Use Google libraries for JSON processing in gRPC

docs/modules/ROOT/pages/spring-cloud-gateway-server-webflux/gatewayfilter-factories/jsontogrpc-factory.adoc

@@ -5,6 +5,10 @@ The JSONToGRPC GatewayFilter Factory converts a JSON payload to a gRPC request.
 
 The filter takes the following arguments:
 
+* `service`: Short name of the service that handles the request.
+
+* `method`: Method name in the service that handles the request.
+
 * `protoDescriptor`: Proto descriptor file.
 
 This file can be generated using `protoc` and specifying the `--descriptor_set_out` flag:
@@ -16,12 +20,6 @@ protoc --proto_path=src/main/resources/proto/ \
 src/main/resources/proto/hello.proto
 ----
 
-* `protoFile`: Proto definition file.
-
-* `service`: Short name of the service that handles the request.
-
-* `method`: Method name in the service that handles the request.
-
 NOTE: `streaming` is not supported.
 
 
@@ -33,11 +31,10 @@ NOTE: `streaming` is not supported.
 public RouteLocator routes(RouteLocatorBuilder builder) {
     return builder.routes()
             .route("json-grpc", r -> r.path("/json/hello").filters(f -> {
-                String protoDescriptor = "file:src/main/proto/hello.pb";
-                String protoFile = "file:src/main/proto/hello.proto";
                 String service = "HelloService";
                 String method = "hello";
-                return f.jsonToGRPC(protoDescriptor, protoFile, service, method);
+                String protoDescriptor = "file:src/main/proto/hello.pb";
+                return f.jsonToGRPC(service, method, protoDescriptor);
             }).uri(uri))
 ----
 
@@ -48,17 +45,15 @@ spring:
     gateway:
       routes:
         - id: json-grpc
-          uri: https://localhost:6565/testhello
+          uri: https://localhost:6565
           predicates:
             - Path=/json/**
           filters:
             - name: JsonToGrpc
               args:
-                protoDescriptor: file:proto/hello.pb
-                protoFile: file:proto/hello.proto
                 service: HelloService
                 method: hello
-
+                protoDescriptor: file:proto/hello.pb
 ----
 
 When a request is made through the gateway to `/json/hello`, the request is transformed by using the definition provided in `hello.proto`, sent to `HelloService/hello`, and the response back is transformed to JSON.

spring-cloud-gateway-integration-tests/grpc/pom.xml

@@ -12,6 +12,7 @@
 
 	<properties>
 		<protoc.version>3.25.1</protoc.version>
+		<protobuf.version>4.31.1</protobuf.version>
 		<grpc.version>1.72.0</grpc.version>
 	</properties>
 
@@ -45,15 +46,16 @@
 			<artifactId>grpc-protobuf</artifactId>
 			<version>${grpc.version}</version>
 		</dependency>
+		<dependency>
+			<groupId>com.google.protobuf</groupId>
+			<artifactId>protobuf-java-util</artifactId>
+			<version>${protobuf.version}</version>
+		</dependency>
 		<dependency>
 			<groupId>io.grpc</groupId>
 			<artifactId>grpc-stub</artifactId>
 			<version>${grpc.version}</version>
 		</dependency>
-		<dependency>
-			<groupId>com.fasterxml.jackson.dataformat</groupId>
-			<artifactId>jackson-dataformat-protobuf</artifactId>
-		</dependency>
 		<dependency>
 			<groupId>com.fasterxml.jackson.core</groupId>
 			<artifactId>jackson-databind</artifactId>
@@ -129,4 +131,3 @@
 		</plugins>
 	</build>
 </project>
-

spring-cloud-gateway-integration-tests/grpc/src/test/java/org/springframework/cloud/gateway/tests/grpc/GRPCApplicationTests.java

@@ -31,17 +31,19 @@
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
 import org.springframework.boot.web.server.test.LocalServerPort;
+import org.springframework.test.annotation.DirtiesContext;
 
 import static io.grpc.Status.FAILED_PRECONDITION;
 import static io.grpc.netty.NegotiationType.TLS;
-import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
 
 /**
  * @author Alberto C. Ríos
  */
 @SpringBootTest(classes = org.springframework.cloud.gateway.tests.grpc.GRPCApplication.class,
 		webEnvironment = WebEnvironment.RANDOM_PORT)
+@DirtiesContext
 public class GRPCApplicationTests {
 
