ClassNotFoundException when using quarkus:dev

Hello @quarkus Team 😃

I have a multimodule project with one of modules being an example subproject which exposes very simple REST API. Everything works fine when I start this example with a runner:

java -jar target/abberwoult-example-0.0.1-SNAPSHOT-runner.jar -cp target/lib/*

The resource is started and I can access REST API. This is ok but takes some time, so I wanted to use mvn quarkus:dev. I see that support for quarkus:dev in multimodule projects was introduced by https://github.com/quarkusio/quarkus/pull/1973 and thus should be working fine, But when I try to run my example with a dev mojo, that is:

$ cd abberwoult-example
$ mvn quarkus:dev

I’m getting the following error:

18:12:22,936 ERROR [io.qua.dev.DevModeMain] Failed to start quarkus: java.lang.ExceptionInInitializerError
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at java.lang.Class.newInstance(Class.java:442)
	at io.quarkus.runner.RuntimeRunner.run(RuntimeRunner.java:129)
	at io.quarkus.dev.DevModeMain.doStart(DevModeMain.java:173)
	at io.quarkus.dev.DevModeMain.main(DevModeMain.java:100)
Caused by: java.lang.RuntimeException: Failed to start quarkus
	at io.quarkus.runner.ApplicationImpl1.<clinit>(Unknown Source)
	... 8 more
Caused by: java.lang.IllegalStateException: Cannot load com.example.FruitRepositoryActor
	at com.github.sarxos.abberwoult.deployment.ActorInterceptorRegistryTemplate.register(ActorInterceptorRegistryTemplate.java:25)
	at io.quarkus.deployment.steps.AbberwoultProcessor$doRegisterActors9.deploy_0(Unknown Source)
	at io.quarkus.deployment.steps.AbberwoultProcessor$doRegisterActors9.deploy(Unknown Source)
	at io.quarkus.runner.ApplicationImpl1.<clinit>(Unknown Source)
	... 8 more
Caused by: java.lang.ClassNotFoundException: com.example.FruitRepositoryActor
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:264)
	at com.github.sarxos.abberwoult.deployment.ActorInterceptorRegistryTemplate.register(ActorInterceptorRegistryTemplate.java:23)
	... 11 more

This error comes from a @Template annotated class which is pretty simple:

@Template
public class ActorInterceptorRegistryTemplate {

	private static final Logger LOG = LoggerFactory.getLogger(ActorInterceptorRegistry.class);

	public void register(final String className) {

		final Class<?> clazz;
		try {
			clazz = Class.forName(className);
		} catch (ClassNotFoundException e) {
			throw new IllegalStateException("Cannot load " + className, e);
		}

		LOG.debug("Loaded {}", clazz);

		ActorInterceptorRegistry.registerReceiversFrom(clazz);
		ActorInterceptorRegistry.registerPreStartsFrom(clazz);
		ActorInterceptorRegistry.registerPostStopsFrom(clazz);
	}
}

I was able to w/a this by implementing custom class loader which loads classes directly from a known location, but some other issue (class not found exception, again) appeared which is probably linked to the same problem but is thrown from a synthetic beans so I gave up in digging more.

This is my custom class loader I implemented to (partially) workaround described problem:

public static class CustomClassLoader extends ClassLoader {

	@Override
	public Class<?> findClass(String name) throws ClassNotFoundException {
		final byte[] b = loadClassFromFile(name);
		return defineClass(name, b, 0, b.length);
	}

	private byte[] loadClassFromFile(final String className) throws ClassNotFoundException {

		LOG.debug("Loading class {}", className);

		final String resourcePath = className.replace('.', File.separatorChar) + ".class";

		int value = 0;

		try (
			final InputStream is = new FileInputStream(resourcePath);
			final ByteArrayOutputStream baos = new ByteArrayOutputStream()) {

			while ((value = is.read()) != -1) {
				baos.write(value);
			}

			return baos.toByteArray();

		} catch (FileNotFoundException e) {
			throw new ClassNotFoundException("Cannot find resource " + resourcePath, e);
		} catch (IOException e) {
			throw new IllegalStateException(e);
		}
	}
}

To reproduce:

$ git clone git@github.com:sarxos/abberwoult.git
$ cd abberwoult
$ mvn clean install -DskipTests
$ cd abberwoult-example
$ mvn quarkus:dev