Background Context

Hi everyone

I am implementing an Executor in a Spring Boot REST web app to execute all @Async methods.

I am implementing a custom ThreadFactory because of this HazelcastException being thrown:

com.hazelcast.nio.serialization.HazelcastSerializationException: java.lang.ClassNotFoundException: com.company.group.common.model.APIResult Error happens during Process ABC: java.lang.ClassNotFoundException: com.company.group.common.model.APIResult

We encountered this same Hazelcast exception before with services that use ForkJoinPool & implemented the following:

CustomForkJoinWorkerThreadFactory.java

import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ForkJoinWorkerThread;

public class CustomForkJoinWorkerThreadFactory implements ForkJoinPool.ForkJoinWorkerThreadFactory {

    @Override
    public final ForkJoinWorkerThread newThread(ForkJoinPool pool) {
        return new CustomForkJoinWorkerThread(pool);
    }

    private static class CustomForkJoinWorkerThread extends ForkJoinWorkerThread {
        private CustomForkJoinWorkerThread(final ForkJoinPool pool) {
            super(pool);
            // set the correct classloader here
            setContextClassLoader(Thread.currentThread().getContextClassLoader());
        }
    }
}

Service.java in the service using ForkJoinPool

ForkJoinPool fjp = new ForkJoinPool(90, new CustomForkJoinWorkerThreadFactory(), null, false);

My Implementation using ThreadPoolExecutor

Now I want to use a ThreadPoolExecutor & implemented the following:

MyApp.java

...
  @Override
  public Executor getAsyncExecutor() {
    return new ThreadPoolExecutor(10, 50, 30, TimeUnit.SECONDS, new SynchronousQueue<>(),
            new CustomThreadFactory());
  }
...

MyService.java

public void executeProcessA() {
  ...
  executeProcessB();
  // just after calling process B, the Hazelcast exception is thrown
  ...
}

@Async
public void executeProcessB() {
  ...
}

CustomThreadFactory.java

import java.util.concurrent.ThreadFactory;

public class CustomThreadFactory implements ThreadFactory {
    @Override
    public Thread newThread(Runnable r) {
        return new CustomThread(r);
    }

    private static class CustomThread extends Thread {
        private CustomThread(final Runnable r) {
            super(r);
            setContextClassLoader(Thread.currentThread().getContextClassLoader());
        }
    }
}

Current Situation

In executeProcessA() of MyService.java, just after executeProcessB() is called, the following Hazelcast exception is thrown.

com.hazelcast.nio.serialization.HazelcastSerializationException: java.lang.ClassNotFoundException: com.company.group.common.model.APIResult Error happens during Process ABC: java.lang.ClassNotFoundException: com.company.group.common.model.APIResult

Is there anything fundamentally different between a ForkJoinPool & ThreadPoolExecutor that I’m missing in my implementation?