Remove support for Protobuf 2.x and protobuf-java-format

Closes gh-31465

framework-platform/framework-platform.gradle

@@ -30,8 +30,7 @@ dependencies {
 		api("com.google.code.findbugs:findbugs:3.0.1")
 		api("com.google.code.findbugs:jsr305:3.0.2")
 		api("com.google.code.gson:gson:2.10.1")
-		api("com.google.protobuf:protobuf-java-util:3.23.2")
-		api("com.googlecode.protobuf-java-format:protobuf-java-format:1.4")
+		api("com.google.protobuf:protobuf-java-util:3.24.4")
 		api("com.h2database:h2:2.2.220")
 		api("com.jayway.jsonpath:json-path:2.8.0")
 		api("com.rometools:rome:1.19.0")

spring-web/spring-web.gradle

@@ -18,7 +18,6 @@ dependencies {
 	optional("com.fasterxml.woodstox:woodstox-core")
 	optional("com.google.code.gson:gson")
 	optional("com.google.protobuf:protobuf-java-util")
-	optional("com.googlecode.protobuf-java-format:protobuf-java-format")
 	optional("com.rometools:rome")
 	optional("com.squareup.okhttp3:okhttp")
 	optional("io.reactivex.rxjava3:rxjava")

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -32,8 +32,6 @@ import com.google.protobuf.ExtensionRegistry;
 import com.google.protobuf.Message;
 import com.google.protobuf.TextFormat;
 import com.google.protobuf.util.JsonFormat;
-import com.googlecode.protobuf.format.FormatFactory;
-import com.googlecode.protobuf.format.ProtobufFormatter;
 
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
@@ -48,8 +46,6 @@ import org.springframework.util.ClassUtils;
 import org.springframework.util.ConcurrentReferenceHashMap;
 
 import static org.springframework.http.MediaType.APPLICATION_JSON;
-import static org.springframework.http.MediaType.APPLICATION_XML;
-import static org.springframework.http.MediaType.TEXT_HTML;
 import static org.springframework.http.MediaType.TEXT_PLAIN;
 
 /**
@@ -60,26 +56,17 @@ import static org.springframework.http.MediaType.TEXT_PLAIN;
  * <p>To generate {@code Message} Java classes, you need to install the {@code protoc} binary.
  *
  * <p>This converter supports by default {@code "application/x-protobuf"} and {@code "text/plain"}
- * with the official {@code "com.google.protobuf:protobuf-java"} library. Other formats can be
- * supported with one of the following additional libraries on the classpath:
- * <ul>
- * <li>{@code "application/json"}, {@code "application/xml"}, and {@code "text/html"} (write-only)
- * with the {@code "com.googlecode.protobuf-java-format:protobuf-java-format"} third-party library
- * <li>{@code "application/json"} with the official {@code "com.google.protobuf:protobuf-java-util"}
- * for Protobuf 3 (see {@link ProtobufJsonFormatHttpMessageConverter} for a configurable variant)
- * </ul>
+ * with the official {@code "com.google.protobuf:protobuf-java"} library.
+ * The {@code "application/json"} format is also supported with the {@code "com.google.protobuf:protobuf-java-util"}
+ * dependency. See {@link ProtobufJsonFormatHttpMessageConverter} for a configurable variant.
  *
- * <p>Requires Protobuf 2.6 or higher (and Protobuf Java Format 1.4 or higher for formatting).
- * This converter will auto-adapt to Protobuf 3 and its default {@code protobuf-java-util} JSON
- * format if the Protobuf 2 based {@code protobuf-java-format} isn't present; however, for more
- * explicit JSON setup on Protobuf 3, consider {@link ProtobufJsonFormatHttpMessageConverter}.
+ * <p>This converter requires Protobuf 3 or higher as of Spring Framework 6.1.
  *
  * @author Alex Antonov
  * @author Brian Clozel
  * @author Juergen Hoeller
  * @author Sebastien Deleuze
  * @since 4.1
- * @see FormatFactory
  * @see JsonFormat
  * @see ProtobufJsonFormatHttpMessageConverter
  */
@@ -105,18 +92,10 @@ public class ProtobufHttpMessageConverter extends AbstractHttpMessageConverter<M
 	 */
 	public static final String X_PROTOBUF_MESSAGE_HEADER = "X-Protobuf-Message";
 
