Added appropriate synchronization around application event notification using the Spring ApplicationContext and ApplicationEventMulticaster. In addition, added support for late ContextRefreshedEvent notifications in the case where ApplicationListeners are registered after the ConfigurableApplicationContext has already been constructed, configured, initialized and refreshed. This latest feature is meant to support updates planned in the 7.5 GemFire release to the Gfsh 'deploy' command dynamically deploying and initializing Declarables in the JAR file. It is possible that Declarables are created and initialized in an unspecified order given there is not equivalent to Spring's Ordered interface in GemFire.

src/main/java/org/springframework/data/gemfire/support/SpringContextBootstrappingInitializer.java

@@ -66,7 +66,9 @@ public class SpringContextBootstrappingInitializer implements Declarable, Applic
 	/* package-private */ static volatile ConfigurableApplicationContext applicationContext;
 
 	// TODO consider whether I should register a TaskExecutor to perform the event notifications in a separate Thread???
-	private static ApplicationEventMulticaster eventNotifier = new SimpleApplicationEventMulticaster();
+	private static final ApplicationEventMulticaster eventNotifier = new SimpleApplicationEventMulticaster();
+
+	private static ContextRefreshedEvent contextRefreshedEvent;
 
 	/**
 	 * Gets a reference to the Spring ApplicationContext constructed, configured and initialized inside the GemFire
@@ -91,14 +93,41 @@ public class SpringContextBootstrappingInitializer implements Declarable, Applic
 	 * @return the reference to the ApplicationListener for method call chaining purposes.
 	 * @see #unregister(org.springframework.context.ApplicationListener)
 	 * @see org.springframework.context.ApplicationListener
+	 * @see org.springframework.context.event.ContextRefreshedEvent
 	 * @see org.springframework.context.event.SimpleApplicationEventMulticaster
 	 * 	#addApplicationListener(org.springframework.context.ApplicationListener)
 	 */
-	public static <T extends ApplicationListener> T register(final T listener) {
-		eventNotifier.addApplicationListener(listener);
+	public static <T extends ApplicationListener<ContextRefreshedEvent>> T register(final T listener) {
+		synchronized (eventNotifier) {
+			eventNotifier.addApplicationListener(listener);
+			notifyListenerOfExistingContextRefreshedEvent(listener);
+		}
+
 		return listener;
 	}
 
+	/**
+	 * Notifies any Spring ApplicationListeners of a current and existing ContextRefreshedEvent if the
+	 * ApplicationContext was previously created, initialized and refreshed before any ApplicationListeners interested
+	 * in ContextRefreshedEvents get registered so that application components (such as LazyWiringDeclarableSupport
+	 * objects) arriving late to the game that also require configuration (auto-wiring) get wired accordingly too.
+	 * <p/>
+	 * @param listener a Spring ApplicationListener requiring notification of any ContextRefreshedEvents after the
+	 * ApplicationContext has already been created, initialized and/or refreshed.
+	 * @see org.springframework.context.ApplicationListener#onApplicationEvent(org.springframework.context.ApplicationEvent)
+	 * @see org.springframework.context.event.ContextRefreshedEvent
+	 */
+	protected static void notifyListenerOfExistingContextRefreshedEvent(
+			final ApplicationListener<ContextRefreshedEvent> listener) {
+		synchronized (eventNotifier) {
+			// NOTE the null check on the ApplicationContext is not absolutely necessary, but is an extra safety
+			// precaution none-the-less.
+			if (applicationContext != null && contextRefreshedEvent != null) {
+				listener.onApplicationEvent(contextRefreshedEvent);
+			}
+		}
+	}
+
 	/**
 	 * Unregisters the Spring ApplicationListener from this SpringContextBootstrappingInitializer in order to stop
 	 * receiving ApplicationEvents on Spring context refreshes.
@@ -109,11 +138,15 @@ public class SpringContextBootstrappingInitializer implements Declarable, Applic
 	 * @return the reference to the ApplicationListener for method call chaining purposes.
 	 * @see #register(org.springframework.context.ApplicationListener)
 	 * @see org.springframework.context.ApplicationListener
+	 * @see org.springframework.context.event.ContextRefreshedEvent
 	 * @see org.springframework.context.event.SimpleApplicationEventMulticaster
 	 * 	#removeApplicationListener(org.springframework.context.ApplicationListener)
 	 */
-	public static <T extends ApplicationListener> T unregister(final T listener) {
-		eventNotifier.removeApplicationListener(listener);
+	public static <T extends ApplicationListener<ContextRefreshedEvent>> T unregister(final T listener) {
+		synchronized (eventNotifier) {
+			eventNotifier.removeApplicationListener(listener);
+		}
+
 		return listener;
 	}
 
@@ -131,7 +164,7 @@ public class SpringContextBootstrappingInitializer implements Declarable, Applic
 	 * @see org.springframework.context.support.ClassPathXmlApplicationContext
 	 */
 	protected ConfigurableApplicationContext createApplicationContext(final String[] configLocations) {
-		Assert.notEmpty(configLocations, "The configLocations must be specified to construct an instance"
+		Assert.notEmpty(configLocations, "'configLocations' must be specified to construct an instance"
 			+ " of the ClassPathXmlApplicationContext.");
 		return createApplicationContext(null, configLocations);
 	}
@@ -185,6 +218,7 @@ public class SpringContextBootstrappingInitializer implements Declarable, Applic
 	 * @see java.util.Properties
 	 */
 	@Override
+	@SuppressWarnings("null")
 	public void init(final Properties parameters) {
 		String basePackages = parameters.getProperty(BASE_PACKAGES_PARAMETER);
 		String contextConfigLocations = parameters.getProperty(CONTEXT_CONFIG_LOCATIONS_PARAMETER);
@@ -204,13 +238,15 @@ public class SpringContextBootstrappingInitializer implements Declarable, Applic
 					nullSafeGetApplicationContextId(applicationContext)));
 
 			applicationContext = createApplicationContext(basePackagesArray, configLocations);
+			Assert.notNull(applicationContext, "The 'created' ConfigurableApplicationContext cannot be null!");
 			applicationContext.addApplicationListener(this);
 			applicationContext.registerShutdownHook();
 			applicationContext.refresh();
 
 			Assert.state(applicationContext.isActive(), String.format(
-				"The Spring application context (%1$s) has failed to be properly initialized with the following config files (%2$s)!",
-					nullSafeGetApplicationContextId(applicationContext), Arrays.toString(configLocations)));
+				"The Spring application context (%1$s) has failed to be properly initialized with the following config files (%2$s) or base packages (%3$s)!",
+					nullSafeGetApplicationContextId(applicationContext), Arrays.toString(configLocations),
+						Arrays.toString(basePackagesArray)));
 		}
 	}
 
@@ -238,7 +274,10 @@ public class SpringContextBootstrappingInitializer implements Declarable, Applic
 	 */
 	@Override
 	public void onApplicationEvent(final ContextRefreshedEvent event) {
-		eventNotifier.multicastEvent(event);
+		synchronized (eventNotifier) {
+			contextRefreshedEvent = event;
+			eventNotifier.multicastEvent(event);
+		}
 	}
 
 }