Improve Multi-Site (WAN) Caching Sample Integration Tests resiliency.

Include an additional Spring @Configuration class exclusively for testing that registers a Geode CacheListener to wait for the cache Region EntryEvent to occur.  When the ClientCache Registers Interest (all keys) and receives the cache Region (CustomersByName) EntryEvent, then it signifies the WAN Gateways (Sender and Receiver) has replicated the Region EntryEvent between disparate sites.  Client 1 creates the Region EntryEvent that Client 2 expects to see in its cache.

Resolves gh-80.

spring-geode-samples/caching/multi-site/src/test/java/example/app/caching/multisite/MultiSiteCachingIntegrationTests.java

@@ -19,18 +19,36 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 import java.io.IOException;
 import java.time.Duration;
+import java.util.Collections;
 import java.util.Optional;
 import java.util.Properties;
+import java.util.Set;
 
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
+import org.apache.geode.cache.CacheListener;
+import org.apache.geode.cache.EntryEvent;
+import org.apache.geode.cache.InterestResultPolicy;
+import org.apache.geode.cache.util.CacheListenerAdapter;
+
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.builder.SpringApplicationBuilder;
 import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.gemfire.client.ClientRegionFactoryBean;
+import org.springframework.data.gemfire.client.Interest;
+import org.springframework.data.gemfire.client.RegexInterest;
+import org.springframework.data.gemfire.config.annotation.ClientCacheConfigurer;
+import org.springframework.data.gemfire.config.annotation.RegionConfigurer;
 import org.springframework.data.gemfire.tests.integration.ForkingClientServerIntegrationTestsSupport;
 import org.springframework.data.gemfire.tests.process.ProcessWrapper;
+import org.springframework.data.gemfire.util.ArrayUtils;
+import org.springframework.data.gemfire.util.CollectionUtils;
+import org.springframework.lang.NonNull;
 
 import example.app.caching.multisite.client.BootGeodeMultiSiteCachingClientApplication;
 import example.app.caching.multisite.client.model.Customer;
@@ -64,6 +82,7 @@ public class MultiSiteCachingIntegrationTests extends ForkingClientServerIntegra
 	private static ProcessWrapper geodeClusterTwo;
 
 	private static final String HOSTNAME = "localhost";
+	private static final String TEST_CUSTOMER_NAME = "Jon Doe";
 
 	@BeforeClass
 	public static void startGeodeClusters() throws IOException {
@@ -95,6 +114,11 @@ public class MultiSiteCachingIntegrationTests extends ForkingClientServerIntegra
 	}
 
 	private ConfigurableApplicationContext newApplicationContext(int locatorPort, String... springProfiles) {
+		return newApplicationContext(locatorPort, Collections.emptySet(), springProfiles);
+	}
+
+	private ConfigurableApplicationContext newApplicationContext(int locatorPort, Set<Class<?>> sources,
+			String... springProfiles) {
 
 		Properties configuration = new Properties();
 
@@ -109,6 +133,7 @@ public class MultiSiteCachingIntegrationTests extends ForkingClientServerIntegra
 				.headless(true)
 				.profiles(springProfiles)
 				//.properties(configuration)
+				.sources(CollectionUtils.nullSafeSet(sources).toArray(new Class[0]))
 				.registerShutdownHook(true)
 				.build();
 
@@ -135,6 +160,7 @@ public class MultiSiteCachingIntegrationTests extends ForkingClientServerIntegra
 
 			assertThat(applicationContext).isNotNull();
 			assertThat(applicationContext.isActive()).isTrue();
+			assertThat(applicationContext.isRunning()).isTrue();
 
 			CustomerService customerService = applicationContext.getBean(CustomerService.class);
 
@@ -150,10 +176,19 @@ public class MultiSiteCachingIntegrationTests extends ForkingClientServerIntegra
 
 			close(applicationContext);
 
-			applicationContext = newApplicationContext(locatorPortClusterTwo, "client-site2");
+			applicationContext = newApplicationContext(locatorPortClusterTwo,
+				Collections.singleton(TestGeodeClientConfiguration.class), "client-site2");
 
 			assertThat(applicationContext).isNotNull();
 			assertThat(applicationContext.isActive()).isTrue();
+			assertThat(applicationContext.isRunning()).isTrue();
+
+			CustomersByNameCacheListener customersByNameCacheListener =
+				applicationContext.getBean("customersByNameCacheListener", CustomersByNameCacheListener.class);
+
+			assertThat(customersByNameCacheListener).isNotNull();
+
+			ThreadUtils.waitFor(Duration.ofSeconds(10), 500L, customersByNameCacheListener::isEntryEventArrived);
 
 			customerService = applicationContext.getBean(CustomerService.class);
 			customerService.setSleepInSeconds(2L);
@@ -169,4 +204,66 @@ public class MultiSiteCachingIntegrationTests extends ForkingClientServerIntegra
 			close(applicationContext);
 		}
 	}
+
+	@SuppressWarnings("unused")
+	static class CustomersByNameCacheListener extends CacheListenerAdapter<String, Customer> {
+
+		private boolean entryEventArrived = false;
+
+		@Override
+		public synchronized void afterCreate(EntryEvent<String, Customer> event) {
+
+			this.entryEventArrived |= Optional.ofNullable(event)
+				//.map(this::log)
+				.map(EntryEvent::getKey)
+				.filter(TEST_CUSTOMER_NAME::equals)
+				.isPresent();
+		}
+
+		synchronized boolean isEntryEventArrived() {
+			return this.entryEventArrived;
+		}
+
+		@NonNull EntryEvent<String, Customer> log(@NonNull EntryEvent<String, Customer> entryEvent) {
+
+			System.err.printf("EntryEvent with key [%s] and value [%s] arrived for Region [%s]%n",
+				entryEvent.getKey(), entryEvent.getNewValue(), entryEvent.getRegion().getName());
+
+			return entryEvent;
+		}
+	}
+
+	@Configuration
+	@SuppressWarnings("unused")
+	static class TestGeodeClientConfiguration {
+
+		@Bean
+		ClientCacheConfigurer clientCacheSubscriptionsEnabledConfigurer() {
+			return (beanName, bean) -> bean.setSubscriptionEnabled(true);
+		}
+
+		@Bean
+		@SuppressWarnings({ "rawtypes", "unchecked" })
+		RegionConfigurer customersByNameCacheListenerConfigurer(@Qualifier("customersByNameCacheListener")
+				CacheListener<String, Customer> customersByNameCacheListener) {
+
+			return new RegionConfigurer() {
+
+				@Override
+				public void configure(String beanName, ClientRegionFactoryBean<?, ?> bean) {
+
+					if ("CustomersByName".equals(beanName)) {
+						bean.setCacheListeners(ArrayUtils.<CacheListener>asArray(customersByNameCacheListener));
+						bean.setInterests(ArrayUtils.<Interest>asArray(new RegexInterest(".*",
+							InterestResultPolicy.KEYS, false, false)));
+					}
+				}
+			};
+		}
+
+		@Bean
+		CacheListener<String, Customer> customersByNameCacheListener() {
+			return new CustomersByNameCacheListener();
+		}
+	}
 }