Reinstantiate checks for kotlin-reflect

This commit reinstantiates checks for kotlin-reflect (via static final
fields for faster Java code paths and better native code removal) which
were removed as part of gh-34275, which did not consider the
increasingly popular use cases where kotlin-stdlib is present in the
classpath as a transitive dependency in Java applications.

Closes gh-35511

spring-beans/src/main/java/org/springframework/beans/BeanUtils.java

@@ -88,6 +88,8 @@ public abstract class BeanUtils {
 			double.class, 0D,
 			char.class, '\0');
 
+	private static final boolean KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
+
 
 	/**
 	 * Convenience method to instantiate a class using its no-arg constructor.
@@ -186,7 +188,7 @@ public abstract class BeanUtils {
 		Assert.notNull(ctor, "Constructor must not be null");
 		try {
 			ReflectionUtils.makeAccessible(ctor);
-			if (KotlinDetector.isKotlinType(ctor.getDeclaringClass())) {
+			if (KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(ctor.getDeclaringClass())) {
 				return KotlinDelegate.instantiateClass(ctor, args);
 			}
 			else {
@@ -279,7 +281,7 @@ public abstract class BeanUtils {
 	 */
 	public static <T> @Nullable Constructor<T> findPrimaryConstructor(Class<T> clazz) {
 		Assert.notNull(clazz, "Class must not be null");
-		if (KotlinDetector.isKotlinType(clazz)) {
+		if (KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(clazz)) {
 			return KotlinDelegate.findPrimaryConstructor(clazz);
 		}
 		if (clazz.isRecord()) {
@@ -659,7 +661,7 @@ public abstract class BeanUtils {
 		ConstructorProperties cp = ctor.getAnnotation(ConstructorProperties.class);
 		@Nullable String[] paramNames = (cp != null ? cp.value() : parameterNameDiscoverer.getParameterNames(ctor));
 		Assert.state(paramNames != null, () -> "Cannot resolve parameter names for constructor " + ctor);
-		int parameterCount = (KotlinDetector.isKotlinReflectPresent() && KotlinDelegate.hasDefaultConstructorMarker(ctor) ?
+		int parameterCount = (KOTLIN_REFLECT_PRESENT && KotlinDelegate.hasDefaultConstructorMarker(ctor) ?
 				ctor.getParameterCount() - 1 : ctor.getParameterCount());
 		Assert.state(paramNames.length == parameterCount,
 				() -> "Invalid number of parameter names: " + paramNames.length + " for constructor " + ctor);

spring-beans/src/main/java/org/springframework/beans/factory/aot/InstanceSupplierCodeGenerator.java

@@ -88,6 +88,8 @@ public class InstanceSupplierCodeGenerator {
 
 	private static final CodeBlock NO_ARGS = CodeBlock.of("");
 
+	private static final boolean KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
+
 
 	private final GenerationContext generationContext;
 
@@ -161,7 +163,7 @@ public class InstanceSupplierCodeGenerator {
 				registeredBean.getBeanName(), constructor, registeredBean.getBeanClass());
 
 		Class<?> publicType = descriptor.publicType();
-		if (KotlinDetector.isKotlinType(publicType) && KotlinDelegate.hasConstructorWithOptionalParameter(publicType)) {
+		if (KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(publicType) && KotlinDelegate.hasConstructorWithOptionalParameter(publicType)) {
 			return generateCodeForInaccessibleConstructor(descriptor,
 					hints -> hints.registerType(publicType, MemberCategory.INVOKE_DECLARED_CONSTRUCTORS));
 		}

spring-core/src/main/java/org/springframework/core/DefaultParameterNameDiscoverer.java

@@ -35,8 +35,11 @@ package org.springframework.core;
  */
 public class DefaultParameterNameDiscoverer extends PrioritizedParameterNameDiscoverer {
 
