protobuf,examples: move json encoding to examples

4 files changed, 114 insertions, 5 deletions

diff --git a/examples/build.gradle b/examples/build.gradle
index c41857e86..f71a8d731 100644
--- a/examples/build.gradle
+++ b/examples/build.gradle
@@ -30,6 +30,8 @@ repositories {
 // updating the version in our release process.
 def grpcVersion = '1.13.0-SNAPSHOT' // CURRENT_GRPC_VERSION
 def nettyTcNativeVersion = '2.0.7.Final'
+def protobufVersion = '3.5.1'
+def protocVersion = '3.5.1-1'
 
 dependencies {
   compile "com.google.api.grpc:proto-google-common-protos:1.0.0"
@@ -42,6 +44,8 @@ dependencies {
   // Used for TLS in HelloWorldServerTls
   compile "io.netty:netty-tcnative-boringssl-static:${nettyTcNativeVersion}"
 
+  compile "com.google.protobuf:protobuf-java-util:${protobufVersion}"
+
   testCompile "io.grpc:grpc-testing:${grpcVersion}"
   testCompile "junit:junit:4.12"
   testCompile "org.mockito:mockito-core:1.9.5"
@@ -49,7 +53,7 @@ dependencies {
 
 protobuf {
   protoc {
-    artifact = 'com.google.protobuf:protoc:3.5.1-1'
+    artifact = "com.google.protobuf:protoc:${protocVersion}"
   }
   plugins {
     grpc {
diff --git a/examples/pom.xml b/examples/pom.xml
index c060f27ff..490685b36 100644
--- a/examples/pom.xml
+++ b/examples/pom.xml
@@ -12,6 +12,8 @@
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <grpc.version>1.13.0-SNAPSHOT</grpc.version><!-- CURRENT_GRPC_VERSION -->
+    <protobuf.version>3.5.1</protobuf.version>
+    <protoc.version>3.5.1-1</protoc.version>
     <netty.tcnative.version>2.0.7.Final</netty.tcnative.version>
   </properties>
   <dependencies>
@@ -52,6 +54,11 @@
       <version>1.0.0</version>
     </dependency>
     <dependency>
+      <groupId>com.google.protobuf</groupId>
+      <artifactId>protobuf-java-util</artifactId>
+      <version>${protobuf.version}</version>
+    </dependency>
+    <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
       <version>4.12</version>
@@ -78,7 +85,7 @@
         <artifactId>protobuf-maven-plugin</artifactId>
         <version>0.5.1</version>
         <configuration>
-          <protocArtifact>com.google.protobuf:protoc:3.5.1-1:exe:${os.detected.classifier}</protocArtifact>
+          <protocArtifact>com.google.protobuf:protoc:${protoc.version}:exe:${os.detected.classifier}</protocArtifact>
           <pluginId>grpc-java</pluginId>
           <pluginArtifact>io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}</pluginArtifact>
         </configuration>
diff --git a/examples/src/main/java/io/grpc/examples/advanced/HelloJsonClient.java b/examples/src/main/java/io/grpc/examples/advanced/HelloJsonClient.java
index 815734fb6..0e163168a 100644
--- a/examples/src/main/java/io/grpc/examples/advanced/HelloJsonClient.java
+++ b/examples/src/main/java/io/grpc/examples/advanced/HelloJsonClient.java
@@ -28,7 +28,6 @@ import io.grpc.examples.helloworld.GreeterGrpc;
 import io.grpc.examples.helloworld.HelloReply;
 import io.grpc.examples.helloworld.HelloRequest;
 import io.grpc.examples.helloworld.HelloWorldClient;
-import io.grpc.protobuf.ProtoUtils;
 import io.grpc.stub.AbstractStub;
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
@@ -98,8 +97,8 @@ public final class HelloJsonClient {
     static final MethodDescriptor<HelloRequest, HelloReply> METHOD_SAY_HELLO =
         GreeterGrpc.getSayHelloMethod()
             .toBuilder(
-                ProtoUtils.jsonMarshaller(HelloRequest.getDefaultInstance()),
-                ProtoUtils.jsonMarshaller(HelloReply.getDefaultInstance()))
+                JsonMarshaller.jsonMarshaller(HelloRequest.getDefaultInstance()),
+                JsonMarshaller.jsonMarshaller(HelloReply.getDefaultInstance()))
             .build();
 
     protected HelloJsonStub(Channel channel) {
diff --git a/examples/src/main/java/io/grpc/examples/advanced/JsonMarshaller.java b/examples/src/main/java/io/grpc/examples/advanced/JsonMarshaller.java
new file mode 100644
index 000000000..7b9aae94f
--- /dev/null
+++ b/examples/src/main/java/io/grpc/examples/advanced/JsonMarshaller.java
@@ -0,0 +1,99 @@
+/*
+ * Copyright 2018 The gRPC 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
+ *
+ *     http://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 io.grpc.examples.advanced;
+
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.google.protobuf.Message;
+import com.google.protobuf.Message.Builder;
+import com.google.protobuf.util.JsonFormat;
+import com.google.protobuf.util.JsonFormat.Parser;
+import com.google.protobuf.util.JsonFormat.Printer;
+import io.grpc.ExperimentalApi;
+import io.grpc.MethodDescriptor.Marshaller;
+import io.grpc.Status;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.nio.charset.Charset;
+
+/**
+ * A {@link Marshaller} for JSON.  This marshals in the Protobuf 3 format described here:
+ * https://developers.google.com/protocol-buffers/docs/proto3#json
+ */
+final class JsonMarshaller {
+
+  private JsonMarshaller() {}
+
+  /**
+   * Create a {@code Marshaller} for json protos of the same type as {@code defaultInstance}.
+   *
+   * <p>This is an unstable API and has not been optimized yet for performance.
+   */
+  public static <T extends Message> Marshaller<T> jsonMarshaller(final T defaultInstance) {
+    final Parser parser = JsonFormat.parser();
+    final Printer printer = JsonFormat.printer();
+    return jsonMarshaller(defaultInstance, parser, printer);
+  }
+
+  /**
+   * Create a {@code Marshaller} for json protos of the same type as {@code defaultInstance}.
+   *
+   * <p>This is an unstable API and has not been optimized yet for performance.
+   */
+  public static <T extends Message> Marshaller<T> jsonMarshaller(
+      final T defaultInstance, final Parser parser, final Printer printer) {
+
+    final Charset charset = Charset.forName("UTF-8");
+
+    return new Marshaller<T>() {
+      @Override
+      public InputStream stream(T value) {
+        try {
+          return new ByteArrayInputStream(printer.print(value).getBytes(charset));
+        } catch (InvalidProtocolBufferException e) {
+          throw Status.INTERNAL
+              .withCause(e)
+              .withDescription("Unable to print json proto")
+              .asRuntimeException();
+        }
+      }
+
+      @SuppressWarnings("unchecked")
+      @Override
+      public T parse(InputStream stream) {
+        Builder builder = defaultInstance.newBuilderForType();
+        Reader reader = new InputStreamReader(stream, charset);
+        T proto;
+        try {
+          parser.merge(reader, builder);
+          proto = (T) builder.build();
+          reader.close();
+        } catch (InvalidProtocolBufferException e) {
+          throw Status.INTERNAL.withDescription("Invalid protobuf byte sequence")
+              .withCause(e).asRuntimeException();
+        } catch (IOException e) {
+          // Same for now, might be unavailable
+          throw Status.INTERNAL.withDescription("Invalid protobuf byte sequence")
+              .withCause(e).asRuntimeException();
+        }
+        return proto;
+      }
+    };
+  }
+}