-	private static final boolean protobufFormatFactoryPresent;
-
-	private static final boolean protobufJsonFormatPresent;
+	private static final boolean protobufJsonFormatPresent = ClassUtils.isPresent("com.google.protobuf.util.JsonFormat", ProtobufHttpMessageConverter.class.getClassLoader());
 
 	private static final Map<Class<?>, Method> methodCache = new ConcurrentReferenceHashMap<>();
 
-	static {
-		ClassLoader classLoader = ProtobufHttpMessageConverter.class.getClassLoader();
-		protobufFormatFactoryPresent = ClassUtils.isPresent("com.googlecode.protobuf.format.FormatFactory", classLoader);
-		protobufJsonFormatPresent = ClassUtils.isPresent("com.google.protobuf.util.JsonFormat", classLoader);
-	}
-
 
 	final ExtensionRegistry extensionRegistry;
 
@@ -146,9 +125,6 @@ public class ProtobufHttpMessageConverter extends AbstractHttpMessageConverter<M
 		if (formatSupport != null) {
 			this.protobufFormatSupport = formatSupport;
 		}
-		else if (protobufFormatFactoryPresent) {
-			this.protobufFormatSupport = new ProtobufJavaFormatSupport();
-		}
 		else if (protobufJsonFormatPresent) {
 			this.protobufFormatSupport = new ProtobufJavaUtilSupport(null, null);
 		}
@@ -290,73 +266,6 @@ public class ProtobufHttpMessageConverter extends AbstractHttpMessageConverter<M
 	}
 
 
-	/**
-	 * {@link ProtobufFormatSupport} implementation used when
-	 * {@code com.googlecode.protobuf.format.FormatFactory} is available.
-	 */
-	static class ProtobufJavaFormatSupport implements ProtobufFormatSupport {
-
-		private final ProtobufFormatter jsonFormatter;
-
-		private final ProtobufFormatter xmlFormatter;
-
-		private final ProtobufFormatter htmlFormatter;
-
-		public ProtobufJavaFormatSupport() {
-			FormatFactory formatFactory = new FormatFactory();
-			this.jsonFormatter = formatFactory.createFormatter(FormatFactory.Formatter.JSON);
-			this.xmlFormatter = formatFactory.createFormatter(FormatFactory.Formatter.XML);
-			this.htmlFormatter = formatFactory.createFormatter(FormatFactory.Formatter.HTML);
-		}
-
-		@Override
-		public MediaType[] supportedMediaTypes() {
-			return new MediaType[] {PROTOBUF, TEXT_PLAIN, APPLICATION_XML, APPLICATION_JSON};
-		}
-
-		@Override
-		public boolean supportsWriteOnly(@Nullable MediaType mediaType) {
-			return TEXT_HTML.isCompatibleWith(mediaType);
-		}
-
-		@Override
-		public void merge(InputStream input, Charset charset, MediaType contentType,
-				ExtensionRegistry extensionRegistry, Message.Builder builder)
-				throws IOException, HttpMessageConversionException {
-
-			if (contentType.isCompatibleWith(APPLICATION_JSON)) {
-				this.jsonFormatter.merge(input, charset, extensionRegistry, builder);
-			}
-			else if (contentType.isCompatibleWith(APPLICATION_XML)) {
-				this.xmlFormatter.merge(input, charset, extensionRegistry, builder);
-			}
-			else {
-				throw new HttpMessageConversionException(
-						"protobuf-java-format does not support parsing " + contentType);
-			}
-		}
-
-		@Override
-		public void print(Message message, OutputStream output, MediaType contentType, Charset charset)
-				throws IOException, HttpMessageConversionException {
-
-			if (contentType.isCompatibleWith(APPLICATION_JSON)) {
-				this.jsonFormatter.print(message, output, charset);
-			}
-			else if (contentType.isCompatibleWith(APPLICATION_XML)) {
-				this.xmlFormatter.print(message, output, charset);
-			}
-			else if (contentType.isCompatibleWith(TEXT_HTML)) {
-				this.htmlFormatter.print(message, output, charset);
-			}
-			else {
-				throw new HttpMessageConversionException(
-						"protobuf-java-format does not support printing " + contentType);
-			}
-		}
-	}
-
-
 	/**
 	 * {@link ProtobufFormatSupport} implementation used when
 	 * {@code com.google.protobuf.util.JsonFormat} is available.

