Polishing

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 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.
@@ -151,21 +151,6 @@ 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) {
@@ -181,10 +166,6 @@ 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) {
@@ -224,6 +205,11 @@ 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));
 	}
@@ -249,6 +235,22 @@ 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

@@ -43,6 +43,7 @@ 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;
 
 /**
@@ -141,6 +142,7 @@ public class MappingJackson2MessageConverter extends AbstractMessageConverter {
 		}
 	}
 
+
 	@Override
 	protected boolean canConvertFrom(Message<?> message, @Nullable Class<?> targetClass) {
 		if (targetClass == null || !supportsMimeType(message.getHeaders())) {
@@ -212,7 +214,7 @@ 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[]) {
@@ -248,7 +250,7 @@ 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);
 	}
@@ -333,7 +335,7 @@ 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

@@ -47,6 +47,8 @@ import org.springframework.util.MimeType;
  *
  * @author Arjen Poutsma
  * @since 4.2
+ * @see Marshaller
+ * @see Unmarshaller
  */
 public class MarshallingMessageConverter extends AbstractMessageConverter {
 
@@ -62,7 +64,8 @@ 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"));
 	}
 
 	/**
@@ -161,7 +164,7 @@ 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/test/java/org/springframework/messaging/converter/MappingJackson2MessageConverterTests.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.
@@ -75,13 +75,8 @@ public class MappingJackson2MessageConverterTests {
 	@Test
 	public void fromMessage() {
 		MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
-		String payload = "{" +
-				"\"bytes\":\"AQI=\"," +
-				"\"array\":[\"Foo\",\"Bar\"]," +
-				"\"number\":42," +
-				"\"string\":\"Foo\"," +
-				"\"bool\":true," +
-				"\"fraction\":42.0}";
+		String payload = "{\"bytes\":\"AQI=\",\"array\":[\"Foo\",\"Bar\"]," +
+				"\"number\":42,\"string\":\"Foo\",\"bool\":true,\"fraction\":42.0}";
 		Message<?> message = MessageBuilder.withPayload(payload.getBytes(StandardCharsets.UTF_8)).build();
 		MyBean actual = (MyBean) converter.fromMessage(message, MyBean.class);
 
@@ -245,9 +240,12 @@ public class MappingJackson2MessageConverterTests {
 	public void jsonViewPayload(@JsonView(MyJacksonView2.class) JacksonViewBean payload) {
 	}
 
-	void handleList(List<Long> payload) {}
+	void handleList(List<Long> payload) {
+	}
+
+	void handleMessage(Message<MyBean> message) {
+	}
 
-	void handleMessage(Message<MyBean> message) {}
 
 	public static class MyBean {