Include test logic and configuration to terminate a (forked) Spring application so it does not run indefinitely.

spring-data-geode-test/src/main/java/org/springframework/data/gemfire/tests/integration/ForkingClientServerIntegrationTestsSupport.java

@@ -16,23 +16,34 @@
 package org.springframework.data.gemfire.tests.integration;
 
 import java.io.IOException;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Optional;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
 
 import org.junit.AfterClass;
 
 import org.apache.geode.cache.Cache;
 import org.apache.geode.cache.client.ClientCache;
 
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.event.ContextRefreshedEvent;
+import org.springframework.context.event.EventListener;
 import org.springframework.data.gemfire.config.annotation.CacheServerApplication;
 import org.springframework.data.gemfire.config.annotation.ClientCacheApplication;
 import org.springframework.data.gemfire.config.annotation.EnablePdx;
 import org.springframework.data.gemfire.tests.integration.config.ClientServerIntegrationTestsConfiguration;
 import org.springframework.data.gemfire.tests.process.ProcessWrapper;
 import org.springframework.data.gemfire.util.ArrayUtils;
+import org.springframework.data.gemfire.util.SpringUtils;
 import org.springframework.lang.NonNull;
 import org.springframework.lang.Nullable;
 
@@ -106,7 +117,7 @@ public abstract class ForkingClientServerIntegrationTestsSupport extends ClientS
 
 	@EnablePdx
 	@ClientCacheApplication(logLevel = GEMFIRE_LOG_LEVEL)
-	protected static class BaseGemFireClientConfiguration extends ClientServerIntegrationTestsConfiguration { }
+	public static class BaseGemFireClientConfiguration extends ClientServerIntegrationTestsConfiguration { }
 
 	@EnablePdx
 	@CacheServerApplication(name = "ForkingClientServerIntegrationTestsSupport", logLevel = GEMFIRE_LOG_LEVEL)
@@ -120,4 +131,71 @@ public abstract class ForkingClientServerIntegrationTestsSupport extends ClientS
 			applicationContext.registerShutdownHook();
 		}
 	}
+
+	@Configuration
+	public static class SpringApplicationTerminatorConfiguration {
+
+		@Bean
+		public SpringApplicationTerminatorConfigurer springApplicationTerminatorConfigurer() {
+			return SpringApplicationTerminatorConfigurer.EMPTY;
+		}
+
+		@EventListener(classes = ContextRefreshedEvent.class)
+		public void configureTerminator(@NonNull ContextRefreshedEvent event) {
+
+			Function<ApplicationContext, SpringApplicationTerminatorConfigurer> safeSpringApplicationTerminatorConfigurerResolver =
+				applicationContext -> SpringUtils.safeGetValue(() ->
+					applicationContext.getBean(SpringApplicationTerminatorConfigurer.class),
+						(SpringApplicationTerminatorConfigurer) null);
+
+			Runnable springApplicationTerminatorRunnable = () -> System.exit(-1);
+
+			ThreadFactory springApplicationTerminatorThreadFactory = runnable -> {
+
+				Thread springApplicationTerminatorThread =
+					new Thread(runnable, "Spring Application Terminator Thread");
+
+				springApplicationTerminatorThread.setDaemon(true);
+				springApplicationTerminatorThread.setPriority(Thread.NORM_PRIORITY);
+
+				return springApplicationTerminatorThread;
+			};
+
+			Optional.ofNullable(event)
+				.map(ContextRefreshedEvent::getApplicationContext)
+				.map(safeSpringApplicationTerminatorConfigurerResolver)
+				.filter(SpringApplicationTerminatorConfigurer::isNotEmpty)
+				.filter(this::delayIsGreaterThanZero)
+				.ifPresent(configurer ->
+					Executors.newScheduledThreadPool(1, springApplicationTerminatorThreadFactory)
+						.schedule(springApplicationTerminatorRunnable, configurer.delay().toMillis(),
+							TimeUnit.MILLISECONDS)
+				);
+		}
+
+		private boolean delayIsGreaterThanZero(@NonNull SpringApplicationTerminatorConfigurer configurer) {
+
+			return Optional.ofNullable(configurer)
+				.map(SpringApplicationTerminatorConfigurer::delay)
+				.map(delay -> Duration.ZERO.compareTo(delay) > 0)
+				.orElse(false);
+		}
+	}
+
+	public interface SpringApplicationTerminatorConfigurer {
+
+		SpringApplicationTerminatorConfigurer EMPTY = new SpringApplicationTerminatorConfigurer() { };
+
+		default boolean isEmpty() {
+			return EMPTY.equals(this);
+		}
+
+		default boolean isNotEmpty() {
+			return !isEmpty();
+		}
+
+		default Duration delay() {
+			return Duration.ZERO;
+		}
+	}
 }