+	private static final boolean KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
+
+
 	public DefaultParameterNameDiscoverer() {
-		if (KotlinDetector.isKotlinReflectPresent()) {
+		if (KOTLIN_REFLECT_PRESENT) {
 			addDiscoverer(new KotlinReflectionParameterNameDiscoverer());
 		}
 

spring-core/src/main/java/org/springframework/core/MethodParameter.java

@@ -66,6 +66,8 @@ public class MethodParameter {
 
 	private static final Annotation[] EMPTY_ANNOTATION_ARRAY = new Annotation[0];
 
+	private static final boolean KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
+
 
 	private final Executable executable;
 
@@ -396,7 +398,8 @@ public class MethodParameter {
 	 */
 	public boolean isOptional() {
 		return (getParameterType() == Optional.class || Nullness.forMethodParameter(this) == Nullness.NULLABLE ||
-				(KotlinDetector.isKotlinType(getContainingClass()) && KotlinDelegate.isOptional(this)));
+				(KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(getContainingClass()) &&
+						KotlinDelegate.isOptional(this)));
 	}
 
 	/**
@@ -484,7 +487,7 @@ public class MethodParameter {
 			if (this.parameterIndex < 0) {
 				Method method = getMethod();
 				paramType = (method != null ?
-						(KotlinDetector.isKotlinType(getContainingClass()) ?
+						(KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(getContainingClass()) ?
 								KotlinDelegate.getGenericReturnType(method) : method.getGenericReturnType()) : void.class);
 			}
 			else {
@@ -512,7 +515,7 @@ public class MethodParameter {
 			if (method == null) {
 				return void.class;
 			}
-			if (KotlinDetector.isKotlinType(getContainingClass())) {
+			if (KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(getContainingClass())) {
 				return KotlinDelegate.getReturnType(method);
 			}
 			return method.getReturnType();

spring-core/src/main/java/org/springframework/core/Nullness.java

@@ -77,6 +77,8 @@ public enum Nullness {
 	 */
 	NON_NULL;
 
+	private static final boolean KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
+
 
 	/**
 	 * Return the nullness of the return type for the given method.
@@ -84,7 +86,7 @@ public enum Nullness {
 	 * @return the corresponding nullness
 	 */
 	public static Nullness forMethodReturnType(Method method) {
-		if (KotlinDetector.isKotlinType(method.getDeclaringClass())) {
+		if (KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(method.getDeclaringClass())) {
 			return KotlinDelegate.forMethodReturnType(method);
 		}
 		return (hasNullableAnnotation(method) ? Nullness.NULLABLE :
@@ -97,7 +99,7 @@ public enum Nullness {
 	 * @return the corresponding nullness
 	 */
 	public static Nullness forParameter(Parameter parameter) {
-		if (KotlinDetector.isKotlinType(parameter.getDeclaringExecutable().getDeclaringClass())) {
+		if (KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(parameter.getDeclaringExecutable().getDeclaringClass())) {
 			// TODO Optimize when kotlin-reflect provide a more direct Parameter to KParameter resolution
 			MethodParameter methodParameter = MethodParameter.forParameter(parameter);
 			return KotlinDelegate.forParameter(methodParameter.getExecutable(), methodParameter.getParameterIndex());
@@ -124,7 +126,7 @@ public enum Nullness {
 	 * @return the corresponding nullness
 	 */
 	public static Nullness forField(Field field) {
-		if (KotlinDetector.isKotlinType(field.getDeclaringClass())) {
+		if (KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(field.getDeclaringClass())) {
 			return KotlinDelegate.forField(field);
 		}
 		return (hasNullableAnnotation(field) ? Nullness.NULLABLE :

spring-core/src/main/java/org/springframework/core/io/support/SpringFactoriesLoader.java

@@ -360,8 +360,11 @@ public class SpringFactoriesLoader {
 	 */
 	static final class FactoryInstantiator<T> {
 
+		private static final boolean KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
+
 		private final Constructor<T> constructor;
 
