Update Google Protobuf support to 3.0.0

This commit adds support for Google Protobuf 3.0.0 and make some changes
in the additional formats support:
* "com.googlecode.protobuf-java-format:protobuf-java-format" is no
longer required and its required version has been raised to 1.3+
(this lib adds support for JSON, XML, HTML formats)
* "com.google.protobuf:protobuf-java-util" is also now supported for
JSON format

Issue: SPR-13589

build.gradle

@@ -69,6 +69,7 @@ configure(allprojects) { project ->
 	ext.okhttpVersion          = "2.7.5"
 	ext.okhttp3Version         = "3.4.1"
 	ext.poiVersion             = "3.14"
+	ext.protobufVersion        = "3.0.0-beta-4"
 	ext.reactivestreamsVersion = "1.0.0"
 	ext.reactorVersion         = "2.0.8.RELEASE"
 	ext.reactorCoreVersion     = '3.0.0.BUILD-SNAPSHOT'
@@ -734,7 +735,8 @@ project("spring-web") {
 		optional("org.eclipse.jetty:jetty-server:${jettyVersion}") {
 			exclude group: "javax.servlet", module: "javax.servlet-api"
 		}
-		optional("com.google.protobuf:protobuf-java:2.6.1")
+		optional("com.google.protobuf:protobuf-java:${protobufVersion}")
+		optional("com.google.protobuf:protobuf-java-util:${protobufVersion}")
 		optional("com.googlecode.protobuf-java-format:protobuf-java-format:1.4")
 		optional("javax.mail:javax.mail-api:${javamailVersion}")
 		testCompile(project(":spring-context-support"))  // for JafMediaTypeFactory

spring-web/src/main/java/org/springframework/http/converter/protobuf/ProtobufHttpMessageConverter.java

@@ -17,20 +17,21 @@
 package org.springframework.http.converter.protobuf;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.lang.reflect.Method;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.concurrent.ConcurrentHashMap;
 
+import com.google.protobuf.CodedOutputStream;
 import com.google.protobuf.ExtensionRegistry;
 import com.google.protobuf.Message;
 import com.google.protobuf.TextFormat;
-import com.googlecode.protobuf.format.HtmlFormat;
-import com.googlecode.protobuf.format.JsonFormat;
+import com.googlecode.protobuf.format.FormatFactory;
 import com.googlecode.protobuf.format.ProtobufFormatter;
-import com.googlecode.protobuf.format.XmlFormat;
 
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
@@ -38,18 +39,28 @@ import org.springframework.http.MediaType;
 import org.springframework.http.converter.AbstractHttpMessageConverter;
 import org.springframework.http.converter.HttpMessageNotReadableException;
 import org.springframework.http.converter.HttpMessageNotWritableException;
-import org.springframework.util.FileCopyUtils;
+import org.springframework.util.ClassUtils;
 
 /**
  * An {@code HttpMessageConverter} that reads and writes {@link com.google.protobuf.Message}s
  * using <a href="https://developers.google.com/protocol-buffers/">Google Protocol Buffers</a>.
  *
- * <p>By default, it supports {@code "application/x-protobuf"}, {@code "text/plain"},
- * {@code "application/json"}, {@code "application/xml"}, while also writing {@code "text/html"}.
+ * <p>This converter supports by default {@code "application/x-protobuf"} and {@code "text/plain"}
+ * with the official {@code "com.google.protobuf:protobuf-java"} library.
+ *
+ * <p>Other formats can be supported with additional libraries:
+ * <ul>
+ *     <li>{@code "application/json"} with the official library
+ *     {@code "com.google.protobuf:protobuf-java-util"}
+ *     <li>{@code "application/json"}, {@code "application/xml"} and {@code "text/html"} (write only)
+ *     can be supported with the 3rd party library
+ *     {@code "com.googlecode.protobuf-java-format:protobuf-java-format"}
+ * </ul>
  *
  * <p>To generate {@code Message} Java classes, you need to install the {@code protoc} binary.
  *
  * <p>Requires Protobuf 2.6 and Protobuf Java Format 1.4, as of Spring 4.3.
+ * Supports up to Protobuf 3.0.0.
  *
  * @author Alex Antonov
  * @author Brian Clozel
@@ -66,18 +77,32 @@ public class ProtobufHttpMessageConverter extends AbstractHttpMessageConverter<M
 
 	public static final String X_PROTOBUF_MESSAGE_HEADER = "X-Protobuf-Message";
 
