Why did lagom throw java.lang.ClassNotFoundException: com.lightbend.lagom.internal.javadsl.api.broker.TopicFactoryProvider?

Question

A previous attempt to run an initial lagom service failed after getting help on [getting a service listening][1].

So, on this attempt, a maven project (usvcs) has only two modules (actor-api and actor-impl) and a single service call 'echo'.

public interface MAIActorsService extends Service {
  ServiceCall<NotUsed, String> echo(String s);
  @Override
  default Descriptor descriptor() {
    // @formatter:off
    return named("cmai_actors").withCalls(
            restCall(Method.GET, "/echo/:s", this::echo)
      ).withAutoAcl(true);
    // @formatter:on
  }
}

and the implementation is a stub that doesn't have an entity reference.

@Override
public ServiceCall<NotUsed, String> echo(String s) {
    return request -> {
        CompletableFuture<String> alreadyCompleted = CompletableFuture.completedFuture(s);
        try {
            alreadyCompleted.get();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return alreadyCompleted;
      };
}

running 'mvn lagom:runAll' throws and exception stating an internal lagom dsl class is not found.

$ mvn lagom:runAll
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO]
[INFO] usvcs
[INFO] actor-api
[INFO] actor-impl
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building usvcs 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- lagom-maven-plugin:1.3.0-M1:runAll (default-cli) @ usvcs ---
[INFO] Starting Kafka
[INFO] Starting Cassandra
.[INFO] Did not find Netty's native epoll transport in the classpath, defaulting to NIO.
.........[INFO] Using data-center name 'datacenter1' for DCAwareRoundRobinPolicy (if this is incorrect, please provide the correct datacenter name with DCAwareRoundRobinPolicy constructor)
[INFO] New Cassandra host /127.0.0.1:4000 added
[INFO] Cassandra server running at 127.0.0.1:4000
[INFO] Service locator is running at http://localhost:8000
[INFO] Service gateway is running at http://localhost:9000
No play.logger.configurator found: logging must be configured entirely by the application.
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory C:\Users\lusp\maisvc\usvcs\actor-api\src\main\resources
[INFO] Nothing to compile - all classes are up to date
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Nothing to compile - all classes are up to date
java.lang.NoClassDefFoundError: com/lightbend/lagom/internal/javadsl/api/broker/TopicFactoryProvider
        at com.lightbend.lagom.internal.javadsl.registry.ServiceRegistryModule.configure(ServiceRegistryModule.scala:35)
        at com.google.inject.AbstractModule.configure(AbstractModule.java:62)
        at com.google.inject.spi.Elements$RecordingBinder.install(Elements.java:340)
        at com.google.inject.spi.Elements.getElements(Elements.java:110)
        at com.google.inject.util.Modules$OverrideModule.configure(Modules.java:177)
        at com.google.inject.AbstractModule.configure(AbstractModule.java:62)
        at com.google.inject.spi.Elements$RecordingBinder.install(Elements.java:340)
        at com.google.inject.spi.Elements.getElements(Elements.java:110)
        at com.google.inject.internal.InjectorShell$Builder.build(InjectorShell.java:138)
        at com.google.inject.internal.InternalInjectorCreator.build(InternalInjectorCreator.java:104)
        at com.google.inject.Guice.createInjector(Guice.java:96)
        at com.google.inject.Guice.createInjector(Guice.java:84)
        at play.api.inject.guice.GuiceBuilder.injector(GuiceInjectorBuilder.scala:181)
        at play.api.inject.guice.GuiceApplicationBuilder.build(GuiceApplicationBuilder.scala:123)
        at play.api.inject.guice.GuiceApplicationLoader.load(GuiceApplicationLoader.scala:21)
        at play.core.server.LagomReloadableDevServerStart$$anonfun$mainDev$1$$anon$2$$anonfun$get$1$$anonfun$apply$1$$anonfun$2$$anonfun$3.apply(LagomReloadableDevServerStart.scala:151)
        at play.core.server.LagomReloadableDevServerStart$$anonfun$mainDev$1$$anon$2$$anonfun$get$1$$anonfun$apply$1$$anonfun$2$$anonfun$3.apply(LagomReloadableDevServerStart.scala:148)
        at play.utils.Threads$.withContextClassLoader(Threads.scala:21)
        at play.core.server.LagomReloadableDevServerStart$$anonfun$mainDev$1$$anon$2$$anonfun$get$1$$anonfun$apply$1$$anonfun$2.apply(LagomReloadableDevServerStart.scala:148)
        at play.core.server.LagomReloadableDevServerStart$$anonfun$mainDev$1$$anon$2$$anonfun$get$1$$anonfun$apply$1$$anonfun$2.apply(LagomReloadableDevServerStart.scala:124)
        at scala.Option.map(Option.scala:146)
        at play.core.server.LagomReloadableDevServerStart$$anonfun$mainDev$1$$anon$2$$anonfun$get$1$$anonfun$apply$1.apply(LagomReloadableDevServerStart.scala:124)
        at play.core.server.LagomReloadableDevServerStart$$anonfun$mainDev$1$$anon$2$$anonfun$get$1$$anonfun$apply$1.apply(LagomReloadableDevServerStart.scala:122)
        at scala.util.Success.flatMap(Try.scala:231)
        at play.core.server.LagomReloadableDevServerStart$$anonfun$mainDev$1$$anon$2$$anonfun$get$1.apply(LagomReloadableDevServerStart.scala:122)
        at play.core.server.LagomReloadableDevServerStart$$anonfun$mainDev$1$$anon$2$$anonfun$get$1.apply(LagomReloadableDevServerStart.scala:114)
        at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
        at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
        at java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1402)
        at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
        at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
        at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
        at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Caused by: java.lang.ClassNotFoundException: com.lightbend.lagom.internal.javadsl.api.broker.TopicFactoryProvider
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        ... 33 more