+
 		private FactoryInstantiator(Constructor<T> constructor) {
 			ReflectionUtils.makeAccessible(constructor);
 			this.constructor = constructor;
@@ -369,7 +372,7 @@ public class SpringFactoriesLoader {
 
 		T instantiate(@Nullable ArgumentResolver argumentResolver) throws Exception {
 			Object[] args = resolveArgs(argumentResolver);
-			if (KotlinDetector.isKotlinType(this.constructor.getDeclaringClass())) {
+			if (KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(this.constructor.getDeclaringClass())) {
 				return KotlinDelegate.instantiate(this.constructor, args);
 			}
 			return this.constructor.newInstance(args);

spring-expression/src/main/java/org/springframework/expression/spel/support/ReflectivePropertyAccessor.java

@@ -75,6 +75,9 @@ public class ReflectivePropertyAccessor implements PropertyAccessor {
 
 	private static final Set<Class<?>> BOOLEAN_TYPES = Set.of(Boolean.class, boolean.class);
 
+	private static final boolean KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
+
+
 	private final boolean allowWrite;
 
 	private final Map<PropertyCacheKey, InvokerPair> readerCache = new ConcurrentHashMap<>(64);
@@ -558,7 +561,7 @@ public class ReflectivePropertyAccessor implements PropertyAccessor {
 
 	private static boolean isKotlinProperty(Method method, String methodSuffix) {
 		Class<?> clazz = method.getDeclaringClass();
-		return KotlinDetector.isKotlinType(clazz) &&
+		return KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(clazz) &&
 				KotlinDelegate.isKotlinProperty(method, methodSuffix);
 	}
 

spring-web/src/main/java/org/springframework/web/method/annotation/AbstractNamedValueMethodArgumentResolver.java

@@ -72,6 +72,8 @@ import org.springframework.web.method.support.ModelAndViewContainer;
  */
 public abstract class AbstractNamedValueMethodArgumentResolver implements HandlerMethodArgumentResolver {
 
+	private static final boolean KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
+
 	private final @Nullable ConfigurableBeanFactory configurableBeanFactory;
 
 	private final @Nullable BeanExpressionContext expressionContext;
@@ -103,7 +105,7 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 
 		NamedValueInfo namedValueInfo = getNamedValueInfo(parameter);
 		MethodParameter nestedParameter = parameter.nestedIfOptional();
-		boolean hasDefaultValue = KotlinDetector.isKotlinType(parameter.getDeclaringClass()) &&
+		boolean hasDefaultValue = KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(parameter.getDeclaringClass()) &&
 				KotlinDelegate.hasDefaultValue(nestedParameter);
 
 		Object resolvedName = resolveEmbeddedValuesAndExpressions(namedValueInfo.name);

spring-web/src/main/java/org/springframework/web/method/support/InvocableHandlerMethod.java

@@ -66,6 +66,8 @@ public class InvocableHandlerMethod extends HandlerMethod {
 
 	private static final Class<?>[] EMPTY_GROUPS = new Class<?>[0];
 
+	private static final boolean KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
+
 
 	private HandlerMethodArgumentResolverComposite resolvers = new HandlerMethodArgumentResolverComposite();
 
@@ -247,7 +249,7 @@ public class InvocableHandlerMethod extends HandlerMethod {
 	protected @Nullable Object doInvoke(@Nullable Object... args) throws Exception {
 		Method method = getBridgedMethod();
 		try {
-			if (KotlinDetector.isKotlinType(method.getDeclaringClass())) {
+			if (KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(method.getDeclaringClass())) {
 				if (KotlinDetector.isSuspendingFunction(method)) {
 					return invokeSuspendingFunction(method, getBean(), args);
 				}

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/InvocableHandlerMethod.java

@@ -85,6 +85,8 @@ public class InvocableHandlerMethod extends HandlerMethod {
 
 	private static final Object NO_ARG_VALUE = new Object();
 
