grpc protobuf java中的NoSuchMethodException和NoClassDefFoundError

Question

我启动了一个 gRPC 服务，一切都很好，没有错误。但是，当我尝试使用grpcui (./grpcui -plaintext localhost:9900) 来读取服务时，我得到以下信息：

Exception in thread "grpc-default-executor-0" java.lang.NoSuchMethodError: com.google.protobuf.Descriptors$FileDescriptor.internalBuildGeneratedFileFrom([Ljava/lang/String;[Lcom/google/protobuf/Descriptors$FileDescriptor;)Lcom/google/protobuf/Descriptors$FileDescriptor;
    at io.grpc.reflection.v1alpha.ServerReflectionProto.<clinit>(ServerReflectionProto.java:103)
    at io.grpc.reflection.v1alpha.ServerReflectionGrpc$ServerReflectionBaseDescriptorSupplier.getFileDescriptor(ServerReflectionGrpc.java:234)
    at io.grpc.protobuf.services.ProtoReflectionService$FileDescriptorIndex.<init>(ProtoReflectionService.java:418)
    at io.grpc.protobuf.services.ProtoReflectionService$ServerReflectionIndex.<init>(ProtoReflectionService.java:339)
    at io.grpc.protobuf.services.ProtoReflectionService.updateIndexIfNecessary(ProtoReflectionService.java:97)
    at io.grpc.protobuf.services.ProtoReflectionService.serverReflectionInfo(ProtoReflectionService.java:136)
    at io.grpc.reflection.v1alpha.ServerReflectionGrpc$MethodHandlers.invoke(ServerReflectionGrpc.java:220)
    at io.grpc.stub.ServerCalls$StreamingServerCallHandler.startCall(ServerCalls.java:224)
    at io.grpc.internal.ServerImpl$ServerTransportListenerImpl.startWrappedCall(ServerImpl.java:648)
    at io.grpc.internal.ServerImpl$ServerTransportListenerImpl.startCall(ServerImpl.java:626)
    at io.grpc.internal.ServerImpl$ServerTransportListenerImpl.access$1900(ServerImpl.java:417)
    at io.grpc.internal.ServerImpl$ServerTransportListenerImpl$1StreamCreated.runInternal(ServerImpl.java:556)
    at io.grpc.internal.ServerImpl$ServerTransportListenerImpl$1StreamCreated.runInContext(ServerImpl.java:531)
    at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
    at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

和

Exception in thread "grpc-default-executor-1" java.lang.NoClassDefFoundError: Could not initialize class io.grpc.reflection.v1alpha.ServerReflectionProto
    at io.grpc.reflection.v1alpha.ServerReflectionGrpc$ServerReflectionBaseDescriptorSupplier.getFileDescriptor(ServerReflectionGrpc.java:234)
    at io.grpc.protobuf.services.ProtoReflectionService$FileDescriptorIndex.<init>(ProtoReflectionService.java:418)
    at io.grpc.protobuf.services.ProtoReflectionService$ServerReflectionIndex.<init>(ProtoReflectionService.java:339)
    at io.grpc.protobuf.services.ProtoReflectionService.updateIndexIfNecessary(ProtoReflectionService.java:97)
    at io.grpc.protobuf.services.ProtoReflectionService.serverReflectionInfo(ProtoReflectionService.java:136)
    at io.grpc.reflection.v1alpha.ServerReflectionGrpc$MethodHandlers.invoke(ServerReflectionGrpc.java:220)
    at io.grpc.stub.ServerCalls$StreamingServerCallHandler.startCall(ServerCalls.java:224)
    at io.grpc.internal.ServerImpl$ServerTransportListenerImpl.startWrappedCall(ServerImpl.java:648)
    at io.grpc.internal.ServerImpl$ServerTransportListenerImpl.startCall(ServerImpl.java:626)
    at io.grpc.internal.ServerImpl$ServerTransportListenerImpl.access$1900(ServerImpl.java:417)
    at io.grpc.internal.ServerImpl$ServerTransportListenerImpl$1StreamCreated.runInternal(ServerImpl.java:556)
    at io.grpc.internal.ServerImpl$ServerTransportListenerImpl$1StreamCreated.runInContext(ServerImpl.java:531)
    at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
    at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

我的服务：

public class OneSideInitiated extends SideGrpc.SideImplBase {

    @Override
    public void requestStart(RemoteStartRequest request,
                                        StreamObserver<RemoteStartResponse> responseObserver) {

        RemoteStartResponse response = RemoteStartResponse.newBuilder().build();

        responseObserver.onNext(response);
        responseObserver.onCompleted();
    }
}

启动服务的类：

import io.grpc.Server;
import io.grpc.ServerBuilder;
import io.grpc.protobuf.services.ProtoReflectionService;

public class StuffServer {

    private Server server;

    public StuffServer(int port) {

        this.server = ServerBuilder.forPort(port)
                .addService(ProtoReflectionService.newInstance())
                .addService(new OneSideInitiated())
                .build();
    }

    public void start() throws IOException {
        server.start();
    }

    public void stop() throws InterruptedException {...}

    public static void main(String[] args) throws Exception {
        CccpServer cccpServer = new StuffServer(9900);
        cccpServer.start();
        cccpServer.blockUntilShutdown();
    }

    private void blockUntilShutdown() throws InterruptedException {...}
}

我的 Maven 依赖项是：

        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-stub</artifactId>
            <version>1.26.0</version>
        </dependency>

        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-core</artifactId>
            <version>1.26.0</version>
        </dependency>

        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-netty</artifactId>
            <version>1.26.0</version>
        </dependency>

        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-services</artifactId>
            <version>1.26.0</version>
        </dependency>

        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>23.6.1-jre</version>
        </dependency>

        <dependency>
            <groupId>com.google.api.grpc</groupId>
            <artifactId>proto-google-common-protos</artifactId>
            <version>0.1.9</version>
        </dependency>

        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-testing</artifactId>
            <version>1.26.0</version>
            <scope>testing</scope>
        </dependency>

尝试了guava 和io.grpc 版本的不同组合，没有任何区别。 有人对此有任何想法吗？

Answer 1

这个特定的 FileDescriptor.internalBuildGeneratedFileFrom() 方法在 v3.8 中被添加到 Protobuf。一般NoSuchMethodError 错误是由于依赖被降级导致的，通常是由 Maven 造成的。

您可以运行mvn dependency:tree 来检查正在使用哪些版本的依赖项。在这种情况下，您会发现com.google.api.grpc:proto-google-common-protos:0.1.9 依赖于com.google.protobuf:protobuf-java:3.2.0，这是 Maven 使用的版本。

gRPC 团队建议始终使用 Maven Enforcer 的requireUpperBoundDeps 来检测 Maven 何时错误地选择版本。您可以添加到您的 pom.xml：

    <plugins>
      ...
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-enforcer-plugin</artifactId>
        <version>1.4.1</version>
        <executions>
          <execution>
            <id>enforce</id>
            <goals>
              <goal>enforce</goal>
            </goals>
            <configuration>
              <rules>
                <requireUpperBoundDeps/>
              </rules>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>

当它在构建过程中检测到故障时，它会提供其他地方依赖的版本。选择最大的版本并将其作为显式依赖项添加到您的项目中：

    <dependency>
      <groupId>com.google.protobuf</groupId>
      <artifactId>protobuf-java</artifactId>
      <version>3.11.0</version>
    </dependency>

我还会注意到 proto-google-common-protos:0.1.9 已经很老了。我建议更新到更新的版本，例如 1.17.0。尽管您在 1.17.0 中仍然会遇到此问题。