Make sure Web infrastructure uses qualified beans

This commit is a follow-up of a change in Spring Framework[1] to make
sure injection points that are expecting a specific bean by name use
a qualifier.

As a result of this change, MVC uses the dedicated MVC validator again
rather than the general one auto-configured by Spring Boot.

[1] https://github.com/spring-projects/spring-framework/issues/23887

Closes gh-18672

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration.java

@@ -33,6 +33,7 @@ import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.AutoConfigureOrder;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
@@ -362,10 +363,11 @@ public class WebMvcAutoConfiguration {
 		@Bean
 		@Override
 		public RequestMappingHandlerAdapter requestMappingHandlerAdapter(
-				ContentNegotiationManager mvcContentNegotiationManager,
+				@Qualifier("mvcContentNegotiationManager") ContentNegotiationManager contentNegotiationManager,
-				FormattingConversionService mvcConversionService, Validator mvcValidator) {
+				@Qualifier("mvcConversionService") FormattingConversionService conversionService,
-			RequestMappingHandlerAdapter adapter = super.requestMappingHandlerAdapter(mvcContentNegotiationManager,
+				@Qualifier("mvcValidator") Validator validator) {
-					mvcConversionService, mvcValidator);
+			RequestMappingHandlerAdapter adapter = super.requestMappingHandlerAdapter(contentNegotiationManager,
+					conversionService, validator);
 			adapter.setIgnoreDefaultModelOnRedirect(
 					this.mvcProperties == null || this.mvcProperties.isIgnoreDefaultModelOnRedirect());
 			return adapter;
@@ -383,11 +385,12 @@ public class WebMvcAutoConfiguration {
 		@Primary
 		@Override
 		public RequestMappingHandlerMapping requestMappingHandlerMapping(
-				ContentNegotiationManager mvcContentNegotiationManager,
+				@Qualifier("mvcContentNegotiationManager") ContentNegotiationManager contentNegotiationManager,
-				FormattingConversionService mvcConversionService, ResourceUrlProvider mvcResourceUrlProvider) {
+				@Qualifier("mvcConversionService") FormattingConversionService conversionService,
+				@Qualifier("mvcResourceUrlProvider") ResourceUrlProvider resourceUrlProvider) {
 			// Must be @Primary for MvcUriComponentsBuilder to work
-			return super.requestMappingHandlerMapping(mvcContentNegotiationManager, mvcConversionService,
+			return super.requestMappingHandlerMapping(contentNegotiationManager, conversionService,
-					mvcResourceUrlProvider);
+					resourceUrlProvider);
 		}
 
 		@Bean

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfigurationTests.java

@@ -564,15 +564,31 @@ class WebMvcAutoConfigurationTests {
 	}
 
 	@Test
-	void validatorWithConfigurerShouldUseSpringValidator() {
+	void validatorWithConfigurerAloneShouldUseSpringValidator() {
 		this.contextRunner.withUserConfiguration(MvcValidator.class).run((context) -> {
 			assertThat(context).doesNotHaveBean(ValidatorFactory.class);
 			assertThat(context).doesNotHaveBean(javax.validation.Validator.class);
 			assertThat(context).getBeanNames(Validator.class).containsOnly("mvcValidator");
-			assertThat(context.getBean("mvcValidator")).isSameAs(context.getBean(MvcValidator.class).validator);
+			Validator expectedValidator = context.getBean(MvcValidator.class).validator;
+			assertThat(context.getBean("mvcValidator")).isSameAs(expectedValidator);
+			assertThat(context.getBean(RequestMappingHandlerAdapter.class).getWebBindingInitializer())
+					.hasFieldOrPropertyWithValue("validator", expectedValidator);
 		});
 	}
 
+	@Test
+	void validatorWithConfigurerShouldUseSpringValidator() {
+		this.contextRunner.withConfiguration(AutoConfigurations.of(ValidationAutoConfiguration.class))
+				.withUserConfiguration(MvcValidator.class).run((context) -> {
+					assertThat(context).getBeanNames(javax.validation.Validator.class).containsOnly("defaultValidator");
+					assertThat(context).getBeanNames(Validator.class).containsOnly("defaultValidator", "mvcValidator");
+					Validator expectedValidator = context.getBean(MvcValidator.class).validator;
+					assertThat(context.getBean("mvcValidator")).isSameAs(expectedValidator);
+					assertThat(context.getBean(RequestMappingHandlerAdapter.class).getWebBindingInitializer())
+							.hasFieldOrPropertyWithValue("validator", expectedValidator);
+				});
+	}
+
 	@Test
 	void validatorWithConfigurerDoesNotExposeJsr303() {
 		this.contextRunner.withUserConfiguration(MvcJsr303Validator.class).run((context) -> {