INT-3794: SocketUtils - Bind to Loopback Adapter

JIRA: https://jira.spring.io/browse/INT-3794

On OSX, if a server socket is in use on the loopback adapter, but not on others,
a BindException is not thrown; instead the socket is bound to other adapters.

This causes test failures because tests, generally, expect the socket to be bound to localhost.

Change SocketUtils to attempt to bind to localhost.

Author: garyrussell

spring-integration-test/src/main/java/org/springframework/integration/test/util/SocketUtils.java

@@ -16,6 +16,7 @@
 package org.springframework.integration.test.util;
 
 import java.net.DatagramSocket;
+import java.net.InetAddress;
 import java.net.ServerSocket;
 import java.util.ArrayList;
 import java.util.List;
@@ -103,7 +104,8 @@ public static List<Integer> findAvailableServerSockets(int seed, int numberOfReq
 
 		for (int i = seed; i < seed+200; i++) {
 			try {
-				ServerSocket sock = ServerSocketFactory.getDefault().createServerSocket(i);
+				InetAddress ifAddress = InetAddress.getByName("localhost");
+				ServerSocket sock = ServerSocketFactory.getDefault().createServerSocket(i, 1, ifAddress);
 				sock.close();
 				openPorts.add(i);
 

spring-integration-test/src/test/java/org/springframework/integration/test/util/SocketUtilsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -15,12 +15,19 @@
  */
 package org.springframework.integration.test.util;
 
-import org.junit.Assert;
+import static org.junit.Assert.assertNotEquals;
+
+import java.net.InetAddress;
+import java.net.ServerSocket;
 
+import javax.net.ServerSocketFactory;
+
+import org.junit.Assert;
 import org.junit.Test;
 
 /**
  * @author Gunnar Hillert
+ * @author Gary Russell
  */
 public class SocketUtilsTests {
 
@@ -54,4 +61,13 @@ public void testFindAvailableUdpSocketWithNegativeSeedPort() {
 		Assert.fail("Expected an IllegalArgumentException to be thrown.");
 	}
 
+	@Test
+	public void testLocalhost() throws Exception {
+		int available = SocketUtils.findAvailableServerSocket();
+		InetAddress ifAddress = InetAddress.getByName("localhost");
+		ServerSocket ss = ServerSocketFactory.getDefault().createServerSocket(available, 1, ifAddress);
+		assertNotEquals(available, SocketUtils.findAvailableServerSocket(available));
+		ss.close();
+	}
+
 }