+	private static final boolean KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
+
 
 	private final HandlerMethodArgumentResolverComposite resolvers = new HandlerMethodArgumentResolverComposite();
 
@@ -197,12 +199,17 @@ public class InvocableHandlerMethod extends HandlerMethod {
 				}
 			}
 			Object value;
+			boolean isSuspendingFunction;
 			Method method = getBridgedMethod();
-			boolean isSuspendingFunction = KotlinDetector.isSuspendingFunction(method);
 			try {
-				value = (KotlinDetector.isKotlinType(method.getDeclaringClass()) ?
-						KotlinDelegate.invokeFunction(method, getBean(), args, isSuspendingFunction, exchange) :
-						method.invoke(getBean(), args));
+				if (KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(method.getDeclaringClass())) {
+					isSuspendingFunction = KotlinDetector.isSuspendingFunction(method);
+					value = KotlinDelegate.invokeFunction(method, getBean(), args, isSuspendingFunction, exchange);
+				}
+				else {
+					isSuspendingFunction = false;
+					value = method.invoke(getBean(), args);
+				}
 			}
 			catch (IllegalArgumentException ex) {
 				assertTargetBean(getBridgedMethod(), getBean(), args);

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/AbstractNamedValueArgumentResolver.java

@@ -69,6 +69,8 @@ import org.springframework.web.server.ServerWebInputException;
  */
 public abstract class AbstractNamedValueArgumentResolver extends HandlerMethodArgumentResolverSupport {
 
+	private static final boolean KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
+
 	private final @Nullable ConfigurableBeanFactory configurableBeanFactory;
 
 	private final @Nullable BeanExpressionContext expressionContext;
@@ -222,7 +224,7 @@ public abstract class AbstractNamedValueArgumentResolver extends HandlerMethodAr
 
 		return Mono.fromSupplier(() -> {
 			Object value = null;
-			boolean hasDefaultValue = KotlinDetector.isKotlinType(parameter.getDeclaringClass()) &&
+			boolean hasDefaultValue = KOTLIN_REFLECT_PRESENT && KotlinDetector.isKotlinType(parameter.getDeclaringClass()) &&
 					KotlinDelegate.hasDefaultValue(parameter);
 			if (namedValueInfo.defaultValue != null) {
 				value = resolveEmbeddedValuesAndExpressions(namedValueInfo.defaultValue);

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurationSupport.java

@@ -36,6 +36,7 @@ import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Lazy;
+import org.springframework.core.KotlinDetector;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.format.Formatter;
 import org.springframework.format.FormatterRegistry;
@@ -184,6 +185,8 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 
 	private static final boolean JACKSON_2_PRESENT;
 
+	private static final boolean KOTLIN_REFLECT_PRESENT;
+
 	private static final boolean KOTLIN_SERIALIZATION_PRESENT;
 
 
@@ -192,6 +195,7 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 		JACKSON_PRESENT = ClassUtils.isPresent("tools.jackson.databind.ObjectMapper", classLoader);
 		JACKSON_2_PRESENT = ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", classLoader) &&
 				ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator", classLoader);
+		KOTLIN_REFLECT_PRESENT = KotlinDetector.isKotlinReflectPresent();
 		KOTLIN_SERIALIZATION_PRESENT = ClassUtils.isPresent("kotlinx.serialization.Serializable", classLoader);
 	}
 
@@ -659,7 +663,7 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 				requestBodyAdvices.add(new JsonViewRequestBodyAdvice());
 				responseBodyAdvices.add(new JsonViewResponseBodyAdvice());
 			}
-			if (KOTLIN_SERIALIZATION_PRESENT) {
+			if (KOTLIN_REFLECT_PRESENT && KOTLIN_SERIALIZATION_PRESENT) {
 				requestBodyAdvices.add(new KotlinRequestBodyAdvice());
 				responseBodyAdvices.add(new KotlinResponseBodyAdvice());
 			}