Temporal 101 with Java trouble executing first practice assignment

Training
,
1

I get the following runtime warning and error executing the first practice assignment. I am trying to start the Worker
This is the command I execute.
mvn compile exec:java -D"exec.mainClass"=“helloworkflow.HelloWorkflowWorker”

What am I doing wrong?

thanks

[INFO]
[INFO] — exec-maven-plugin:3.3.0:java (default-cli) @ hello-workflow-practice —
[WARNING]
java.lang.NoClassDefFoundError: io/grpc/stub/ClientCalls$GrpcFuture
at io.grpc.stub.ClientCalls.futureUnaryCall (ClientCalls.java:226)
at io.grpc.stub.ClientCalls.blockingUnaryCall (ClientCalls.java:154)
at io.temporal.api.workflowservice.v1.WorkflowServiceGrpc$WorkflowServiceBlockingStub.getSystemInfo (WorkflowServiceGrpc.java:4141)
at io.temporal.serviceclient.SystemInfoInterceptor.getServerCapabilitiesOrThrow (SystemInfoInterceptor.java:95)
at io.temporal.serviceclient.ChannelManager.lambda$getServerCapabilities$3 (ChannelManager.java:330)
at io.temporal.internal.retryer.GrpcRetryer.retryWithResult (GrpcRetryer.java:60)
at io.temporal.serviceclient.ChannelManager.connect (ChannelManager.java:297)
at io.temporal.serviceclient.WorkflowServiceStubsImpl.connect (WorkflowServiceStubsImpl.java:161)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:77)
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke (Method.java:568)
at io.temporal.internal.WorkflowThreadMarker.lambda$protectFromWorkflowThread$1 (WorkflowThreadMarker.java:83)
at jdk.proxy3.$Proxy25.connect (Unknown Source)
at io.temporal.worker.WorkerFactory.start (WorkerFactory.java:213)
at helloworkflow.HelloWorkflowWorker.main (HelloWorkflowWorker.java:21)
at org.codehaus.mojo.exec.ExecJavaMojo.doMain (ExecJavaMojo.java:385)
at org.codehaus.mojo.exec.ExecJavaMojo.doExec (ExecJavaMojo.java:374)
at org.codehaus.mojo.exec.ExecJavaMojo.lambda$execute$0 (ExecJavaMojo.java:296)
at java.lang.Thread.run (Thread.java:842)
Caused by: java.lang.ClassNotFoundException: io.grpc.stub.ClientCalls$GrpcFuture
at org.codehaus.mojo.exec.URLClassLoaderBuilder$ExecJavaClassLoader.loadClass (URLClassLoaderBuilder.java:181)
at java.lang.ClassLoader.loadClass (ClassLoader.java:520)
at io.grpc.stub.ClientCalls.futureUnaryCall (ClientCalls.java:226)
at io.grpc.stub.ClientCalls.blockingUnaryCall (ClientCalls.java:154)
at io.temporal.api.workflowservice.v1.WorkflowServiceGrpc$WorkflowServiceBlockingStub.getSystemInfo (WorkflowServiceGrpc.java:4141)
at io.temporal.serviceclient.SystemInfoInterceptor.getServerCapabilitiesOrThrow (SystemInfoInterceptor.java:95)
at io.temporal.serviceclient.ChannelManager.lambda$getServerCapabilities$3 (ChannelManager.java:330)
at io.temporal.internal.retryer.GrpcRetryer.retryWithResult (GrpcRetryer.java:60)
at io.temporal.serviceclient.ChannelManager.connect (ChannelManager.java:297)
at io.temporal.serviceclient.WorkflowServiceStubsImpl.connect (WorkflowServiceStubsImpl.java:161)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:77)
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke (Method.java:568)
at io.temporal.internal.WorkflowThreadMarker.lambda$protectFromWorkflowThread$1 (WorkflowThreadMarker.java:83)
at jdk.proxy3.$Proxy25.connect (Unknown Source)
at io.temporal.worker.WorkerFactory.start (WorkerFactory.java:213)
at helloworkflow.HelloWorkflowWorker.main (HelloWorkflowWorker.java:21)
at org.codehaus.mojo.exec.ExecJavaMojo.doMain (ExecJavaMojo.java:385)
at org.codehaus.mojo.exec.ExecJavaMojo.doExec (ExecJavaMojo.java:374)
at org.codehaus.mojo.exec.ExecJavaMojo.lambda$execute$0 (ExecJavaMojo.java:296)
at java.lang.Thread.run (Thread.java:842)

