Add utility method to find and reserve allocated network ports.

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

@@ -24,9 +24,13 @@ import java.net.InetSocketAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
 import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.ConcurrentSkipListSet;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 
+import org.junit.AfterClass;
+
 import org.apache.geode.cache.server.CacheServer;
 
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
@@ -66,6 +70,13 @@ public abstract class ClientServerIntegrationTestsSupport extends IntegrationTes
 	protected static final String DEBUGGING_ENABLED_PROPERTY = "spring.data.gemfire.test.debugging.enabled";
 	protected static final String PROCESS_RUN_MANUAL_PROPERTY = "spring.data.gemfire.test.process.run-manual";
 
+	private static final Set<Integer> allocatedPorts = new ConcurrentSkipListSet<>();
+
+	@AfterClass
+	public static void deallocatePorts() {
+		allocatedPorts.clear();
+	}
+
 	protected static int findAvailablePort() throws IOException {
 
 		ServerSocket serverSocket = null;
@@ -82,6 +93,18 @@ public abstract class ClientServerIntegrationTestsSupport extends IntegrationTes
 		}
 	}
 
+	protected static int findAndReserveAvailablePort() throws IOException {
+
+		int availablePort = 0;
+
+		do {
+			availablePort = findAvailablePort();
+		}
+		while (!allocatedPorts.add(availablePort));
+
+		return availablePort;
+	}
+
 	protected static int intValue(Number number) {
 		return number != null ? number.intValue() : 0;
 	}

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

@@ -0,0 +1,49 @@
+/*
+ *  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.util.HashSet;
+import java.util.Set;
+
+import org.junit.Test;
+
+/**
+ * Integration Tests for {@link ClientServerIntegrationTestsSupport}.
+ *
+ * @author John Blum
+ * @see org.junit.Test
+ * @see org.springframework.data.gemfire.tests.integration.ClientServerIntegrationTests
+ * @since 0.0.14.RELEASE
+ */
+public class ClientServerIntegrationTestsSupportTests extends ClientServerIntegrationTestsSupport {
+
+	@Test
+	public void allocatedPortsAreDifferent() throws IOException {
+
+		int expectedSize = 3;
+
+		Set<Integer> allocatedPorts = new HashSet<>();
+
+		for (int index = 0; index < expectedSize; index++) {
+			allocatedPorts.add(findAndReserveAvailablePort());
+		}
+
+		assertThat(allocatedPorts).hasSize(expectedSize);
+	}
+}