Skip validation constraint hint inference if no provider available

Closes gh-30130

Author: jhoeller

spring-context/src/main/java/org/springframework/validation/beanvalidation/BeanValidationBeanRegistrationAotProcessor.java

@@ -21,6 +21,7 @@
 import java.util.Set;
 
 import jakarta.validation.ConstraintValidator;
+import jakarta.validation.NoProviderFoundException;
 import jakarta.validation.Validation;
 import jakarta.validation.Validator;
 import jakarta.validation.metadata.BeanDescriptor;
@@ -48,6 +49,7 @@
  * required for {@link ConstraintValidator}s.
  *
  * @author Sebastien Deleuze
+ * @author Juergen Hoeller
  * @since 6.0.5
  */
 class BeanValidationBeanRegistrationAotProcessor implements BeanRegistrationAotProcessor {
@@ -57,21 +59,39 @@ class BeanValidationBeanRegistrationAotProcessor implements BeanRegistrationAotP
 
 	private static final Log logger = LogFactory.getLog(BeanValidationBeanRegistrationAotProcessor.class);
 
-	@Nullable
+
 	@Override
+	@Nullable
 	public BeanRegistrationAotContribution processAheadOfTime(RegisteredBean registeredBean) {
 		if (isBeanValidationPresent) {
 			return BeanValidationDelegate.processAheadOfTime(registeredBean);
 		}
 		return null;
 	}
 
+
 	private static class BeanValidationDelegate {
 
-		private static final Validator validator = Validation.buildDefaultValidatorFactory().getValidator();
+		@Nullable
+		private static final Validator validator = getValidatorIfAvailable();
+
+		@Nullable
+		private static Validator getValidatorIfAvailable() {
+			try {
+				return Validation.buildDefaultValidatorFactory().getValidator();
+			}
+			catch (NoProviderFoundException ex) {
+				logger.info("No Bean Validation provider available - skipping validation constraint hint inference");
+				return null;
+			}
+		}
 
 		@Nullable
 		public static BeanRegistrationAotContribution processAheadOfTime(RegisteredBean registeredBean) {
+			if (validator == null) {
+				return null;
+			}
+
 			BeanDescriptor descriptor;
 			try {
 				descriptor = validator.getConstraintsForClass(registeredBean.getBeanClass());
@@ -88,6 +108,7 @@ public static BeanRegistrationAotContribution processAheadOfTime(RegisteredBean
 				}
 				return null;
 			}
+
 			Set<ConstraintDescriptor<?>> constraintDescriptors = new HashSet<>();
 			for (MethodDescriptor methodDescriptor : descriptor.getConstrainedMethods(MethodType.NON_GETTER, MethodType.GETTER)) {
 				for (ParameterDescriptor parameterDescriptor : methodDescriptor.getParameterDescriptors()) {
@@ -107,9 +128,9 @@ public static BeanRegistrationAotContribution processAheadOfTime(RegisteredBean
 			}
 			return null;
 		}
-
 	}
 
+
 	private static class BeanValidationBeanRegistrationAotContribution implements BeanRegistrationAotContribution {
 
 		private final Collection<ConstraintDescriptor<?>> constraintDescriptors;