The port implements a factory method for the WSIFOperation interface.
Here is the Javadoc for the WSIFPort interface.
The createOperation(String) method returns a new instance of a WSIFOperation object. If the operationName value is not valid or the operation is overloaded, then the method throws an exception.
The createOperation(String, String, String) method supports overloaded WSDL operations. You can overload based on the input parameters, but not on the output parameters.
It is the duty of the client to call the close method when a port is no longer in use. In many cases, where the transport is sessionless, like HTTP, this has no effect. However, if the port is using a session-based protocol such as MQSeries, Java Messaging Service (JMS), or External Call Interface (ECI), this supports the port in caching an open connection to the server and then closing it as required. Responsibly-written applications will call the close method if appropriate.
See AlsoWSIF API reference: Using ports