Performance improvements in ReactiveWrappers and ConvertingPropertyAccessor.

We now cache whether types are reactive wrappers and bypass the ConversionService for assignable primitive values.

Closes #2546

src/main/java/org/springframework/data/mapping/model/ConvertingPropertyAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2021 the original author or authors.
+ * Copyright 2014-2022 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.
@@ -21,6 +21,7 @@ import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.mapping.PersistentPropertyPath;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
 /**
  * {@link PersistentPropertyAccessor} that potentially converts the value handed to
@@ -103,7 +104,7 @@ public class ConvertingPropertyAccessor<T> extends SimplePersistentPropertyPathA
 
 		return (S) (source == null //
 				? null //
-				: type.isAssignableFrom(source.getClass()) //
+				: ClassUtils.resolvePrimitiveIfNecessary(type).isAssignableFrom(source.getClass()) //
 						? source //
 						: conversionService.convert(source, type));
 	}