Scheduler - use an application class predicate when generating invokers

- until now all invokers were considered application classes, i.e. they
were always loaded by the Runtime Class Loader in the dev mode and so a
package-private scheduled method defined in a dependency resulted in an
IllegalAccessError
- resolves #17492

(cherry picked from commit a5acdc9)

extensions/scheduler/deployment/src/main/java/io/quarkus/scheduler/deployment/SchedulerProcessor.java

@@ -3,13 +3,15 @@
 import static io.quarkus.deployment.annotations.ExecutionTime.RUNTIME_INIT;
 import static io.quarkus.deployment.annotations.ExecutionTime.STATIC_INIT;
 
+import java.lang.reflect.Modifier;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 
 import org.jboss.jandex.AnnotationInstance;
 import org.jboss.jandex.AnnotationValue;
@@ -88,6 +90,7 @@ public class SchedulerProcessor {
             Kind.CLASS);
 
     static final String INVOKER_SUFFIX = "_ScheduledInvoker";
+    static final String NESTED_SEPARATOR = "$_";
 
     @BuildStep
     void beans(Capabilities capabilities, BuildProducer<AdditionalBeanBuildItem> additionalBeans) {
@@ -159,6 +162,12 @@ void validateScheduledBusinessMethods(SchedulerConfig config, List<ScheduledBusi
         for (ScheduledBusinessMethodItem scheduledMethod : scheduledMethods) {
             MethodInfo method = scheduledMethod.getMethod();
 
+            if (Modifier.isPrivate(method.flags()) || Modifier.isStatic(method.flags())) {
+                errors.add(new IllegalStateException("@Scheduled method must be non-private and non-static: "
+                        + method.declaringClass().name() + "#" + method.name() + "()"));
+                continue;
+            }
+
             // Validate method params and return type
             List<Type> params = method.parameters();
             if (params.size() > 1
@@ -198,11 +207,24 @@ public List<UnremovableBeanBuildItem> unremovableBeans() {
     @Record(RUNTIME_INIT)
     public FeatureBuildItem build(SchedulerConfig config, BuildProducer<SyntheticBeanBuildItem> syntheticBeans,
             SchedulerRecorder recorder, List<ScheduledBusinessMethodItem> scheduledMethods,
-            BuildProducer<GeneratedClassBuildItem> generatedClass, BuildProducer<ReflectiveClassBuildItem> reflectiveClass,
+            BuildProducer<GeneratedClassBuildItem> generatedClasses, BuildProducer<ReflectiveClassBuildItem> reflectiveClass,
             AnnotationProxyBuildItem annotationProxy, ExecutorBuildItem executor) {
 
         List<ScheduledMethodMetadata> scheduledMetadata = new ArrayList<>();
-        ClassOutput classOutput = new GeneratedClassGizmoAdaptor(generatedClass, true);
+        ClassOutput classOutput = new GeneratedClassGizmoAdaptor(generatedClasses, new Function<String, String>() {
+            @Override
+            public String apply(String name) {
+                // org/acme/Foo_ScheduledInvoker_run_0000 -> org.acme.Foo
+                int idx = name.indexOf(INVOKER_SUFFIX);
+                if (idx != -1) {
+                    name = name.substring(0, idx);
+                }
+                if (name.contains(NESTED_SEPARATOR)) {
+                    name = name.replace(NESTED_SEPARATOR, "$");
+                }
+                return name;
+            }
+        });
 
         for (ScheduledBusinessMethodItem scheduledMethod : scheduledMethods) {
             ScheduledMethodMetadata metadata = new ScheduledMethodMetadata();
@@ -247,8 +269,8 @@ private String generateInvoker(ScheduledBusinessMethodItem scheduledMethod, Clas
 
         String baseName;
         if (bean.getImplClazz().enclosingClass() != null) {
-            baseName = DotNames.simpleName(bean.getImplClazz().enclosingClass()) + "_"
-                    + DotNames.simpleName(bean.getImplClazz().name());
+            baseName = DotNames.simpleName(bean.getImplClazz().enclosingClass()) + NESTED_SEPARATOR
+                    + DotNames.simpleName(bean.getImplClazz());
         } else {
             baseName = DotNames.simpleName(bean.getImplClazz().name());
         }

extensions/scheduler/runtime/src/main/java/io/quarkus/scheduler/Scheduled.java

@@ -15,6 +15,8 @@
 /**
  * Marks a business method to be automatically scheduled and invoked by the container.
  * <p>
+ * The target business method must be non-private and non-static.
+ * <p>
  * The schedule is defined either by {@link #cron()} or by {@link #every()} attribute. If both are specified, the cron
  * expression takes precedence.
  *