 	@LocalServerPort

spring-cloud-gateway-integration-tests/grpc/src/test/java/org/springframework/cloud/gateway/tests/grpc/JsonToGrpcApplicationTests.java

@@ -36,22 +36,21 @@
 import org.apache.hc.core5.ssl.TrustStrategy;
 import org.assertj.core.api.Assertions;
 import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
 import org.springframework.boot.web.server.test.LocalServerPort;
 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
+import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.web.client.RestTemplate;
 
-import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
-
 /**
  * @author Alberto C. Ríos
  * @author Abel Salgado Romero
  */
-@Disabled
 @SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+@DirtiesContext
 public class JsonToGrpcApplicationTests {
 
 	@LocalServerPort
@@ -72,7 +71,7 @@ public void shouldConvertFromJSONToGRPC() {
 		final RouteConfigurer configurer = new RouteConfigurer(gatewayPort);
 		int grpcServerPort = gatewayPort + 1;
 		configurer.addRoute(grpcServerPort, "/json/hello",
-				"JsonToGrpc=file:src/main/proto/hello.pb,file:src/main/proto/hello.proto,HelloService,hello");
+				"JsonToGrpc=HelloService,hello,file:src/main/proto/hello.pb");
 
 		String response = restTemplate
 			.postForEntity("https://localhost:" + this.gatewayPort + "/json/hello",

spring-cloud-gateway-integration-tests/grpc/src/test/resources/application.yml

@@ -10,7 +10,7 @@ server:
 management:
   endpoint:
     health:
-      show-details: when_authorized
+      show-details: when-authorized
     gateway:
       enabled: true
   endpoints:

spring-cloud-gateway-server/pom.xml

@@ -17,6 +17,7 @@
 	<properties>
 		<main.basedir>${basedir}/..</main.basedir>
 		<grpc.version>1.72.0</grpc.version>
+		<protobuf.version>4.31.1</protobuf.version>
 		<context-propagation.version>1.0.0</context-propagation.version>
 	</properties>
 
@@ -103,11 +104,6 @@
 			<artifactId>reactor-kotlin-extensions</artifactId>
 			<optional>true</optional>
 		</dependency>
-		<dependency>
-			<groupId>com.fasterxml.jackson.dataformat</groupId>
-			<artifactId>jackson-dataformat-protobuf</artifactId>
-			<optional>true</optional>
-		</dependency>
 		<dependency>
 			<groupId>com.fasterxml.jackson.core</groupId>
 			<artifactId>jackson-databind</artifactId>
@@ -125,6 +121,12 @@
 			<optional>true</optional>
 			<version>${grpc.version}</version>
 		</dependency>
+		<dependency>
+			<groupId>com.google.protobuf</groupId>
+			<artifactId>protobuf-java-util</artifactId>
+			<optional>true</optional>
+			<version>${protobuf.version}</version>
+		</dependency>
 		<dependency>
 			<groupId>io.grpc</groupId>
 			<artifactId>grpc-stub</artifactId>

spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/factory/JsonToGrpcGatewayFilterFactory.java

@@ -17,7 +17,6 @@
 package org.springframework.cloud.gateway.filter.factory;
 
 import java.io.IOException;
-import java.io.InputStream;
 import java.net.URI;
 import java.util.Arrays;
 import java.util.List;
@@ -31,15 +30,17 @@
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.ObjectReader;
-import com.fasterxml.jackson.databind.ObjectWriter;
 import com.fasterxml.jackson.databind.SerializationFeature;
 import com.fasterxml.jackson.databind.node.ObjectNode;
-import com.fasterxml.jackson.dataformat.protobuf.ProtobufFactory;
-import com.fasterxml.jackson.dataformat.protobuf.schema.ProtobufSchema;
-import com.fasterxml.jackson.dataformat.protobuf.schema.ProtobufSchemaLoader;
 import com.google.protobuf.DescriptorProtos;
+import com.google.protobuf.DescriptorProtos.FileDescriptorProto;
+import com.google.protobuf.DescriptorProtos.FileDescriptorSet;
 import com.google.protobuf.Descriptors;
+import com.google.protobuf.Descriptors.DescriptorValidationException;
+import com.google.protobuf.Descriptors.FileDescriptor;
 import com.google.protobuf.DynamicMessage;
+import com.google.protobuf.ProtocolStringList;
+import com.google.protobuf.util.JsonFormat;
 import io.grpc.CallOptions;
 import io.grpc.Channel;
 import io.grpc.ClientCall;
@@ -95,7 +96,7 @@ public JsonToGrpcGatewayFilterFactory(GrpcSslConfigurer grpcSslConfigurer, Resou
 