Stacktrace caused by project target (filesystem path to project is C:\Users\lusp\maisvc\usvcs\actor-impl\target).

[INFO] Service actor-impl listening for HTTP on 0:0:0:0:0:0:0:0:62728
[INFO] (Service started, press enter to stop and go back to the console...)

The service doesn't work and the obvious question is whether or not stubbing the service call is not allowed???

UPDATE

Made some changes, still got the error, so I put the code up on github to document it more completely https://github.com/tevye/lagom-echo-project-from-scratch

Answer 1

Seems that You have maven dep problem. In parent pom.xml you have:

 <lagom.version>1.3.0-M1</lagom.version>

and this version is used by lagom maven plugin.

On the other hand all your lagom dependencies use version 1.2.1:

    <dependency>
        <groupId>com.lightbend.lagom</groupId>
        <artifactId>lagom-javadsl-persistence_2.11</artifactId>
        <version>1.2.1</version>
    </dependency>

try changing it to:

   <dependency>
        <groupId>com.lightbend.lagom</groupId>
        <artifactId>lagom-javadsl-persistence_2.11</artifactId>
        <version>${lagom.version}</version>
    </dependency>

Do it for all other lagom deps.

UPDATE

Your other problem seems to be 2 persistence providers

<dependency>
    <groupId>com.lightbend.lagom</groupId>
    <artifactId>lagom-javadsl-persistence-jdbc_2.11</artifactId>
</dependency>
<dependency>
    <groupId>com.lightbend.lagom</groupId>
    <artifactId>lagom-javadsl-persistence-cassandra_2.11</artifactId>
</dependency>

Remove dependency to: lagom-javadsl-persistence-jdbc_2.11 from pom(s).xml (especially actor-impl/pom.xml)

Also You do no need any of them in actor-api/pom.xml From com.lightbend.lagom leave there only lagom-javadsl-api_2.11