+	private static final boolean isProtobufJavaUtilPresent =
+			ClassUtils.isPresent("com.google.protobuf.util.JsonFormat", ProtobufHttpMessageConverter.class.getClassLoader());
 
-	private static final ProtobufFormatter JSON_FORMAT = new JsonFormat();
-
-	private static final ProtobufFormatter XML_FORMAT = new XmlFormat();
+	private static final boolean isProtobufJavaFormatPresent =
+			ClassUtils.isPresent("com.googlecode.protobuf.format.JsonFormat", ProtobufHttpMessageConverter.class.getClassLoader());
 
-	private static final ProtobufFormatter HTML_FORMAT = new HtmlFormat();
+	private static final MediaType[] SUPPORTED_MEDIATYPES;
 
+	private final ProtobufFormatsSupport protobufFormatsSupport;
 
 	private static final ConcurrentHashMap<Class<?>, Method> methodCache = new ConcurrentHashMap<>();
 
 	private final ExtensionRegistry extensionRegistry = ExtensionRegistry.newInstance();
 
+	static {
+		if (isProtobufJavaFormatPresent) {
+			SUPPORTED_MEDIATYPES = new MediaType[] {PROTOBUF, MediaType.TEXT_PLAIN, MediaType.APPLICATION_XML,
+					MediaType.APPLICATION_JSON};
+		}
+		else if (isProtobufJavaUtilPresent) {
+			SUPPORTED_MEDIATYPES = new MediaType[] {PROTOBUF, MediaType.TEXT_PLAIN, MediaType.APPLICATION_JSON};
+		}
+		else {
+			SUPPORTED_MEDIATYPES = new MediaType[] {PROTOBUF, MediaType.TEXT_PLAIN};
+		}
+	}
 
 	/**
 	 * Construct a new instance.
@@ -91,7 +116,16 @@ public class ProtobufHttpMessageConverter extends AbstractHttpMessageConverter<M
 	 * that allows the registration of message extensions.
 	 */
 	public ProtobufHttpMessageConverter(ExtensionRegistryInitializer registryInitializer) {
-		super(PROTOBUF, MediaType.TEXT_PLAIN, MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML);
+		super(SUPPORTED_MEDIATYPES);
+		if (isProtobufJavaFormatPresent) {
+			this.protobufFormatsSupport = new ProtobufJavaFormatSupport();
+		}
+		else if (isProtobufJavaUtilPresent) {
+			this.protobufFormatsSupport = new ProtobufJavaUtilSupport();
+		}
+		else {
+			this.protobufFormatsSupport = null;
+		}
 		if (registryInitializer != null) {
 			registryInitializer.initializeExtensionRegistry(this.extensionRegistry);
 		}
@@ -123,18 +157,16 @@ public class ProtobufHttpMessageConverter extends AbstractHttpMessageConverter<M
 
