fix(server): expose event processor startup

Author: kabir

docs/content/dev/server.md

@@ -247,4 +247,36 @@ See [Backward Compatibility](compatibility) for multi-version modules, version r
 - **Quarkus** — Reference implementations are Quarkus-based (JSON-RPC, gRPC, REST)
 - **Jakarta EE** — [a2a-jakarta](https://github.com/wildfly-extras/a2a-jakarta) works with any Jakarta EE Web Profile runtime
 
+### Manual Wiring
+
+For example, when wiring the server components as Spring beans, expose the event processor as a bean and pass it to the request handler. The handler starts the processor when it is constructed, including when the processor was created manually:
+
+```java
+@Configuration
+class A2AServerConfiguration {
+
+    @Bean
+    MainEventBus mainEventBus() {
+        return new MainEventBus();
+    }
+
+    @Bean
+    MainEventBusProcessor mainEventBusProcessor(MainEventBus mainEventBus, TaskStore taskStore,
+                                                PushNotificationSender pushSender, QueueManager queueManager) {
+        return new MainEventBusProcessor(mainEventBus, taskStore, pushSender, queueManager);
+    }
+
+    @Bean
+    RequestHandler requestHandler(AgentExecutor agentExecutor, TaskStore taskStore,
+                                  QueueManager queueManager, PushNotificationConfigStore pushConfigStore,
+                                  MainEventBusProcessor mainEventBusProcessor,
+                                  @Qualifier("a2aInternal") Executor executor) {
+        return new DefaultRequestHandler(agentExecutor, taskStore, queueManager, pushConfigStore,
+                mainEventBusProcessor, executor, executor);
+    }
+}
+```
+
+This assumes the other method parameters are also registered as Spring beans. The same executor is passed for agent execution and event consumption, as in this example; applications can provide separate executors when needed.
+
 See [CONTRIBUTING_INTEGRATIONS.md](https://github.com/a2aproject/a2a-java/blob/main/CONTRIBUTING_INTEGRATIONS.md) to submit your own integration.

server-common/src/main/java/org/a2aproject/sdk/server/events/MainEventBusProcessor.java

@@ -158,7 +158,7 @@ int pushNotificationChainCount() {
 
     @SuppressWarnings("NullAway.Init")
     @PostConstruct
-    synchronized void start() {
+    public synchronized void start() {
         if (processorThread != null && processorThread.isAlive()) {
             LOGGER.debug("MainEventBusProcessor already started");
             return;
@@ -170,17 +170,6 @@ synchronized void start() {
         LOGGER.info("MainEventBusProcessor started");
     }
 
-    /**
-     * Ensures the background processor thread has been started.
-     * <p>
-     * In CDI runtimes, this forces proxy resolution and {@link PostConstruct}. For manual
-     * wiring, this starts the processor directly.
-     * </p>
-     */
-    public void ensureStarted() {
-        start();
-    }
-
     @PreDestroy
     synchronized void stop() {
         LOGGER.info("MainEventBusProcessor stopping...");

server-common/src/main/java/org/a2aproject/sdk/server/events/MainEventBusProcessorInitializer.java

@@ -27,14 +27,12 @@ public class MainEventBusProcessorInitializer {
 
     /**
      * Observes ApplicationScoped initialization to force eager creation of MainEventBusProcessor.
-     * The injection of MainEventBusProcessor in this bean triggers its creation, and calling
-     * ensureStarted() forces the CDI proxy to be resolved, which ensures @PostConstruct has been
+     * Calling start() forces the CDI proxy to be resolved, which ensures @PostConstruct has been
      * called and the background thread is running.
      */
     void onStart(@Observes @Initialized(ApplicationScoped.class) Object event) {
         if (processor != null) {
-            // Force proxy resolution to ensure @PostConstruct has been called
-            processor.ensureStarted();
+            processor.start();
             LOGGER.info("MainEventBusProcessor initialized and started");
         } else {
             LOGGER.error("MainEventBusProcessor is null - initialization failed!");