Polishing contribution

See gh-24087

spring-messaging/spring-messaging.gradle

@@ -13,9 +13,9 @@ 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")
-	optional("com.google.protobuf:protobuf-java-util")
 	testCompile("javax.inject:javax.inject-tck")
 	testCompile("javax.servlet:javax.servlet-api")
 	testCompile("javax.validation:validation-api")

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.
@@ -17,10 +17,10 @@
 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;
-import java.util.Arrays;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -48,7 +48,7 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 
 	protected final Log logger = LogFactory.getLog(getClass());
 
-	private List<MimeType> supportedMimeTypes;
+	private final List<MimeType> supportedMimeTypes = new ArrayList<>(4);
 
 	@Nullable
 	private ContentTypeResolver contentTypeResolver = new DefaultContentTypeResolver();
@@ -59,28 +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) {
-		setSupportedMimeTypes(Collections.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(Collection<MimeType> supportedMimeTypes) {
-		setSupportedMimeTypes(new ArrayList<>(supportedMimeTypes));
+	protected AbstractMessageConverter(MimeType... supportedMimeTypes) {
+		this(Arrays.asList(supportedMimeTypes));
 	}
 
 	/**
-	 * Construct an {@code AbstractMessageConverter} supporting multiple MIME types.
+	 * Constructor with a Collection of MIME types.
 	 * @param supportedMimeTypes the supported MIME types
-	 * @since 5.2.2
 	 */
-	protected AbstractMessageConverter(MimeType... supportedMimeTypes) {
-		setSupportedMimeTypes(Arrays.asList(supportedMimeTypes));
+	protected AbstractMessageConverter(Collection<MimeType> supportedMimeTypes) {
+		this.supportedMimeTypes.addAll(supportedMimeTypes);
 	}
 
 
@@ -92,12 +92,11 @@ public List<MimeType> getSupportedMimeTypes() {
 	}
 
 	/**
-	 * Set the list of {@link MimeType} objects supported by this converter.
+	 * Allows sub-classes to add more supported mime types.
 	 * @since 5.2.2
 	 */
-	protected void setSupportedMimeTypes(List<MimeType> supportedMimeTypes) {
-		Assert.notNull(supportedMimeTypes, "supportedMimeTypes must not be null");
-		this.supportedMimeTypes = supportedMimeTypes;
+	protected void addSupportedMimeTypes(MimeType... supportedMimeTypes) {
+		this.supportedMimeTypes.addAll(Arrays.asList(supportedMimeTypes));
 	}
 
 	/**

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;

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;

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);
+	}
+
+}

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

@@ -23,12 +23,12 @@
 import java.lang.reflect.Method;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
-import java.util.Arrays;
 import java.util.Map;
 
 import com.google.protobuf.ExtensionRegistry;
 import com.google.protobuf.Message;
 import com.google.protobuf.util.JsonFormat;
+
 import org.springframework.lang.Nullable;
 import org.springframework.messaging.MessageHeaders;
 import org.springframework.util.ClassUtils;
@@ -77,59 +77,23 @@ public class ProtobufMessageConverter extends AbstractMessageConverter {
 
 
 	/**
-	 * Construct a new {@code ProtobufMessageConverter}.
+	 * Constructor with a default instance of {@link ExtensionRegistry}.
 	 */
 	public ProtobufMessageConverter() {
-		this((ProtobufFormatSupport) null, (ExtensionRegistry) null);
+		this(null, null);
 	}
 
 	/**
-	 * Construct a new {@code ProtobufMessageConverter} with a registry that specifies
-	 * protocol message extensions.
-	 *
-	 * @param extensionRegistry the registry to populate
+	 * Constructor with a given {@code ExtensionRegistry}.
 	 */
-	public ProtobufMessageConverter(@Nullable ExtensionRegistry extensionRegistry) {
+	public ProtobufMessageConverter(ExtensionRegistry extensionRegistry) {
 		this(null, extensionRegistry);
 	}
 
-	/**
-	 * Construct a new {@code ProtobufMessageConverter} with the given
-	 * {@code JsonFormat.Parser} and {@code JsonFormat.Printer} configuration.
-	 *
-	 * @param parser  the JSON parser configuration
-	 * @param printer the JSON printer configuration
-	 */
-	public ProtobufMessageConverter(@Nullable JsonFormat.Parser parser, @Nullable JsonFormat.Printer printer) {
-		this(new ProtobufJavaUtilSupport(parser, printer), (ExtensionRegistry) null);
-	}
+	ProtobufMessageConverter(@Nullable ProtobufFormatSupport formatSupport,
+			@Nullable ExtensionRegistry extensionRegistry) {
 
-	/**
-	 * Construct a new {@code ProtobufMessageConverter} with the given
-	 * {@code JsonFormat.Parser} and {@code JsonFormat.Printer} configuration, also
-	 * accepting a registry that specifies protocol message extensions.
-	 *
-	 * @param parser            the JSON parser configuration
-	 * @param printer           the JSON printer configuration
-	 * @param extensionRegistry the registry to populate
-	 */
-	public ProtobufMessageConverter(@Nullable JsonFormat.Parser parser,
-									@Nullable JsonFormat.Printer printer, @Nullable ExtensionRegistry extensionRegistry) {
-
-		this(new ProtobufJavaUtilSupport(parser, printer), extensionRegistry);
-	}
-
-	/**
-	 * Construct a new {@code ProtobufMessageConverter} with the given
-	 * {@code ProtobufFormatSupport}  configuration, also
-	 * accepting a registry that specifies protocol message extensions.
-	 *
-	 * @param formatSupport     support third party
-	 * @param extensionRegistry the registry to populate
-	 */
-	public ProtobufMessageConverter(@Nullable ProtobufFormatSupport formatSupport,
-									@Nullable ExtensionRegistry extensionRegistry) {
-		super(PROTOBUF);
+		super(PROTOBUF, TEXT_PLAIN);
 
 		if (formatSupport != null) {
 			this.protobufFormatSupport = formatSupport;
@@ -142,12 +106,13 @@ else if (ClassUtils.isPresent("com.google.protobuf.util.JsonFormat", getClass().
 		}
 
 		if (this.protobufFormatSupport != null) {
-			setSupportedMimeTypes(Arrays.asList(protobufFormatSupport.supportedMediaTypes()));
+			addSupportedMimeTypes(this.protobufFormatSupport.supportedMediaTypes());
 		}
 
 		this.extensionRegistry = (extensionRegistry == null ? ExtensionRegistry.newInstance() : extensionRegistry);
 	}
 