spring-web/src/test/java/org/springframework/http/converter/protobuf/ProtobufHttpMessageConverterTests.java

@@ -55,11 +55,7 @@ class ProtobufHttpMessageConverterTests {
 		assertThat(this.converter.canRead(Msg.class, null)).isTrue();
 		assertThat(this.converter.canRead(Msg.class, ProtobufHttpMessageConverter.PROTOBUF)).isTrue();
 		assertThat(this.converter.canRead(Msg.class, MediaType.APPLICATION_JSON)).isTrue();
-		assertThat(this.converter.canRead(Msg.class, MediaType.APPLICATION_XML)).isTrue();
 		assertThat(this.converter.canRead(Msg.class, MediaType.TEXT_PLAIN)).isTrue();
-
-		// only supported as an output format
-		assertThat(this.converter.canRead(Msg.class, MediaType.TEXT_HTML)).isFalse();
 	}
 
 	@Test
@@ -67,9 +63,7 @@ class ProtobufHttpMessageConverterTests {
 		assertThat(this.converter.canWrite(Msg.class, null)).isTrue();
 		assertThat(this.converter.canWrite(Msg.class, ProtobufHttpMessageConverter.PROTOBUF)).isTrue();
 		assertThat(this.converter.canWrite(Msg.class, MediaType.APPLICATION_JSON)).isTrue();
-		assertThat(this.converter.canWrite(Msg.class, MediaType.APPLICATION_XML)).isTrue();
 		assertThat(this.converter.canWrite(Msg.class, MediaType.TEXT_PLAIN)).isTrue();
-		assertThat(this.converter.canWrite(Msg.class, MediaType.TEXT_HTML)).isTrue();
 	}
 
 	@Test
@@ -131,31 +125,6 @@ class ProtobufHttpMessageConverterTests {
 				ProtobufHttpMessageConverter.X_PROTOBUF_SCHEMA_HEADER)).isNull();
 	}
 
-	@Test
-	void writeJsonWithJavaFormat() throws IOException {
-		this.converter = new ProtobufHttpMessageConverter(
-				new ProtobufHttpMessageConverter.ProtobufJavaFormatSupport(),
-				this.extensionRegistry);
-		MockHttpOutputMessage outputMessage = new MockHttpOutputMessage();
-		@SuppressWarnings("deprecation")
-		MediaType contentType = MediaType.APPLICATION_JSON_UTF8;
-		this.converter.write(this.testMsg, contentType, outputMessage);
-
-		assertThat(outputMessage.getHeaders().getContentType()).isEqualTo(contentType);
-
-		String body = outputMessage.getBodyAsString(StandardCharsets.UTF_8);
-		assertThat(body).as("body is empty").isNotEmpty();
-
-		Msg.Builder builder = Msg.newBuilder();
-		JsonFormat.parser().merge(body, builder);
-		assertThat(builder.build()).isEqualTo(this.testMsg);
-
-		assertThat(outputMessage.getHeaders().getFirst(
-				ProtobufHttpMessageConverter.X_PROTOBUF_MESSAGE_HEADER)).isNull();
-		assertThat(outputMessage.getHeaders().getFirst(
-				ProtobufHttpMessageConverter.X_PROTOBUF_SCHEMA_HEADER)).isNull();
-	}
-
 	@Test
 	void defaultContentType() throws Exception {
 		assertThat(this.converter.getDefaultContentType(this.testMsg))