Use GoogleDefaultChannelBuilder

build.gradle

@@ -26,7 +26,7 @@ apply plugin: 'io.codearte.nexus-staging'
 project.version = "1.35.2-SNAPSHOT" // {x-version-update:gax:current}
 
 ext {
-  grpcVersion = '1.16.1'
+  grpcVersion = '1.17.1'
   commonProtosVersion = '1.12.0'
   authVersion = '0.12.0'
   // Project names not used for release
@@ -116,6 +116,7 @@ subprojects {
         grpcAuth: "io.grpc:grpc-auth:${grpcVersion}",
         grpcProtobuf: "io.grpc:grpc-protobuf:${grpcVersion}",
         grpcNetty: "io.grpc:grpc-netty-shaded:${grpcVersion}",
+        grpcAlts: "io.grpc:grpc-alts:${grpcVersion}",
         gson: "com.google.code.gson:gson:2.7",
         guava: 'com.google.guava:guava:26.0-android',
         jsr305: 'com.google.code.findbugs:jsr305:3.0.2',

gax-grpc/build.gradle

@@ -15,7 +15,8 @@ dependencies {
     libraries.authCredentials,
     libraries.commonProtos,
     libraries.apiCommon,
-    libraries.grpcNetty
+    libraries.grpcNetty,
+    libraries.grpcAlts
 
   compileOnly libraries.autovalue
 

gax-grpc/src/main/java/com/google/api/gax/grpc/InstantiatingGrpcChannelProvider.java

@@ -41,8 +41,8 @@
 import com.google.common.collect.ImmutableList;
 import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
+import io.grpc.alts.GoogleDefaultChannelBuilder;
 import java.io.IOException;
-import java.lang.reflect.InvocationTargetException;
 import java.util.Map;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
@@ -184,49 +184,16 @@ private ManagedChannel createSingleChannel() throws IOException {
     int port = Integer.parseInt(endpoint.substring(colon + 1));
     String serviceAddress = endpoint.substring(0, colon);
 
-    // TODO(hzyi): Change to ManagedChannelBuilder directly when
-    // https://github.com/grpc/grpc-java/issues/4050 is resolved.
-    ManagedChannelBuilder builder;
+    ManagedChannelBuilder builder =
+        GoogleDefaultChannelBuilder.forAddress(serviceAddress, port)
+            .intercept(headerInterceptor)
+            .intercept(metadataHandlerInterceptor)
+            .userAgent(headerInterceptor.getUserAgentHeader())
+            .executor(executor);
+
     if (maxInboundMetadataSize != null) {
-      Class<?> nettyChannelBuilderClass;
-      try {
-        nettyChannelBuilderClass =
-            Class.forName("io.grpc.netty.shaded.io.grpc.netty.NettyChannelBuilder");
-      } catch (ClassNotFoundException e) {
-        try {
-          nettyChannelBuilderClass = Class.forName("io.grpc.netty.NettyChannelBuilder");
-        } catch (ClassNotFoundException ex) {
-          throw new RuntimeException(
-              "Unable to create the channel because neither"
-                  + " \"io.grpc.netty.NettyChannelBuilder\" nor"
-                  + " \"io.grpc.netty.shaded.io.grpc.netty.NettyChannelBuilder\" is found.");
-        }
-      }
-      try {
-        Object object =
-            nettyChannelBuilderClass
-                .getMethod("forAddress", String.class, int.class)
-                .invoke(null, serviceAddress, port);
-        object =
-            nettyChannelBuilderClass
-                .getMethod("maxHeaderListSize", int.class)
-                .invoke(object, maxInboundMetadataSize);
-        builder = (ManagedChannelBuilder) object;
-      } catch (NoSuchMethodException
-          | IllegalAccessException
-          | IllegalArgumentException
-          | InvocationTargetException e) {
-        throw new RuntimeException(
-            "Unable to set maxHeaderListSize due to exception: " + e.getMessage());
-      }
-    } else {
-      builder = ManagedChannelBuilder.forAddress(serviceAddress, port);
+      builder.maxInboundMetadataSize(maxInboundMetadataSize);
     }
-    builder
-        .intercept(headerInterceptor)
-        .intercept(metadataHandlerInterceptor)
-        .userAgent(headerInterceptor.getUserAgentHeader())
-        .executor(executor);
     if (maxInboundMessageSize != null) {
       builder.maxInboundMessageSize(maxInboundMessageSize);
     }