 	@Override
 	public List<String> shortcutFieldOrder() {
-		return Arrays.asList("protoDescriptor", "protoFile", "service", "method");
+		return Arrays.asList("service", "method", "protoDescriptor");
 	}
 
 	@Override
@@ -124,8 +125,6 @@ public static class Config {
 
 		private String protoDescriptor;
 
-		private String protoFile;
-
 		private String service;
 
 		private String method;
@@ -139,15 +138,6 @@ public Config setProtoDescriptor(String protoDescriptor) {
 			return this;
 		}
 
-		public String getProtoFile() {
-			return protoFile;
-		}
-
-		public Config setProtoFile(String protoFile) {
-			this.protoFile = protoFile;
-			return this;
-		}
-
 		public String getService() {
 			return service;
 		}
@@ -174,8 +164,6 @@ class GRPCResponseDecorator extends ServerHttpResponseDecorator {
 
 		private final Descriptors.Descriptor descriptor;
 
-		private final ObjectWriter objectWriter;
-
 		private final ObjectReader objectReader;
 
 		private final ClientCall<DynamicMessage, DynamicMessage> clientCall;
@@ -186,26 +174,16 @@ class GRPCResponseDecorator extends ServerHttpResponseDecorator {
 			super(exchange.getResponse());
 			this.exchange = exchange;
 			try {
-				Resource descriptorFile = resourceLoader.getResource(config.getProtoDescriptor());
-				Resource protoFile = resourceLoader.getResource(config.getProtoFile());
-
-				descriptor = DescriptorProtos.FileDescriptorProto.parseFrom(descriptorFile.getInputStream())
-					.getDescriptorForType();
-
-				Descriptors.MethodDescriptor methodDescriptor = getMethodDescriptor(config,
-						descriptorFile.getInputStream());
+				Descriptors.MethodDescriptor methodDescriptor = getMethodDescriptor(config);
 				Descriptors.ServiceDescriptor serviceDescriptor = methodDescriptor.getService();
 				Descriptors.Descriptor outputType = methodDescriptor.getOutputType();
+				this.descriptor = methodDescriptor.getInputType();
 
 				clientCall = createClientCallForType(config, serviceDescriptor, outputType);
 
-				ProtobufSchema schema = ProtobufSchemaLoader.std.load(protoFile.getInputStream());
-				ProtobufSchema responseType = schema.withRootType(outputType.getName());
-
-				ObjectMapper objectMapper = new ObjectMapper(new ProtobufFactory());
+				ObjectMapper objectMapper = new ObjectMapper();
 				objectMapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
-				objectWriter = objectMapper.writer(schema);
-				objectReader = objectMapper.readerFor(JsonNode.class).with(responseType);
+				objectReader = objectMapper.readerFor(JsonNode.class);
 				objectNode = objectMapper.createObjectNode();
 
 			}
@@ -241,13 +219,14 @@ private ClientCall<DynamicMessage, DynamicMessage> createClientCallForType(Confi
 			return channel.newCall(methodDescriptor, CallOptions.DEFAULT);
 		}
 
-		private Descriptors.MethodDescriptor getMethodDescriptor(Config config, InputStream descriptorFile)
+		private Descriptors.MethodDescriptor getMethodDescriptor(Config config)
 				throws IOException, Descriptors.DescriptorValidationException {
+			Resource descriptorFile = resourceLoader.getResource(config.getProtoDescriptor());
 			DescriptorProtos.FileDescriptorSet fileDescriptorSet = DescriptorProtos.FileDescriptorSet
-				.parseFrom(descriptorFile);
+				.parseFrom(descriptorFile.getInputStream());
 			DescriptorProtos.FileDescriptorProto fileProto = fileDescriptorSet.getFile(0);
 			Descriptors.FileDescriptor fileDescriptor = Descriptors.FileDescriptor.buildFrom(fileProto,
-					new Descriptors.FileDescriptor[0]);
+					dependencies(fileDescriptorSet, fileProto.getDependencyList()));
 
 			Descriptors.ServiceDescriptor serviceDescriptor = fileDescriptor.findServiceByName(config.getService());
 			if (serviceDescriptor == null) {
@@ -262,6 +241,33 @@ private Descriptors.MethodDescriptor getMethodDescriptor(Config config, InputStr
 				.orElseThrow(() -> new NoSuchElementException("No Method found"));
 		}
 
