Merge branch '2.5.x'

Closes gh-28469

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/ProducibleOperationArgumentResolver.java

@@ -65,7 +65,7 @@ public class ProducibleOperationArgumentResolver implements OperationArgumentRes
 		Enum<? extends Producible<?>> result = null;
 		for (String accept : accepts) {
 			for (String mimeType : MimeTypeUtils.tokenize(accept)) {
-				result = mostRecent(result, forMimeType(values, mimeType));
+				result = mostRecent(result, forMimeType(values, MimeTypeUtils.parseMimeType(mimeType)));
 			}
 		}
 		return result;
@@ -78,14 +78,10 @@ public class ProducibleOperationArgumentResolver implements OperationArgumentRes
 		return (candidateOrdinal > existingOrdinal) ? candidate : existing;
 	}
 
-	private Enum<? extends Producible<?>> forMimeType(List<Enum<? extends Producible<?>>> values, String mimeType) {
-		if ("*/*".equals(mimeType)) {
+	private Enum<? extends Producible<?>> forMimeType(List<Enum<? extends Producible<?>>> values, MimeType mimeType) {
+		if (mimeType.isWildcardType() && mimeType.isWildcardSubtype()) {
 			return getDefaultValue(values);
 		}
-		return forMimeType(values, MimeTypeUtils.parseMimeType(mimeType));
-	}
-
-	private Enum<? extends Producible<?>> forMimeType(List<Enum<? extends Producible<?>>> values, MimeType mimeType) {
 		for (Enum<? extends Producible<?>> candidate : values) {
 			if (mimeType.isCompatibleWith(((Producible<?>) candidate).getProducedMimeType())) {
 				return candidate;

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/export/prometheus/PrometheusScrapeEndpointIntegrationTests.java

@@ -41,12 +41,25 @@ class PrometheusScrapeEndpointIntegrationTests {
 
 	@WebEndpointTest
 	void scrapeHasContentTypeText004ByDefault(WebTestClient client) {
+		String expectedContentType = TextFormat.CONTENT_TYPE_004;
+		assertThat(TextFormat.chooseContentType(null)).isEqualTo(expectedContentType);
 		client.get().uri("/actuator/prometheus").exchange().expectStatus().isOk().expectHeader()
-				.contentType(MediaType.parseMediaType(TextFormat.CONTENT_TYPE_004)).expectBody(String.class)
+				.contentType(MediaType.parseMediaType(expectedContentType)).expectBody(String.class)
 				.value((body) -> assertThat(body).contains("counter1_total").contains("counter2_total")
 						.contains("counter3_total"));
 	}
 
+	@WebEndpointTest
+	void scrapeHasContentTypeText004ByDefaultWhenClientAcceptsWildcardWithParameter(WebTestClient client) {
+		String expectedContentType = TextFormat.CONTENT_TYPE_004;
+		String accept = "*/*;q=0.8";
+		assertThat(TextFormat.chooseContentType(accept)).isEqualTo(expectedContentType);
+		client.get().uri("/actuator/prometheus").accept(MediaType.parseMediaType(accept)).exchange().expectStatus()
+				.isOk().expectHeader().contentType(MediaType.parseMediaType(expectedContentType))
+				.expectBody(String.class).value((body) -> assertThat(body).contains("counter1_total")
+						.contains("counter2_total").contains("counter3_total"));
+	}
+
 	@WebEndpointTest
 	void scrapeCanProduceOpenMetrics100(WebTestClient client) {
 		MediaType openMetrics = MediaType.parseMediaType(TextFormat.CONTENT_TYPE_OPENMETRICS_100);