When i was working on a WIX, i encountered some issue in installing the application  (REST based webservice), my service is not started and later identified that the port number which i set in the application is already used by another application

To identify whether the port is in use, i used the Socket Class in Java, which is an endpoint for communication between two machines but i used for local machine to validate specified port
public Socket(String host, int port) throws UnknownHostException, IOException

if the host is null it will set the host as loopback address