Mancava la close!

tcp/TCPServer.java

@@ -34,7 +34,9 @@ class TCPServer {
 			capitalizedSentence = clientSentence.toUpperCase() + '\n'; 
 
 			/* Invia la risposta al client */
-			outToClient.writeBytes(capitalizedSentence); 
+			outToClient.writeBytes(capitalizedSentence);
+
+			connectionSocket.close();
 
 		}
 	}