+
 	@Override
 	protected boolean supports(Class<?> clazz) {
 		return Message.class.isAssignableFrom(clazz);
@@ -161,7 +126,9 @@ protected boolean canConvertTo(Object payload, @Nullable MessageHeaders headers)
 	}
 
 	@Override
-	protected Object convertFromInternal(org.springframework.messaging.Message<?> message, Class<?> targetClass, @Nullable Object conversionHint) {
+	protected Object convertFromInternal(org.springframework.messaging.Message<?> message,
+			Class<?> targetClass, @Nullable Object conversionHint) {
+
 		MimeType contentType = getMimeType(message.getHeaders());
 		final Object payload = message.getPayload();
 
@@ -175,32 +142,31 @@ protected Object convertFromInternal(org.springframework.messaging.Message<?> me
 		}
 
 		Message.Builder builder = getMessageBuilder(targetClass);
-
 		try {
 			if (PROTOBUF.isCompatibleWith(contentType)) {
 				builder.mergeFrom((byte[]) payload, this.extensionRegistry);
 			}
-			else if (protobufFormatSupport != null) {
-				this.protobufFormatSupport.merge(
-						message, charset, contentType, this.extensionRegistry, builder);
+			else if (this.protobufFormatSupport != null) {
+				this.protobufFormatSupport.merge(message, charset, contentType, this.extensionRegistry, builder);
 			}
 		}
-		catch (IOException e) {
-			throw new MessageConversionException(message, "Could not read proto message" + e.getMessage(), e);
+		catch (IOException ex) {
+			throw new MessageConversionException(message, "Could not read proto message" + ex.getMessage(), ex);
 		}
 
 		return builder.build();
 	}
 
 
 	@Override
-	protected Object convertToInternal(Object payload, @Nullable MessageHeaders headers, @Nullable Object conversionHint) {
+	protected Object convertToInternal(
+			Object payload, @Nullable MessageHeaders headers, @Nullable Object conversionHint) {
+
 		final Message message = (Message) payload;
 
 		MimeType contentType = getMimeType(headers);
 		if (contentType == null) {
 			contentType = PROTOBUF;
-
 		}
 
 		Charset charset = contentType.getCharset();
@@ -220,14 +186,13 @@ else if (this.protobufFormatSupport != null) {
 				payload = new String(outputStream.toByteArray(), charset);
 			}
 		}
-		catch (IOException e) {
-			throw new MessageConversionException("Could not write proto message" + e.getMessage(), e);
+		catch (IOException ex) {
+			throw new MessageConversionException("Could not write proto message" + ex.getMessage(), ex);
 
 		}
 		return payload;
 	}
 
-
 	/**
 	 * Create a new {@code Message.Builder} instance for the given class.
 	 * <p>This method uses a ConcurrentReferenceHashMap for caching method lookups.
@@ -257,9 +222,9 @@ interface ProtobufFormatSupport {
 
 		boolean supportsWriteOnly(@Nullable MimeType mediaType);
 
-		void merge(org.springframework.messaging.Message<?> message, Charset charset, MimeType contentType,
-				   ExtensionRegistry extensionRegistry, Message.Builder builder)
-				throws IOException, MessageConversionException;
+		void merge(org.springframework.messaging.Message<?> message,
+				Charset charset, MimeType contentType, ExtensionRegistry extensionRegistry,
+				Message.Builder builder) throws IOException, MessageConversionException;
 
 		void print(Message message, OutputStream output, MimeType contentType, Charset charset)
 				throws IOException, MessageConversionException;
@@ -283,7 +248,7 @@ public ProtobufJavaUtilSupport(@Nullable JsonFormat.Parser parser, @Nullable Jso
 
 		@Override
 		public MimeType[] supportedMediaTypes() {
-			return new MimeType[]{PROTOBUF, TEXT_PLAIN, APPLICATION_JSON};
+			return new MimeType[]{APPLICATION_JSON};
 		}
 
 		@Override
@@ -292,8 +257,8 @@ public boolean supportsWriteOnly(@Nullable MimeType mimeType) {
 		}
 
 		@Override
-		public void merge(org.springframework.messaging.Message<?> message, Charset charset, MimeType contentType,
-						  ExtensionRegistry extensionRegistry, Message.Builder builder)
+		public void merge(org.springframework.messaging.Message<?> message, Charset charset,
+				MimeType contentType, ExtensionRegistry extensionRegistry, Message.Builder builder)
 				throws IOException, MessageConversionException {
 
 			if (contentType.isCompatibleWith(APPLICATION_JSON)) {
@@ -313,12 +278,12 @@ public void print(Message message, OutputStream output, MimeType contentType, Ch
 				OutputStreamWriter writer = new OutputStreamWriter(output, charset);
 				this.printer.appendTo(message, writer);
 				writer.flush();
-			} else {
+			}
+			else {
 				throw new MessageConversionException(
 						"protobuf-java-util does not support printing " + contentType);
 			}
 		}
 	}
 
-
 }