Polishing

spring-messaging/src/main/java/org/springframework/messaging/converter/AbstractMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 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.
@@ -92,7 +92,7 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 	}
 
 	/**
-	 * Allows sub-classes to add more supported mime types.
+	 * Allows subclasses to add more supported mime types.
 	 * @since 5.2.2
 	 */
 	protected void addSupportedMimeTypes(MimeType... supportedMimeTypes) {
@@ -167,21 +167,6 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 	}
 
 
-	/**
-	 * Returns the default content type for the payload. Called when
-	 * {@link #toMessage(Object, MessageHeaders)} is invoked without message headers or
-	 * without a content type header.
-	 * <p>By default, this returns the first element of the {@link #getSupportedMimeTypes()
-	 * supportedMimeTypes}, if any. Can be overridden in sub-classes.
-	 * @param payload the payload being converted to message
-	 * @return the content type, or {@code null} if not known
-	 */
-	@Nullable
-	protected MimeType getDefaultContentType(Object payload) {
-		List<MimeType> mimeTypes = getSupportedMimeTypes();
-		return (!mimeTypes.isEmpty() ? mimeTypes.get(0) : null);
-	}
-
 	@Override
 	@Nullable
 	public final Object fromMessage(Message<?> message, Class<?> targetClass) {
@@ -197,10 +182,6 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 		return convertFromInternal(message, targetClass, conversionHint);
 	}
 
-	protected boolean canConvertFrom(Message<?> message, Class<?> targetClass) {
-		return (supports(targetClass) && supportsMimeType(message.getHeaders()));
-	}
-
 	@Override
 	@Nullable
 	public final Message<?> toMessage(Object payload, @Nullable MessageHeaders headers) {
@@ -240,6 +221,11 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 		return builder.build();
 	}
 
+
+	protected boolean canConvertFrom(Message<?> message, Class<?> targetClass) {
+		return (supports(targetClass) && supportsMimeType(message.getHeaders()));
+	}
+
 	protected boolean canConvertTo(Object payload, @Nullable MessageHeaders headers) {
 		return (supports(payload.getClass()) && supportsMimeType(headers));
 	}
@@ -265,6 +251,22 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 		return (headers != null && this.contentTypeResolver != null ? this.contentTypeResolver.resolve(headers) : null);
 	}
 
+	/**
+	 * Return the default content type for the payload. Called when
+	 * {@link #toMessage(Object, MessageHeaders)} is invoked without
+	 * message headers or without a content type header.
+	 * <p>By default, this returns the first element of the
+	 * {@link #getSupportedMimeTypes() supportedMimeTypes}, if any.
+	 * Can be overridden in subclasses.
+	 * @param payload the payload being converted to a message
+	 * @return the content type, or {@code null} if not known
+	 */
+	@Nullable
+	protected MimeType getDefaultContentType(Object payload) {
+		List<MimeType> mimeTypes = getSupportedMimeTypes();
+		return (!mimeTypes.isEmpty() ? mimeTypes.get(0) : null);
+	}
+
 
 	/**
 	 * Whether the given class is supported by this converter.

spring-messaging/src/main/java/org/springframework/messaging/converter/MappingJackson2MessageConverter.java

@@ -41,6 +41,7 @@ import org.springframework.lang.Nullable;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageHeaders;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.MimeType;
 
 /**
@@ -139,6 +140,7 @@ public class MappingJackson2MessageConverter extends AbstractMessageConverter {
 		}
 	}
 
+
 	@Override
 	protected boolean canConvertFrom(Message<?> message, @Nullable Class<?> targetClass) {
 		if (targetClass == null || !supportsMimeType(message.getHeaders())) {
@@ -210,7 +212,7 @@ public class MappingJackson2MessageConverter extends AbstractMessageConverter {
 		Object payload = message.getPayload();
 		Class<?> view = getSerializationView(conversionHint);
 		try {
-			if (targetClass.isInstance(payload)) {
+			if (ClassUtils.isAssignableValue(targetClass, payload)) {
 				return payload;
 			}
 			else if (payload instanceof byte[]) {
@@ -246,7 +248,7 @@ public class MappingJackson2MessageConverter extends AbstractMessageConverter {
 			Type genericParameterType = param.getNestedGenericParameterType();
 			Class<?> contextClass = param.getContainingClass();
 			Type type = GenericTypeResolver.resolveType(genericParameterType, contextClass);
-			return this.objectMapper.getTypeFactory().constructType(type);
+			return this.objectMapper.constructType(type);
 		}
 		return this.objectMapper.constructType(targetClass);
 	}
@@ -331,7 +333,7 @@ public class MappingJackson2MessageConverter extends AbstractMessageConverter {
 	 * @return the JSON encoding to use (never {@code null})
 	 */
 	protected JsonEncoding getJsonEncoding(@Nullable MimeType contentType) {
-		if (contentType != null && (contentType.getCharset() != null)) {
+		if (contentType != null && contentType.getCharset() != null) {
 			Charset charset = contentType.getCharset();
 			for (JsonEncoding encoding : JsonEncoding.values()) {
 				if (charset.name().equals(encoding.getJavaName())) {

spring-messaging/src/main/java/org/springframework/messaging/converter/MarshallingMessageConverter.java

@@ -46,6 +46,8 @@ import org.springframework.util.MimeType;
  *
  * @author Arjen Poutsma
  * @since 4.2
+ * @see Marshaller
+ * @see Unmarshaller
  */
 public class MarshallingMessageConverter extends AbstractMessageConverter {
 
@@ -61,7 +63,8 @@ public class MarshallingMessageConverter extends AbstractMessageConverter {
 	 * {@link #setUnmarshaller(Unmarshaller)} to be invoked separately.
 	 */
 	public MarshallingMessageConverter() {
-		this(new MimeType("application", "xml"), new MimeType("text", "xml"), new MimeType("application", "*+xml"));
+		this(new MimeType("application", "xml"), new MimeType("text", "xml"),
+				new MimeType("application", "*+xml"));
 	}
 
 	/**
@@ -160,7 +163,7 @@ public class MarshallingMessageConverter extends AbstractMessageConverter {
 			return new StreamSource(new ByteArrayInputStream((byte[]) payload));
 		}
 		else {
-			return new StreamSource(new StringReader((String) payload));
+			return new StreamSource(new StringReader(payload.toString()));
 		}
 	}
 

spring-messaging/src/main/java/org/springframework/messaging/converter/ProtobufMessageConverter.java

@@ -120,9 +120,9 @@ public class ProtobufMessageConverter extends AbstractMessageConverter {
 
 	@Override
 	protected boolean canConvertTo(Object payload, @Nullable MessageHeaders headers) {
-		MimeType mimeType = getMimeType(headers);
+		MimeType contentType = getMimeType(headers);
 		return (super.canConvertTo(payload, headers) ||
-				this.protobufFormatSupport != null && this.protobufFormatSupport.supportsWriteOnly(mimeType));
+				this.protobufFormatSupport != null && this.protobufFormatSupport.supportsWriteOnly(contentType));
 	}
 
 	@Override