Merge pull request #24087

Closes gh-24087

spring-messaging/spring-messaging.gradle

@@ -13,6 +13,7 @@ dependencies {
 	optional("io.rsocket:rsocket-transport-netty")
 	optional("com.fasterxml.jackson.core:jackson-databind")
 	optional("javax.xml.bind:jaxb-api")
+	optional("com.google.protobuf:protobuf-java-util")
 	optional("org.jetbrains.kotlinx:kotlinx-coroutines-core")
 	optional("org.jetbrains.kotlinx:kotlinx-coroutines-reactor")
 	testCompile("javax.inject:javax.inject-tck")

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -17,6 +17,7 @@
 package org.springframework.messaging.converter;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -47,7 +48,7 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 
 	protected final Log logger = LogFactory.getLog(getClass());
 
-	private final List<MimeType> supportedMimeTypes;
+	private final List<MimeType> supportedMimeTypes = new ArrayList<>(4);
 
 	@Nullable
 	private ContentTypeResolver contentTypeResolver = new DefaultContentTypeResolver();
@@ -58,21 +59,28 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 
 
 	/**
-	 * Construct an {@code AbstractMessageConverter} supporting a single MIME type.
+	 * Constructor with a single MIME type.
 	 * @param supportedMimeType the supported MIME type
 	 */
 	protected AbstractMessageConverter(MimeType supportedMimeType) {
-		Assert.notNull(supportedMimeType, "supportedMimeType is required");
-		this.supportedMimeTypes = Collections.<MimeType>singletonList(supportedMimeType);
+		this(Collections.singletonList(supportedMimeType));
 	}
 
 	/**
-	 * Construct an {@code AbstractMessageConverter} supporting multiple MIME types.
+	 * Constructor with one or more MIME types via vararg.
+	 * @param supportedMimeTypes the supported MIME types
+	 * @since 5.2.2
+	 */
+	protected AbstractMessageConverter(MimeType... supportedMimeTypes) {
+		this(Arrays.asList(supportedMimeTypes));
+	}
+
+	/**
+	 * Constructor with a Collection of MIME types.
 	 * @param supportedMimeTypes the supported MIME types
 	 */
 	protected AbstractMessageConverter(Collection<MimeType> supportedMimeTypes) {
-		Assert.notNull(supportedMimeTypes, "supportedMimeTypes must not be null");
-		this.supportedMimeTypes = new ArrayList<>(supportedMimeTypes);
+		this.supportedMimeTypes.addAll(supportedMimeTypes);
 	}
 
 
@@ -83,6 +91,14 @@ public List<MimeType> getSupportedMimeTypes() {
 		return Collections.unmodifiableList(this.supportedMimeTypes);
 	}
 
+	/**
+	 * Allows sub-classes to add more supported mime types.
+	 * @since 5.2.2
+	 */
+	protected void addSupportedMimeTypes(MimeType... supportedMimeTypes) {
+		this.supportedMimeTypes.addAll(Arrays.asList(supportedMimeTypes));
+	}
+
 	/**
 	 * Configure the {@link ContentTypeResolver} to use to resolve the content
 	 * type of an input message.

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

@@ -22,7 +22,6 @@
 import java.io.Writer;
 import java.lang.reflect.Type;
 import java.nio.charset.Charset;
-import java.util.Arrays;
 import java.util.concurrent.atomic.AtomicReference;
 
 import com.fasterxml.jackson.annotation.JsonView;
@@ -84,7 +83,7 @@ public MappingJackson2MessageConverter() {
 	 * @since 4.1.5
 	 */
 	public MappingJackson2MessageConverter(MimeType... supportedMimeTypes) {
-		super(Arrays.asList(supportedMimeTypes));
+		super(supportedMimeTypes);
 		this.objectMapper = initObjectMapper();
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -21,7 +21,6 @@
 import java.io.StringReader;
 import java.io.StringWriter;
 import java.io.Writer;
-import java.util.Arrays;
 
 import javax.xml.transform.Result;
 import javax.xml.transform.Source;
@@ -70,7 +69,7 @@ public MarshallingMessageConverter() {
 	 * @param supportedMimeTypes the MIME types
 	 */
 	public MarshallingMessageConverter(MimeType... supportedMimeTypes) {
-		super(Arrays.asList(supportedMimeTypes));
+		super(supportedMimeTypes);
 	}
 
 	/**

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

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2002-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.messaging.converter;
+
+import com.google.protobuf.ExtensionRegistry;
+import com.google.protobuf.util.JsonFormat;
+
+import org.springframework.lang.Nullable;
+
+/**
+ * Subclass of {@link ProtobufMessageConverter} for use with the official
+ * {@code "com.google.protobuf:protobuf-java-util"} library for JSON support.
+ *
+ * <p>Most importantly, this class allows for custom JSON parser and printer
+ * configurations through the {@link JsonFormat} utility. If no special parser
+ * or printer configuration is given, default variants will be used instead.
+ *
+ * <p>Requires Protobuf 3.x and {@code "com.google.protobuf:protobuf-java-util"} 3.x,
+ * with 3.3 or higher recommended.
+ *
+ * @author Rossen Stoyanchev
+ * @since 5.2.2
+ */
+public class ProtobufJsonFormatMessageConverter extends ProtobufMessageConverter {
+
+	/**
+	 * Constructor with default instances of {@link JsonFormat.Parser},
+	 * {@link JsonFormat.Printer}, and {@link ExtensionRegistry}.
+	 */
+	public ProtobufJsonFormatMessageConverter(@Nullable ExtensionRegistry extensionRegistry) {
+		this(null, null);
+	}
+
+	/**
+	 * Constructor with given instances of {@link JsonFormat.Parser},
+	 * {@link JsonFormat.Printer}, and a default instance of {@link ExtensionRegistry}.
+	 */
+	public ProtobufJsonFormatMessageConverter(
+			@Nullable JsonFormat.Parser parser, @Nullable JsonFormat.Printer printer) {
+
+		this(parser, printer, null);
+	}
+
+	/**
+	 * Constructor with given instances of {@link JsonFormat.Parser},
+	 * {@link JsonFormat.Printer}, and {@link ExtensionRegistry}.
+	 */
+	public ProtobufJsonFormatMessageConverter(@Nullable JsonFormat.Parser parser,
+			@Nullable JsonFormat.Printer printer, @Nullable ExtensionRegistry extensionRegistry) {
+
+		super(new ProtobufJavaUtilSupport(parser, printer), extensionRegistry);
+	}
+
+}