Fix bug with reuse of closed sockets

src/tools/HostItem.java

@@ -32,7 +32,7 @@ public class HostItem {
 	 * @return	TCP Socket
 	 */
 	public Socket getTCPSocket() {
-		if (tcpSocket == null) {
+		if (tcpSocket == null || tcpSocket.isClosed()) {
 			try {
 				tcpSocket = new Socket(InetAddress.getByName(hostname), port);
 			} catch (SocketException e) {
@@ -56,7 +56,7 @@ public class HostItem {
 	 * @throws	IOException
 	 */
 	public Socket tryGetTCPSocket() throws SocketException, UnknownHostException, IOException {
-		if (tcpSocket == null) {
+		if (tcpSocket == null || tcpSocket.isClosed()) {
 			tcpSocket = new Socket(InetAddress.getByName(hostname), port);
 		}
 		return tcpSocket;
@@ -79,7 +79,7 @@ public class HostItem {
 	 * return	UDP Socket
 	 */
 	public DatagramSocket getUDPSocket() {
-		if (udpSocket == null) {
+		if (udpSocket == null || udpSocket.isClosed()) {
 			try {
 				udpSocket = new DatagramSocket();
 				udpSocket.connect(InetAddress.getByName(hostname), port);