+		private FileDescriptor[] dependencies(FileDescriptorSet input, ProtocolStringList list) {
+			FileDescriptor[] deps = new FileDescriptor[list.size()];
+			for (int i = 0; i < list.size(); i++) {
+				String name = list.get(i);
+				FileDescriptorProto file = findFileByName(input, name);
+				if (file == null) {
+					throw new IllegalStateException("Missing dependency: " + name);
+				}
+				try {
+					deps[i] = FileDescriptor.buildFrom(file, dependencies(input, file.getDependencyList()));
+				}
+				catch (DescriptorValidationException e) {
+					throw new IllegalStateException("Invalid descriptor: " + file.getName(), e);
+				}
+			}
+			return deps;
+		}
+
+		private FileDescriptorProto findFileByName(FileDescriptorSet input, String name) {
+			for (FileDescriptorProto file : input.getFileList()) {
+				if (file.getName().equals(name)) {
+					return file;
+				}
+			}
+			return null;
+		}
+
 		private ManagedChannel createChannel() {
 			URI requestURI = ((Route) exchange.getAttributes().get(ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR)).getUri();
 			return createChannelChannel(requestURI.getHost(), requestURI.getPort());
@@ -270,8 +276,9 @@ private ManagedChannel createChannel() {
 		private Function<JsonNode, DynamicMessage> callGRPCServer() {
 			return jsonRequest -> {
 				try {
-					byte[] request = objectWriter.writeValueAsBytes(jsonRequest);
-					return ClientCalls.blockingUnaryCall(clientCall, DynamicMessage.parseFrom(descriptor, request));
+					DynamicMessage.Builder builder = DynamicMessage.newBuilder(descriptor);
+					JsonFormat.parser().merge(jsonRequest.toString(), builder);
+					return ClientCalls.blockingUnaryCall(clientCall, builder.build());
 				}
 				catch (IOException e) {
 					throw new RuntimeException(e);
@@ -282,7 +289,8 @@ private Function<JsonNode, DynamicMessage> callGRPCServer() {
 		private Function<DynamicMessage, Object> serialiseGRPCResponse() {
 			return gRPCResponse -> {
 				try {
-					return objectReader.readValue(gRPCResponse.toByteArray());
+					return objectReader
+						.readValue(JsonFormat.printer().omittingInsignificantWhitespace().print(gRPCResponse));
 				}
 				catch (IOException e) {
 					throw new RuntimeException(e);

spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/route/builder/GatewayFilterSpec.java

@@ -284,16 +284,13 @@ public GatewayFilterSpec circuitBreaker(Consumer<SpringCloudCircuitBreakerFilter
 
 	/**
 	 * A filter that transforms a JSON request into a gRPC one.
-	 * @param protoDescriptor relative path to the proto descriptor file.
-	 * @param protoFile relative path to the proto definition file.
 	 * @param service fully qualified name of the service that will handle the request.
 	 * @param method method name in the service that will handle the request.
+	 * @param protoDescriptor relative path to the proto descriptor file.
 	 */
-	public GatewayFilterSpec jsonToGRPC(String protoDescriptor, String protoFile, String service, String method) {
-		return filter(getBean(JsonToGrpcGatewayFilterFactory.class).apply(c -> c.setMethod(method)
-			.setProtoDescriptor(protoDescriptor)
-			.setProtoFile(protoFile)
-			.setService(service)));
+	public GatewayFilterSpec jsonToGRPC(String service, String method, String protoDescriptor) {
+		return filter(getBean(JsonToGrpcGatewayFilterFactory.class)
+			.apply(c -> c.setMethod(method).setProtoDescriptor(protoDescriptor).setService(service)));
 	}
 
 	/**

spring-cloud-gateway-server/src/test/java/org/springframework/cloud/gateway/test/AdhocTestSuite.java

@@ -104,7 +104,6 @@
 		org.springframework.cloud.gateway.route.RouteTests.class,
 		org.springframework.cloud.gateway.route.CachingRouteLocatorTests.class,
 		org.springframework.cloud.gateway.route.RouteRefreshListenerTests.class,
-		org.springframework.cloud.gateway.route.builder.RouteDslTests.class,
 		org.springframework.cloud.gateway.route.builder.RouteBuilderTests.class,
 		org.springframework.cloud.gateway.route.builder.GatewayFilterSpecTests.class,
 		org.springframework.cloud.gateway.route.CachingRouteDefinitionLocatorTests.class,