Why am I getting the port number -1 when I use the getPort() method of URL?
Created May 4, 2012
Tim Rohaly A URL doesn't imply a socket connection to a resource - it
is just a string representation telling you where that resource
can be found on the network. In particular, in order to determine
the "port", the URL class simply parses the URL string that you
specified in the constructor. Since the "port" field of a URL
is optional, getPort() returns -1 in the case where
the port was not explicitly specified.
For example, this code:
URL url = new URL("http://www.jguru.com/");
System.out.println("Port = " + url.getPort());
will print "Port = -1" because there is no port specified
in the given URL (you can assume it uses the default
port number for that protocol). However, this other
code:
URL url = new URL("http://www.jguru.com:80/");
System.out.println("Port = " + url.getPort());
will print "Port = 80" because the port was explicit
in the URL.