About Akka gRPC

Akka Akka gRPC
1

Hi~
I’m trying to use Akka-gRPC .First , I flow the guide Server .
My development environment:

JDK 11.0.16

Maven configuration:
<properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <akka.grpc.version>2.3.0</akka.grpc.version>
        <grpc.version>1.48.1</grpc.version>
        <project.encoding>UTF-8</project.encoding>
    </properties>
    <dependencies>
        <dependency>
            <groupId>com.lightbend.akka.grpc</groupId>
            <artifactId>akka-grpc-runtime_2.12</artifactId>
            <version>${akka.grpc.version}</version>
        </dependency>

        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java</artifactId>
            <version>3.21.9</version>
        </dependency>
        <dependency>
            <groupId>com.thesamet.scalapb</groupId>
            <artifactId>scalapb-runtime_2.12</artifactId>
            <version>0.11.11</version>
        </dependency>
        <dependency>
            <groupId>com.typesafe.akka</groupId>
            <artifactId>akka-discovery_2.12</artifactId>
            <version>2.7.0</version>
        </dependency>
        <dependency>
            <groupId>com.typesafe.akka</groupId>
            <artifactId>akka-http-core_2.12</artifactId>
            <version>10.5.0-M1</version>
        </dependency>
        <dependency>
            <groupId>com.typesafe.akka</groupId>
            <artifactId>akka-http_2.12</artifactId>
            <version>10.5.0-M1</version>
        </dependency>
        <dependency>
            <groupId>com.typesafe.akka</groupId>
            <artifactId>akka-stream_2.12</artifactId>
            <version>2.7.0</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-core</artifactId>
            <version>1.48.1</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-netty-shaded</artifactId>
            <version>1.48.1</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-protobuf</artifactId>
            <version>1.48.1</version>
        </dependency>
        <dependency>
            <groupId>org.scala-lang</groupId>
            <artifactId>scala-library</artifactId>
            <version>2.12.17</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>com.lightbend.akka.grpc</groupId>
                <artifactId>akka-grpc-maven-plugin</artifactId>
                <version>${akka.grpc.version}</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>generate</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

proto file : src/main/java/proto/helloworld.proto

When I use “mvn akka-grpc:generate” command , the problem is

[WARNING] Error injecting: akka.grpc.maven.GenerateMojo
java.lang.NoClassDefFoundError: scala/math/Ordering
    at java.lang.Class.getDeclaredConstructors0 (Native Method)
    at java.lang.Class.privateGetDeclaredConstructors (Class.java:3137)
    at java.lang.Class.getDeclaredConstructors (Class.java:2357)
    at com.google.inject.spi.InjectionPoint.forConstructorOf (InjectionPoint.java:245)
    at com.google.inject.internal.ConstructorBindingImpl.create (ConstructorBindingImpl.java:115)
    at com.google.inject.internal.InjectorImpl.createUninitializedBinding (InjectorImpl.java:706)
    at com.google.inject.internal.InjectorImpl.createJustInTimeBinding (InjectorImpl.java:930)
    at com.google.inject.internal.InjectorImpl.createJustInTimeBindingRecursive (InjectorImpl.java:852)
    at com.google.inject.internal.InjectorImpl.getJustInTimeBinding (InjectorImpl.java:291)
    at com.google.inject.internal.InjectorImpl.getBindingOrThrow (InjectorImpl.java:222)
    at com.google.inject.internal.InjectorImpl.getProviderOrThrow (InjectorImpl.java:1040)
    at com.google.inject.internal.InjectorImpl.getProvider (InjectorImpl.java:1071)
    at com.google.inject.internal.InjectorImpl.getProvider (InjectorImpl.java:1034)
    at com.google.inject.internal.InjectorImpl.getInstance (InjectorImpl.java:1086)
    at org.eclipse.sisu.space.AbstractDeferredClass.get (AbstractDeferredClass.java:48)
    at com.google.inject.internal.ProviderInternalFactory.provision (ProviderInternalFactory.java:85)
    at com.google.inject.internal.InternalFactoryToInitializableAdapter.provision (InternalFactoryToInitializableAdapter.java:57)
    at com.google.inject.internal.ProviderInternalFactory$1.call (ProviderInternalFactory.java:66)
    at com.google.inject.internal.ProvisionListenerStackCallback$Provision.provision (ProvisionListenerStackCallback.java:112)
    at org.eclipse.sisu.bean.BeanScheduler$CycleActivator.onProvision (BeanScheduler.java:230)
    at com.google.inject.internal.ProvisionListenerStackCallback$Provision.provision (ProvisionListenerStackCallback.java:120)
    at com.google.inject.internal.ProvisionListenerStackCallback.provision (ProvisionListenerStackCallback.java:66)
    at com.google.inject.internal.ProviderInternalFactory.circularGet (ProviderInternalFactory.java:61)
    at com.google.inject.internal.InternalFactoryToInitializableAdapter.get (InternalFactoryToInitializableAdapter.java:47)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter.get (ProviderToInternalFactoryAdapter.java:40)
    at com.google.inject.internal.SingletonScope$1.get (SingletonScope.java:168)
    at com.google.inject.internal.InternalFactoryToProviderAdapter.get (InternalFactoryToProviderAdapter.java:39)
    at com.google.inject.internal.InjectorImpl$1.get (InjectorImpl.java:1050)
    at org.eclipse.sisu.inject.LazyBeanEntry.getValue (LazyBeanEntry.java:81)
    at org.eclipse.sisu.plexus.LazyPlexusBean.getValue (LazyPlexusBean.java:51)
    at org.codehaus.plexus.DefaultPlexusContainer.lookup (DefaultPlexusContainer.java:263)
    at org.codehaus.plexus.DefaultPlexusContainer.lookup (DefaultPlexusContainer.java:255)
    at org.apache.maven.plugin.internal.DefaultMavenPluginManager.getConfiguredMojo (DefaultMavenPluginManager.java:520)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:124)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:210)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:148)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:957)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:289)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:193)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:566)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347)
    at org.codehaus.classworlds.Launcher.main (Launcher.java:47)

Please,how to solve it . Wait your reply :smile:

1 Like
2

Can you try and see if the quickstart maven project compiles as expected? Akka gRPC Quickstart with Java · Lightbend Tech Hub

3

Because the sample project failed to compile ,so I want to follow the document once

4

So the quickstart fails as well? I wonder because if the quickstart maven project works fine we could compare the pom.xml here to yours and perhaps see how they differ.

5

en…I’m start from quickstart , when I execute akka-grpc:generate it prompt the same error message .
Then, I installed protoc of version libprotoc 3.21.9 ,and use command “protoc --java_out . helloworld.proto” ,but some class not found : GreeterServiceClient ,GreeterServiceHandlerFactory,GreeterService .

6

That’s unfortunate.

Akka gRPC does not rely on a local installation of protobuf but pulls it in via a maven dependency so that local libprotoc version is not needed and should not matter.

Just to doublecheck there was no regression I pulled the quickstart and built it, without problems, so not sure what is the cause of the problems you are having.

What OS and Java version are you using? I see lines for eclipse in your original stacktrace, are you triggering maven through Eclipse, and if so, could you try the same via the command line and see if it works there?

7

OS:Windows 10 21H2
jdk:JDK 11.0.16

I’ll try to deal with this problem again.