+				return 0;
+			} else {
+				int paramsSize1 = mediaType1.getParameters().size();
+				int paramsSize2 = mediaType2.getParameters().size();
+				return Integer.compare(paramsSize2, paramsSize1);  // audio/basic;level=1 < audio/basic
+			}
+		}
+	};
+
+	/**
+	 * Sorts the given list of {@code MediaType} objects by quality value.
+	 * This method replicates Spring Framework 6's deprecated MediaType.sortByQualityValue()
+	 * behavior.
+	 *
+	 * @param mediaTypes the list to sort
+	 * @throws IllegalArgumentException if the list is {@code null}
+	 */
+	public static void sortByQualityValue(List<MediaType> mediaTypes) {
+		Assert.notNull(mediaTypes, "'mediaTypes' must not be null");
+		if (mediaTypes.size() > 1) {
+			mediaTypes.sort(BY_QUALITY_VALUE);
+		}
+	}


+	@Test
+	void sortByQualityValueWithNullThrowsException() {
+		assertThatThrownBy(() -> MediaTypeUtils.sortByQualityValue(null))
+				.isInstanceOf(IllegalArgumentException.class)
+				.hasMessageContaining("'mediaTypes' must not be null");
+	}
+
+	@ParameterizedTest
+	@MethodSource("listsThatShouldNotBeSorted")
+	void sortByQualityValueWithListsThatDoNotNeedSorting(List<MediaType> mediaTypes, List<MediaType> expected) {
+		MediaTypeUtils.sortByQualityValue(mediaTypes);
+		assertThat(mediaTypes).isEqualTo(expected);
+	}
+
+	static Stream<Arguments> listsThatShouldNotBeSorted() {
+		return Stream.of(
+				Arguments.of(Collections.emptyList(), Collections.emptyList()),
+				Arguments.of(Collections.singletonList(MediaType.APPLICATION_JSON), Collections.singletonList(MediaType.APPLICATION_JSON))
+		);
+	}
+
+	@Test
+	void sortByQualityValueMaintainsStableSortOrder() {
+		MediaType audioBasic = new MediaType("audio", "basic");
+		MediaType audio = new MediaType("audio");
+		MediaType audio03 = new MediaType("audio", "*", 0.3);
+		MediaType audio07 = new MediaType("audio", "*", 0.7);
+		MediaType audioBasicLevel = new MediaType("audio", "basic", Collections.singletonMap("level", "1"));
+		MediaType all = MediaType.ALL;
+
+		List<MediaType> expected = new ArrayList<>();
+		expected.add(audioBasicLevel);
+		expected.add(audioBasic);
+		expected.add(audio);
+		expected.add(all);
+		expected.add(audio07);
+		expected.add(audio03);
+
+		List<MediaType> result = new ArrayList<>(expected);
+		Random rnd = new Random();
+		// shuffle & sort 10 times
+		for (int i = 0; i < 10; i++) {
+			Collections.shuffle(result, rnd);
+			MediaTypeUtils.sortByQualityValue(result);
+
+			for (int j = 0; j < result.size(); j++) {
+				assertThat(result.get(j)).as("Invalid media type at " + j).isSameAs(expected.get(j));
+			}
+		}
+	}


+	@Test
+	void sortByQualityValueMaintainsStableSortOrder() {
+		MediaType audioBasic = new MediaType("audio", "basic");
+		MediaType audio = new MediaType("audio");
+		MediaType audio03 = new MediaType("audio", "*", 0.3);
+		MediaType audio07 = new MediaType("audio", "*", 0.7);
+		MediaType audioBasicLevel = new MediaType("audio", "basic", Collections.singletonMap("level", "1"));
+		MediaType all = MediaType.ALL;
+
+		List<MediaType> expected = new ArrayList<>();
+		expected.add(audioBasicLevel);
+		expected.add(audioBasic);
+		expected.add(audio);
+		expected.add(all);
+		expected.add(audio07);
+		expected.add(audio03);
+
+		List<MediaType> result = new ArrayList<>(expected);
+		Random rnd = new Random();
+		// shuffle & sort 10 times
+		for (int i = 0; i < 10; i++) {
+			Collections.shuffle(result, rnd);
+			MediaTypeUtils.sortByQualityValue(result);
+
+			for (int j = 0; j < result.size(); j++) {
+				assertThat(result.get(j)).as("Invalid media type at " + j).isSameAs(expected.get(j));
+			}
+		}
+	}


gdgenchev force-pushed the migrate-media-type-sort branch from 6b1a076 to 13ed684 Compare April 22, 2026 06:27

cf-foundation-community-automation Bot added this to Foundational Infrastructure Working Group Apr 22, 2026

cf-foundation-community-automation Bot moved this to Inbox in Foundational Infrastructure Working Group Apr 22, 2026

strehle requested a review from Copilot April 22, 2026 09:07

Copilot started reviewing on behalf of strehle April 22, 2026 09:07 View session

Copilot AI reviewed Apr 22, 2026

View reviewed changes

gdgenchev force-pushed the migrate-media-type-sort branch from e775cb2 to cf69219 Compare April 22, 2026 20:52

strehle requested a review from Copilot April 23, 2026 05:16

Copilot started reviewing on behalf of strehle April 23, 2026 05:16 View session

Copilot AI reviewed Apr 23, 2026

View reviewed changes

strehle requested a review from Copilot April 30, 2026 14:56

strehle assigned duanemay Apr 30, 2026

strehle requested a review from a team April 30, 2026 14:56

strehle unassigned duanemay Apr 30, 2026

strehle requested a review from duanemay April 30, 2026 14:57

Copilot started reviewing on behalf of strehle April 30, 2026 14:57 View session

Copilot AI reviewed Apr 30, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Migrate MediaType.sortByQualityValue() to local implementation#3856

Migrate MediaType.sortByQualityValue() to local implementation#3856
gdgenchev wants to merge 2 commits intocloudfoundry:developfrom
gdgenchev:migrate-media-type-sort

gdgenchev commented Apr 22, 2026 •

edited

Loading

Uh oh!

Copilot AI left a comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI left a comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Conversation

gdgenchev commented Apr 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

gdgenchev commented Apr 22, 2026 •

edited

Loading