Merge branch '5.2.x'

# Conflicts:
#	spring-jdbc/src/test/java/org/springframework/jdbc/core/JdbcTemplateQueryTests.java
#	spring-jdbc/src/test/java/org/springframework/jdbc/core/namedparam/NamedParameterJdbcTemplateTests.java

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

@@ -105,7 +105,7 @@ public final class ReactiveTypeDescriptor {
 	 * Whether the underlying operation is deferred and needs to be started
 	 * explicitly, e.g. via subscribing (or similar), or whether it is triggered
 	 * without the consumer having any control.
-	 * @since 5.1.16
+	 * @since 5.2.7
 	 */
 	public boolean isDeferred() {
 		return this.deferred;
@@ -169,7 +169,7 @@ public final class ReactiveTypeDescriptor {
 	 * non-deferred, async type such as {@link java.util.concurrent.CompletableFuture}.
 	 * @param type the reactive type
 	 * @param emptySupplier a supplier of an empty-value instance of the reactive type
-	 * @since 5.1.16
+	 * @since 5.2.7
 	 */
 	public static ReactiveTypeDescriptor nonDeferredAsyncValue(Class<?> type, Supplier<?> emptySupplier) {
 		return new ReactiveTypeDescriptor(type, false, false, emptySupplier, false);

spring-core/src/main/java/org/springframework/core/serializer/Deserializer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.core.serializer;
 
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 
@@ -24,8 +25,10 @@ import java.io.InputStream;
  *
  * @author Gary Russell
  * @author Mark Fisher
+ * @author Juergen Hoeller
  * @since 3.0.5
  * @param <T> the object type
+ * @see Serializer
  */
 @FunctionalInterface
 public interface Deserializer<T> {
@@ -41,4 +44,15 @@ public interface Deserializer<T> {
 	 */
 	T deserialize(InputStream inputStream) throws IOException;
 
+	/**
+	 * Read (assemble) an object of type T from the given byte array.
+	 * @param serialized the byte array
+	 * @return the deserialized object
+	 * @throws IOException in case of deserialization failure
+	 * @since 5.2.7
+	 */
+	default T deserializeFromByteArray(byte[] serialized) throws IOException {
+		return deserialize(new ByteArrayInputStream(serialized));
+	}
+
 }

spring-core/src/main/java/org/springframework/core/serializer/Serializer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.core.serializer;
 
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 
@@ -24,8 +25,10 @@ import java.io.OutputStream;
  *
  * @author Gary Russell
  * @author Mark Fisher
+ * @author Juergen Hoeller
  * @since 3.0.5
  * @param <T> the object type
+ * @see Deserializer
  */
 @FunctionalInterface
 public interface Serializer<T> {
@@ -41,4 +44,17 @@ public interface Serializer<T> {
 	 */
 	void serialize(T object, OutputStream outputStream) throws IOException;
 
+	/**
+	 * Turn an object of type T into a serialized byte array.
+	 * @param object the object to serialize
+	 * @return the resulting byte array
+	 * @throws IOException in case of serialization failure
+	 * @since 5.2.7
+	 */
+	default byte[] serializeToByteArray(T object) throws IOException {
+		ByteArrayOutputStream out = new ByteArrayOutputStream(1024);
+		serialize(object, out);
+		return out.toByteArray();
+	}
+
 }

spring-core/src/main/java/org/springframework/core/serializer/support/SerializingConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -16,8 +16,6 @@
 
 package org.springframework.core.serializer.support;
 
-import java.io.ByteArrayOutputStream;
-
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.serializer.DefaultSerializer;
 import org.springframework.core.serializer.Serializer;
@@ -58,10 +56,8 @@ public class SerializingConverter implements Converter<Object, byte[]> {
 	 */
 	@Override
 	public byte[] convert(Object source) {
-		ByteArrayOutputStream byteStream = new ByteArrayOutputStream(1024);
 		try  {
-			this.serializer.serialize(source, byteStream);
-			return byteStream.toByteArray();
+			return this.serializer.serializeToByteArray(source);
 		}
 		catch (Throwable ex) {
 			throw new SerializationFailedException("Failed to serialize object using " +