java.lang.NoClassDefFoundError: org/jboss/resteasy/client/jaxrs/ResteasyClientBuilder

[ArtyomVancyan]

I have migrated our Keycloak version from 16.1.0 to 24.0.0, and all have been successful. It is run locally using the playground server and works as expected. Still, when I package the extensions and deploy them to the /opt/keycloak/providers directory of the Docker container, I get the following error (so the issue is caused only in Docker):

2024-04-25 10:15:16,205 ERROR [org.keycloak.services.error.KeycloakErrorHandler] (executor-thread-5) Uncaught server error: java.lang.NoClassDefFoundError: org/jboss/resteasy/client/jaxrs/ResteasyClientBuilder
	at com.sparsa.dix.idp.utils.AuthenticationServiceUtils.getAuthenticationServiceClient(AuthenticationServiceUtils.java:35)
	at com.sparsa.dix.idp.utils.AuthenticationServiceUtils.sendProofRequest(AuthenticationServiceUtils.java:49)
	at com.sparsa.dix.idp.rest.KeyCloakUserApiProvider.proofConnection(KeyCloakUserApiProvider.java:123)
	at com.sparsa.dix.idp.rest.KeyCloakUserApiProvider$quarkusrestinvoker$proofConnection_d9203c928a527328c0a13da0dbc659ec053e4b29.invoke(Unknown Source)
	at org.jboss.resteasy.reactive.server.handlers.InvocationHandler.handle(InvocationHandler.java:29)
	at io.quarkus.resteasy.reactive.server.runtime.QuarkusResteasyReactiveRequestContext.invokeHandler(QuarkusResteasyReactiveRequestContext.java:141)
	at org.jboss.resteasy.reactive.common.core.AbstractResteasyReactiveContext.run(AbstractResteasyReactiveContext.java:147)
	at io.quarkus.vertx.core.runtime.VertxCoreRecorder$14.runWith(VertxCoreRecorder.java:582)
	at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2513)
	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1538)
	at org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:29)
	at org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:29)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:840)
Caused by: java.lang.ClassNotFoundException: org.jboss.resteasy.client.jaxrs.ResteasyClientBuilder
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
	at io.quarkus.bootstrap.runner.RunnerClassLoader.loadClass(RunnerClassLoader.java:115)
	at io.quarkus.bootstrap.runner.RunnerClassLoader.loadClass(RunnerClassLoader.java:65)
	... 14 more

NOTE: No Maven dependencies have been changed during the migration process except adding jandex and replacing javax with jakarta.

What have we tried?

• We tried to shade packages using the maven-shade-plugin, but this didn't change the situation (the error was never changed).
• We ran mvn dependency:copy-dependencies and deployed the missing dependency JARs next to the providers, and this approach changed the error each time missing a new class from another dependency until we were facing version mismatches and overlaps.

The Question

Have anyone faced this kind of issue or have an idea how it can be fixed?

[shawkins]

Resteasy classic was mostly removed for the server in version 24. All that remained was resteasy-core-spi. Ideally you would switch your code to use resteasy reactive instead.

[ArtyomVancyan]

Currently, I use ResteasyClient in my custom authenticator. How should I change my code for initiating the new client? (Please provide the imports and the equivalent for the ResteasyClientBuilder.newClient() part)

import org.jboss.resteasy.client.jaxrs.ResteasyClient;
import org.jboss.resteasy.client.jaxrs.ResteasyClientBuilder;

public abstract class AuthenticatorBase extends UsernamePasswordForm {
    protected ResteasyClient getAuthenticationServiceClient() {
        return (ResteasyClient) ResteasyClientBuilder.newClient();  // source of the error
    }
}

[shawkins]

Sorry, I was pointing out the server dependency. The client dependency is resteasy-reactive-client - however that is not included in the server, so you would need to install it in the server as well.

Thinking about it more I think it should still be possible to use the resteasy client classic (it's problematic to continue to use the classic server dependency), but you'll need to install that dependency, and any missing transitive dependencies - either directly in the providers directory or packaged into your jar.

[ArtyomVancyan]

Resteasy classic was mostly removed for the server in version 24.

Well, based on your main answer, I got rid of all Resteasy dependencies already and changed my code as follows but the issue of not finding dependencies still remains.

import jakarta.ws.rs.client.Client;
import jakarta.ws.rs.client.ClientBuilder;

public abstract class AuthenticatorBase extends UsernamePasswordForm {
    protected Client getAuthenticationServiceClient() {
        return ClientBuilder.newClient();  // source of the error
    }
}

The new error just looks identical, so it's less likely a Resteasy issue:

2024-04-25 11:54:00,826 ERROR [org.keycloak.services.error.KeycloakErrorHandler] (executor-thread-5) Uncaught server error: java.lang.RuntimeException: java.lang.ClassNotFoundException: Provider for jakarta.ws.rs.client.ClientBuilder cannot be found
	at jakarta.ws.rs.client.ClientBuilder.newBuilder(ClientBuilder.java:75)
	at jakarta.ws.rs.client.ClientBuilder.newClient(ClientBuilder.java:86)
	at com.sparsa.dix.idp.utils.AuthenticationServiceUtils.getAuthenticationServiceClient(AuthenticationServiceUtils.java:31)
	at com.sparsa.dix.idp.utils.AuthenticationServiceUtils.sendProofRequest(AuthenticationServiceUtils.java:45)
	at com.sparsa.dix.idp.rest.KeyCloakUserApiProvider.proofConnection(KeyCloakUserApiProvider.java:121)
	at com.sparsa.dix.idp.rest.KeyCloakUserApiProvider$quarkusrestinvoker$proofConnection_d9203c928a527328c0a13da0dbc659ec053e4b29.invoke(Unknown Source)
	at org.jboss.resteasy.reactive.server.handlers.InvocationHandler.handle(InvocationHandler.java:29)
	at io.quarkus.resteasy.reactive.server.runtime.QuarkusResteasyReactiveRequestContext.invokeHandler(QuarkusResteasyReactiveRequestContext.java:141)
	at org.jboss.resteasy.reactive.common.core.AbstractResteasyReactiveContext.run(AbstractResteasyReactiveContext.java:147)
	at io.quarkus.vertx.core.runtime.VertxCoreRecorder$14.runWith(VertxCoreRecorder.java:582)
	at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2513)
	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1538)
	at org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:29)
	at org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:29)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:840)
Caused by: java.lang.ClassNotFoundException: Provider for jakarta.ws.rs.client.ClientBuilder cannot be found
	at jakarta.ws.rs.client.FactoryFinder.find(FactoryFinder.java:163)
	at jakarta.ws.rs.client.ClientBuilder.newBuilder(ClientBuilder.java:62)
	... 15 more

[shawkins]

You can check the lib/lib directory for everything that's known to keycloak at runtime. This message is saying that no provider is installed - which is correct. Keycloak does not have a client implementation in the runtime by default. You would still have to install the resteasy classic client (or another provider), and all needed transitive dependencies to make that work.

[ArtyomVancyan]

@shawkins, your answer didn't exactly solve my problem but you gave me an idea for solving it. Thank you!