 		try {
 			Message.Builder builder = getMessageBuilder(clazz);
-			if (MediaType.TEXT_PLAIN.isCompatibleWith(contentType)) {
+			if (PROTOBUF.isCompatibleWith(contentType)) {
+				builder.mergeFrom(inputMessage.getBody(), this.extensionRegistry);
+			}
+			else if (MediaType.TEXT_PLAIN.isCompatibleWith(contentType)) {
 				InputStreamReader reader = new InputStreamReader(inputMessage.getBody(), charset);
 				TextFormat.merge(reader, this.extensionRegistry, builder);
 			}
-			else if (MediaType.APPLICATION_JSON.isCompatibleWith(contentType)) {
-				JSON_FORMAT.merge(inputMessage.getBody(), charset, this.extensionRegistry, builder);
-			}
-			else if (MediaType.APPLICATION_XML.isCompatibleWith(contentType)) {
-				XML_FORMAT.merge(inputMessage.getBody(), charset, this.extensionRegistry, builder);
-			}
-			else {
-				builder.mergeFrom(inputMessage.getBody(), this.extensionRegistry);
+			else if (isProtobufJavaUtilPresent || isProtobufJavaFormatPresent) {
+				this.protobufFormatsSupport.merge(inputMessage.getBody(), charset, contentType,
+						this.extensionRegistry, builder);
 			}
 			return builder.build();
 		}
@@ -149,7 +181,8 @@ public class ProtobufHttpMessageConverter extends AbstractHttpMessageConverter<M
 	 */
 	@Override
 	protected boolean canWrite(MediaType mediaType) {
-		return (super.canWrite(mediaType) || MediaType.TEXT_HTML.isCompatibleWith(mediaType));
+		return (super.canWrite(mediaType) ||
+				(isProtobufJavaFormatPresent && MediaType.TEXT_HTML.isCompatibleWith(mediaType)));
 	}
 
 	@Override
@@ -165,23 +198,21 @@ public class ProtobufHttpMessageConverter extends AbstractHttpMessageConverter<M
 			charset = DEFAULT_CHARSET;
 		}
 
-		if (MediaType.TEXT_PLAIN.isCompatibleWith(contentType)) {
-			OutputStreamWriter outputStreamWriter = new OutputStreamWriter(outputMessage.getBody(), charset);
+		if (PROTOBUF.isCompatibleWith(contentType)) {
+			setProtoHeader(outputMessage, message);
+			CodedOutputStream codedOutputStream = CodedOutputStream.newInstance(outputMessage.getBody());
+			message.writeTo(codedOutputStream);
+			codedOutputStream.flush();
+		}
+		else if (MediaType.TEXT_PLAIN.isCompatibleWith(contentType)) {
+			final OutputStreamWriter outputStreamWriter = new OutputStreamWriter(outputMessage.getBody(), charset);
 			TextFormat.print(message, outputStreamWriter);
 			outputStreamWriter.flush();
+			outputMessage.getBody().flush();
 		}
-		else if (MediaType.APPLICATION_JSON.isCompatibleWith(contentType)) {
-			JSON_FORMAT.print(message, outputMessage.getBody(), charset);
-		}
-		else if (MediaType.APPLICATION_XML.isCompatibleWith(contentType)) {
-			XML_FORMAT.print(message, outputMessage.getBody(), charset);
-		}
-		else if (MediaType.TEXT_HTML.isCompatibleWith(contentType)) {
-			HTML_FORMAT.print(message, outputMessage.getBody(), charset);
-		}
-		else if (PROTOBUF.isCompatibleWith(contentType)) {
-			setProtoHeader(outputMessage, message);
-			FileCopyUtils.copy(message.toByteArray(), outputMessage.getBody());
+		else if (isProtobufJavaUtilPresent || isProtobufJavaFormatPresent) {
+			this.protobufFormatsSupport.print(message, outputMessage.getBody(), contentType, charset);
+			outputMessage.getBody().flush();
 		}
 	}
 
@@ -210,4 +241,100 @@ public class ProtobufHttpMessageConverter extends AbstractHttpMessageConverter<M
 		return (Message.Builder) method.invoke(clazz);
 	}
 
