ClassUtils: deprecate methods with typos

The `ClassUtils.isKotlinFaction0()` and `ClassUtils.isKotlinFaction1()`
are wrong names.

* Deprecate `ClassUtils.isKotlinFaction0()` and `ClassUtils.isKotlinFaction1()`
in favor of newly introduced `isKotlinFunction0()` and `isKotlinFunction1()`

**Cherry-pick to `main`**

Author: artembilan

spring-integration-core/src/main/java/org/springframework/integration/config/annotation/AbstractMethodAnnotationPostProcessor.java

@@ -197,15 +197,6 @@ private MessageHandler registerHandlerBean(String beanName, Method method, final
 		return this.beanFactory.getBean(handlerBeanName, MessageHandler.class);
 	}
 
-	private void orderable(Method method, MessageHandler handler) {
-		if (handler instanceof Orderable) {
-			Order orderAnnotation = AnnotationUtils.findAnnotation(method, Order.class);
-			if (orderAnnotation != null) {
-				((Orderable) handler).setOrder(orderAnnotation.value());
-			}
-		}
-	}
-
 	private void producerOrRouter(List<Annotation> annotations, MessageHandler handler) {
 		if (handler instanceof AbstractMessageProducingHandler || handler instanceof AbstractMessageRouter) {
 			String sendTimeout = MessagingAnnotationUtils.resolveAttribute(annotations, "sendTimeout", String.class);
@@ -608,7 +599,7 @@ protected boolean resolveAttributeToBoolean(String attribute) {
 	@Nullable
 	protected MessageProcessor<?> buildLambdaMessageProcessorForBeanMethod(Method method, Object target) {
 		if ((target instanceof Function || target instanceof Consumer) && ClassUtils.isLambda(target.getClass())
-				|| ClassUtils.isKotlinFaction1(target.getClass())) {
+				|| ClassUtils.isKotlinFunction1(target.getClass())) {
 
 			ResolvableType methodReturnType = ResolvableType.forMethodReturnType(method);
 			Class<?> expectedPayloadType = methodReturnType.getGeneric(0).toClass();
@@ -619,6 +610,15 @@ protected MessageProcessor<?> buildLambdaMessageProcessorForBeanMethod(Method me
 		}
 	}
 
+	private static void orderable(Method method, MessageHandler handler) {
+		if (handler instanceof Orderable) {
+			Order orderAnnotation = AnnotationUtils.findAnnotation(method, Order.class);
+			if (orderAnnotation != null) {
+				((Orderable) handler).setOrder(orderAnnotation.value());
+			}
+		}
+	}
+
 	/**
 	 * Subclasses must implement this method to create the MessageHandler.
 	 * @param bean The bean.

spring-integration-core/src/main/java/org/springframework/integration/config/annotation/InboundChannelAdapterAnnotationPostProcessor.java

@@ -99,11 +99,11 @@ private MessageSource<?> createMessageSource(Object beanArg, String beanNameArg,
 			Class<?> targetClass = target.getClass();
 			Assert.isTrue(MessageSource.class.isAssignableFrom(targetClass) ||
 							Supplier.class.isAssignableFrom(targetClass) ||
-							ClassUtils.isKotlinFaction0(targetClass),
+							ClassUtils.isKotlinFunction0(targetClass),
 					() -> "The '" + this.annotationType + "' on @Bean method " + "level is allowed only for: " +
-							MessageSource.class.getName() + " or " + Supplier.class.getName() +
+							MessageSource.class.getName() + ", or " + Supplier.class.getName() +
 							(ClassUtils.KOTLIN_FUNCTION_0_CLASS != null
-									? " or " + ClassUtils.KOTLIN_FUNCTION_0_CLASS.getName()
+									? ", or " + ClassUtils.KOTLIN_FUNCTION_0_CLASS.getName()
 									: "") + " beans");
 			if (target instanceof MessageSource<?>) {
 				messageSource = (MessageSource<?>) target;

spring-integration-core/src/main/java/org/springframework/integration/util/ClassUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -250,21 +250,46 @@ public static boolean isLambda(Class<?> aClass) {
 	 * @param aClass the {@link Class} to check.
 	 * @return true if class is a {@code kotlin.jvm.functions.Function0} implementation.
 	 * @since 5.2
+	 * @deprecated since 5.5.14 in favor of {@link #isKotlinFunction0(Class)}
 	 */
+	@Deprecated
 	public static boolean isKotlinFaction0(Class<?> aClass) {
 		return KOTLIN_FUNCTION_0_CLASS != null && KOTLIN_FUNCTION_0_CLASS.isAssignableFrom(aClass);
 	}
 
+	/**
+	 * Check if class is {@code kotlin.jvm.functions.Function0}.
+	 * @param aClass the {@link Class} to check.
+	 * @return true if class is a {@code kotlin.jvm.functions.Function0} implementation.
+	 * @since 5.5.14
+	 */
+	public static boolean isKotlinFunction0(Class<?> aClass) {
+		return KOTLIN_FUNCTION_0_CLASS != null && KOTLIN_FUNCTION_0_CLASS.isAssignableFrom(aClass);
+	}
+
 	/**
 	 * Check if class is {@code kotlin.jvm.functions.Function1}.
 	 * @param aClass the {@link Class} to check.
 	 * @return true if class is a {@code kotlin.jvm.functions.Function1} implementation.
 	 * @since 5.2
+	 * @deprecated since 5.5.14 in favor of {@link #isKotlinFunction1(Class)}
 	 */
+	@Deprecated
 	public static boolean isKotlinFaction1(Class<?> aClass) {
 		return KOTLIN_FUNCTION_1_CLASS != null && KOTLIN_FUNCTION_1_CLASS.isAssignableFrom(aClass);
 	}
 
+	/**
+	 * Check if class is {@code kotlin.jvm.functions.Function1}.
+	 * @param aClass the {@link Class} to check.
+	 * @return true if class is a {@code kotlin.jvm.functions.Function1} implementation.
+	 * @since 5.5.14
+	 */
+	public static boolean isKotlinFunction1(Class<?> aClass) {
+		return KOTLIN_FUNCTION_1_CLASS != null && KOTLIN_FUNCTION_1_CLASS.isAssignableFrom(aClass);
+	}
+
+
 	/**
 	 * Check if class is {@code kotlin.Unit}.
 	 * @param aClass the {@link Class} to check.