[Bug]: Regression - Build-time injection fails without AgentExecutor in Quarkus (after fix #215)

[hakdogan]

What happened?

Description

I reported an issue about build-time injection failure for unused beans from the a2a-java-reference-server dependency.

This was supposed to be fixed by PR #215 related to issue #213.

After the new version of the A2A Java SDK was released, I verified whether the issue still occurred.
At compile time, I still got an UnsatisfiedResolutionException.

Steps to Reproduce

1. Add dependency a2a-java-sdk-reference-jsonrpc
2. Do not provide AgentCard and AgentExecutor
3. Build the project

Result: UnsatisfiedResolutionException occurs at build time.

Expected Behavior

Build should succeed without requiring AgentExecutor (as the previous fix intended).

Notes

• If AgentExecutor is provided, the mentioned build-time error does not occur, even if AgentCard is not provided.
• This behavior seems different from the previous case and may indicate the fix was only partial.

Relevant log output

[ERROR] Failed to execute goal io.quarkus.platform:quarkus-maven-plugin:3.24.3:build (default) on project financial-agent: Failed to build quarkus application: io.quarkus.builder.BuildException: Build failure: Build failed due to errors
[ERROR]         [error]: Build step io.quarkus.arc.deployment.ArcProcessor#validate threw an exception: jakarta.enterprise.inject.spi.DeploymentException: jakarta.enterprise.inject.UnsatisfiedResolutionException: Unsatisfied dependency for type io.a2a.server.agentexecution.AgentExecutor and qualifiers [@Default]
[ERROR]         - injection target: parameter 'agentExecutor' of io.a2a.server.requesthandlers.DefaultRequestHandler constructor
[ERROR]         - declared on CLASS bean [types=[io.a2a.server.requesthandlers.DefaultRequestHandler, java.lang.Object, io.a2a.server.requesthandlers.RequestHandler], qualifiers=[@Default, @Any], target=io.a2a.server.requesthandlers.DefaultRequestHandler]
[ERROR]         at io.quarkus.arc.processor.BeanDeployment.processErrors(BeanDeployment.java:1594)
[ERROR]         at io.quarkus.arc.processor.BeanDeployment.init(BeanDeployment.java:341)
[ERROR]         at io.quarkus.arc.processor.BeanProcessor.initialize(BeanProcessor.java:178)
[ERROR]         at io.quarkus.arc.deployment.ArcProcessor.validate(ArcProcessor.java:488)
[ERROR]         at java.base/java.lang.invoke.MethodHandle.invokeWithArguments(MethodHandle.java:733)
[ERROR]         at io.quarkus.deployment.ExtensionLoader$3.execute(ExtensionLoader.java:856)
[ERROR]         at io.quarkus.builder.BuildContext.run(BuildContext.java:255)
[ERROR]         at org.jboss.threads.ContextHandler$1.runWith(ContextHandler.java:18)
[ERROR]         at org.jboss.threads.EnhancedQueueExecutor$Task.doRunWith(EnhancedQueueExecutor.java:2651)
[ERROR]         at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2630)
[ERROR]         at org.jboss.threads.EnhancedQueueExecutor.runThreadBody(EnhancedQueueExecutor.java:1622)
[ERROR]         at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1589)
[ERROR]         at java.base/java.lang.Thread.run(Thread.java:1570)
[ERROR]         at org.jboss.threads.JBossThread.run(JBossThread.java:501)
[ERROR] Caused by: jakarta.enterprise.inject.UnsatisfiedResolutionException: Unsatisfied dependency for type io.a2a.server.agentexecution.AgentExecutor and qualifiers [@Default]
[ERROR]         - injection target: parameter 'agentExecutor' of io.a2a.server.requesthandlers.DefaultRequestHandler constructor
[ERROR]         - declared on CLASS bean [types=[io.a2a.server.requesthandlers.DefaultRequestHandler, java.lang.Object, io.a2a.server.requesthandlers.RequestHandler], qualifiers=[@Default, @Any], target=io.a2a.server.requesthandlers.DefaultRequestHandler]
[ERROR]         at io.quarkus.arc.processor.Beans.resolveInjectionPoint(Beans.java:547)
[ERROR]         at io.quarkus.arc.processor.BeanInfo.init(BeanInfo.java:689)
[ERROR]         at io.quarkus.arc.processor.BeanDeployment.init(BeanDeployment.java:326)
[ERROR]         ... 12 more

Code of Conduct

• I agree to follow this project's Code of Conduct

[kabir]

Strange, I can see the DefaultProducers class in the a2a-java-sdk-reference-common module.

In the tck/ module I have commented out the @Produces annotations in the AgentCardProducer and AgentCardExecutor and see the same issue as you.

However, the dependency is there:

[~/sourcecontrol/AI/a2aproject/a2a-java] 
% mvn dependency:tree -pl tck 
[INFO] Scanning for projects...
[INFO] Inspecting build with total of 1 modules
[INFO] Installing Central Publishing features
[INFO] 
[INFO] ------------------< io.github.a2asdk:a2a-tck-server >-------------------
[INFO] Building Java SDK A2A TCK Server 0.3.0.Beta1-SNAPSHOT
[INFO]   from pom.xml
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- dependency:3.7.0:tree (default-cli) @ a2a-tck-server ---
[INFO] io.github.a2asdk:a2a-tck-server:jar:0.3.0.Beta1-SNAPSHOT
[INFO] +- io.github.a2asdk:a2a-java-sdk-reference-jsonrpc:jar:0.3.0.Beta1-SNAPSHOT:compile
[INFO] |  +- io.github.a2asdk:a2a-java-sdk-reference-common:jar:0.3.0.Beta1-SNAPSHOT:compile
...

[kabir]

Ah it was using jakarta.ws.rs.Produces rather than the CDI annotation. I've been doing that a lot recently!

#271 should fix it

[hakdogan]

@kabir I had reviewed the DefaultProducer, but I think I missed this detail due to code folding. Honestly, it never occurred to me that the issue could be caused by such a mix-up.

I'm glad the problem is now clear 👍