+	private interface ProtobufFormatsSupport {
+
+		void merge(InputStream input, Charset cs, MediaType contentType, ExtensionRegistry extensionRegistry,
+				Message.Builder builder) throws IOException;
+
+		void print(Message message, OutputStream output, MediaType contentType, Charset cs) throws IOException;
+	}
+
+	private class ProtobufJavaUtilSupport implements ProtobufFormatsSupport {
+
+		private final com.google.protobuf.util.JsonFormat.Parser parser;
+
+		private final com.google.protobuf.util.JsonFormat.Printer printer;
+
+		public ProtobufJavaUtilSupport() {
+			this.parser = com.google.protobuf.util.JsonFormat.parser();
+			this.printer = com.google.protobuf.util.JsonFormat.printer();
+		}
+
+		@Override
+		public void merge(InputStream input, Charset cs, MediaType contentType,
+				ExtensionRegistry extensionRegistry, Message.Builder builder) throws IOException {
+
+			if (contentType.isCompatibleWith(MediaType.APPLICATION_JSON)) {
+				InputStreamReader reader = new InputStreamReader(input, cs);
+				this.parser.merge(reader, builder);
+			}
+			else {
+				throw new UnsupportedOperationException("com.googlecode.protobuf:protobuf-java-util does not support "
+						+ contentType.toString() + " format");
+			}
+		}
+
+		@Override
+		public void print(Message message, OutputStream output, MediaType contentType, Charset cs) throws IOException {
+			if (contentType.isCompatibleWith(MediaType.APPLICATION_JSON)) {
+				this.printer.appendTo(message, new OutputStreamWriter(output, cs));
+			}
+			else {
+				throw new UnsupportedOperationException("com.googlecode.protobuf:protobuf-java-util does not support "
+						+ contentType.toString() + " format");
+			}
+		}
+
+	}
+
+	private class ProtobufJavaFormatSupport implements ProtobufFormatsSupport {
+
+		private final FormatFactory FORMAT_FACTORY;
+
+		private final ProtobufFormatter JSON_FORMATTER;
+
+		private final ProtobufFormatter XML_FORMATTER;
+
+		private final ProtobufFormatter HTML_FORMATTER;
+
+		public ProtobufJavaFormatSupport() {
+			FORMAT_FACTORY = new FormatFactory();
+			JSON_FORMATTER = FORMAT_FACTORY.createFormatter(FormatFactory.Formatter.JSON);
+			XML_FORMATTER = FORMAT_FACTORY.createFormatter(FormatFactory.Formatter.XML);
+			HTML_FORMATTER = FORMAT_FACTORY.createFormatter(FormatFactory.Formatter.HTML);
+		}
+
+		@Override
+		public void merge(InputStream input, Charset cs, MediaType contentType,
+				ExtensionRegistry extensionRegistry, Message.Builder builder) throws IOException {
+			if (contentType.isCompatibleWith(MediaType.APPLICATION_JSON)) {
+				JSON_FORMATTER.merge(input, cs, extensionRegistry, builder);
+			}
+			else if (contentType.isCompatibleWith(MediaType.APPLICATION_XML)) {
+				XML_FORMATTER.merge(input, cs, extensionRegistry, builder);
+			}
+			else {
+				throw new UnsupportedOperationException("com.google.protobuf.util does not support "
+						+ contentType.toString() + " format");
+			}
+		}
+
+		@Override
+		public void print(Message message, OutputStream output, MediaType contentType, Charset cs) throws IOException {
+			if (contentType.isCompatibleWith(MediaType.APPLICATION_JSON)) {
+				JSON_FORMATTER.print(message, output, cs);
+			}
+			else if (contentType.isCompatibleWith(MediaType.APPLICATION_XML)) {
+				XML_FORMATTER.print(message, output, cs);
+			}
+			else if (contentType.isCompatibleWith(MediaType.TEXT_HTML)) {
+				HTML_FORMATTER.print(message, output, cs);
+			}
+			else {
+				throw new UnsupportedOperationException("com.google.protobuf.util does not support "
+						+ contentType.toString() + " format");
+			}
+		}
+	}
+
 }