And then

[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 20.629 s
[INFO] Finished at: 2024-06-16T17:57:47-04:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.codehaus.mojo:exec-maven-plugin:3.3.0:java (default-cli) on project hello-workflow-practice: An exception occurred while executing the Java class. io/grpc/stub/ClientCalls$GrpcFuture: io.grpc.stub.ClientCalls$GrpcFuture → [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:exec-maven-plugin:3.3.0:java (default-cli) on project hello-workflow-practice: An exception occurred while executing the Java class. io/grpc/stub/ClientCalls$GrpcFuture
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:215)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:148)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
at org.apache.maven.cli.MavenCli.execute (MavenCli.java:957)
at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:289)
at org.apache.maven.cli.MavenCli.main (MavenCli.java:193)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:77)
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke (Method.java:568)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406)
at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347)
Caused by: org.apache.maven.plugin.MojoExecutionException: An exception occurred while executing the Java class. io/grpc/stub/ClientCalls$GrpcFuture

2

It looks like the gRPC library version is not present or not compatible. Could you post your pom.xml file?

3

Here it is. It is from the HelloWorkflow practice exercise from temporal 101.
thanks

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>io.temporal.learn</groupId>
    <artifactId>hello-workflow-practice</artifactId>
    <version>1.0.0-SNAPSHOT</version>

    <name>hello-workflow (practice)</name>
    <url>https://learn.temporal.io/</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <dependencies>

        <dependency>
            <groupId>io.temporal</groupId>
            <artifactId>temporal-sdk</artifactId>
            <version>1.19.1</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-nop</artifactId>
            <version>2.0.6</version>
        </dependency>

        <dependency>
            <groupId>io.temporal</groupId>
            <artifactId>temporal-testing</artifactId>
            <version>1.19.1</version>
            <scope>test</scope>
        </dependency>  

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>
    
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>5.1.1</version>
            <scope>test</scope>
        </dependency>  
  
    </dependencies>

    <build>
        <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
            <plugins>
                <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
                <plugin>
                    <artifactId>maven-clean-plugin</artifactId>
                    <version>3.1.0</version>
                </plugin>
                <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
                <plugin>
                    <artifactId>maven-resources-plugin</artifactId>
                    <version>3.0.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.0</version>
                </plugin>
                <plugin>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <version>2.22.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-jar-plugin</artifactId>
                    <version>3.0.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-install-plugin</artifactId>
                    <version>2.5.2</version>
                </plugin>
                <plugin>
                    <artifactId>maven-deploy-plugin</artifactId>
                    <version>2.8.2</version>
                </plugin>
                <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
                <plugin>
                    <artifactId>maven-site-plugin</artifactId>
                    <version>3.7.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-project-info-reports-plugin</artifactId>
                    <version>3.0.0</version>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>
</project>
4

Can you post your version of Maven and Java? Trying to reproduce on our end. Also, are you performing this in the GitPod environment or on your own personal machine?

5

I am no longer sure this is an issue with the tutorial. I am going through our company mirror and it’s possible that our mirror doesn’t know how to get to this package.
But here are the details you asked for.

java -version
java version “17.0.9” 2023-10-17 LTS
Java™ SE Runtime Environment (build 17.0.9+11-LTS-201)
Java HotSpot™ 64-Bit Server VM (build 17.0.9+11-LTS-201, mixed mode, sharing)

Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)
Maven home: C:\Users\ss2187\Code\apache-maven-3.6.3-bin\apache-maven-3.6.3\bin..
Java version: 17.0.9, vendor: Oracle Corporation, runtime: C:\Program Files\Java\jdk-17
Default locale: en_US, platform encoding: Cp1252
OS name: “windows 11”, version: “10.0”, arch: “amd64”, family: “windows”

6

Ok. Thanks for the update. If you confirm the issue please let us know :slight_smile:

7

will do. Thanks for your help.

8

Hi Mason
Could you help me determine what package and version this failing on?
It’s a grpc library.

9

The GRPC library is brought in via the Temporal SDK. According to the gradle build sdk-java/build.gradle at master · temporalio/sdk-java · GitHub it’s this package io.grpc.protobuf.services.HealthStatusManager

10

Mason
thanks a lot.