INT-2154 Minor Refactoring

Factor out socket creation to a protected method, to facilitate
easier subclassing, enabling something other than the default
Socket factories to be used.

spring-integration-ip/src/main/java/org/springframework/integration/ip/tcp/connection/TcpNetClientConnectionFactory.java

@@ -16,6 +16,7 @@
 
 package org.springframework.integration.ip.tcp.connection;
 
+import java.io.IOException;
 import java.net.Socket;
 
 import javax.net.SocketFactory;
@@ -48,7 +49,7 @@ public class TcpNetClientConnectionFactory extends
 			return this.theConnection;
 		}
 		logger.debug("Opening new socket connection to " + this.host + ":" + this.port);
-		Socket socket = SocketFactory.getDefault().createSocket(this.host, this.port);
+		Socket socket = createSocket(this.host, this.port);
 		setSocketAttributes(socket);
 		TcpConnection connection = new TcpNetConnection(socket, false, this.isLookupHost());
 		connection = wrapConnection(connection);
@@ -61,6 +62,19 @@ public class TcpNetClientConnectionFactory extends
 		return connection;
 	}
 
+	/**
+	 * Create a new {@link Socket}. This default implementation uses the default
+	 * {@link SocketFactory}. Override to use some other mechanism
+	 *
+	 * @param host The host.
+	 * @param port The port.
+	 * @return The Socket
+	 * @throws IOException
+	 */
+	protected Socket createSocket(String host, int port) throws IOException {
+		return SocketFactory.getDefault().createSocket(host, port);
+	}
+
 	public void close() {
 	}
 

spring-integration-ip/src/main/java/org/springframework/integration/ip/tcp/connection/TcpNetServerConnectionFactory.java

@@ -58,14 +58,12 @@ public class TcpNetServerConnectionFactory extends AbstractServerConnectionFacto
 		}
 		try {
 			if (this.localAddress == null) {
-				this.serverSocket = ServerSocketFactory.getDefault()
-						.createServerSocket(this.port, Math.abs(this.poolSize));
+				theServerSocket = createServerSocket(this.port, this.poolSize, null);
 			} else {
 				InetAddress whichNic = InetAddress.getByName(this.localAddress);
-				this.serverSocket = ServerSocketFactory.getDefault()
-						.createServerSocket(port, Math.abs(poolSize), whichNic);
+				theServerSocket = createServerSocket(this.port, this.poolSize, whichNic);
 			}
-			theServerSocket = this.serverSocket;
+			this.serverSocket = theServerSocket;
 			this.listening = true;
 			logger.info("Listening on port " + this.port);
 			while (true) {
@@ -90,6 +88,27 @@ public class TcpNetServerConnectionFactory extends AbstractServerConnectionFacto
 		}
 	}
 
+	/**
+	 * Create a new {@link ServerSocket}. This default implementation uses the default
+	 * {@link ServerSocketFactory}. Override to use some other mechanism
+	 *
+	 * @param port The port.
+	 * @param backlog The server socket backlog.
+	 * @param whichNic An InetAddress if binding to a specific network interface. Set to
+	 * null when configured to bind to all interfaces.
+	 * @return The Server Socket.
+	 * @throws IOException
+	 */
+	protected ServerSocket createServerSocket(int port, int backlog, InetAddress whichNic) throws IOException {
+		if (whichNic == null) {
+			return ServerSocketFactory.getDefault().createServerSocket(port,
+					Math.abs(poolSize));
+		} else {
+			return ServerSocketFactory.getDefault().createServerSocket(port,
+					Math.abs(poolSize), whichNic);
+		}
+	}
+
 	public boolean isRunning() {
 		return this.active;
 	}