spring-data-geode-test/src/test/java/org/springframework/data/gemfire/tests/integration/SpringApplicationTerminatingIntegrationTests.java

@@ -0,0 +1,112 @@
+/*
+ *  Copyright 2019 the original author or authors.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ *  or implied. See the License for the specific language governing
+ *  permissions and limitations under the License.
+ */
+package org.springframework.data.gemfire.tests.integration;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.IOException;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Scanner;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.context.annotation.Profile;
+import org.springframework.data.gemfire.tests.process.ProcessWrapper;
+
+/**
+ * Integration Tests testing and asserting Spring Application termination configuration.
+ *
+ * @author John Blum
+ * @see java.time.Duration
+ * @see java.time.Instant
+ * @see org.junit.Test
+ * @see org.springframework.context.annotation.AnnotationConfigApplicationContext
+ * @see org.springframework.context.annotation.Bean
+ * @see org.springframework.context.annotation.Configuration
+ * @see org.springframework.context.annotation.Import
+ * @see org.springframework.context.annotation.Profile
+ * @see org.springframework.data.gemfire.tests.process.ProcessWrapper
+ * @since 0.0.24
+ */
+@SuppressWarnings("unused")
+public class SpringApplicationTerminatingIntegrationTests extends ForkingClientServerIntegrationTestsSupport {
+
+	private static Instant startTime;
+
+	private static ProcessWrapper springApplicationProcess;
+
+	@BeforeClass
+	public static void startSpringApplication() throws IOException {
+
+		springApplicationProcess = run(TestSpringApplicationConfiguration.class,
+			"-Dspring.profiles.active=SpringApplicationTerminator");
+
+		startTime = Instant.now();
+	}
+
+	@AfterClass
+	public static void assertSpringApplicationTerminated() {
+
+		Condition springApplicationTerminatedCondition = () -> springApplicationProcess.isNotRunning();
+
+		waitOn(springApplicationTerminatedCondition, Duration.ofSeconds(10L).toMillis());
+
+		assertThat(Duration.between(startTime, Instant.now())).isGreaterThan(Duration.ofSeconds(5));
+	}
+
+	@Test
+	public void springApplicationIsRunning() {
+
+		assertThat(springApplicationProcess).isNotNull();
+		assertThat(springApplicationProcess.isAlive()).isTrue();
+		assertThat(springApplicationProcess.isRunning()).isTrue();
+	}
+
+	@Configuration
+	@Profile("SpringApplicationTerminator")
+	@Import(SpringApplicationTerminatorConfiguration.class)
+	static class TestSpringApplicationConfiguration {
+
+		public static void main(String[] args) {
+
+			AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext();
+
+			applicationContext.register(TestSpringApplicationConfiguration.class);
+			applicationContext.registerShutdownHook();
+
+			new Scanner(System.in).nextLine();
+		}
+
+		@Bean
+		SpringApplicationTerminatorConfigurer terminatorConfigurer() {
+
+			return new SpringApplicationTerminatorConfigurer() {
+
+				@Override
+				public Duration delay() {
+					return Duration.ofSeconds(5);
+				}
+			};
+		}
+	}
+}