Jay, Lemme try and give a better explaination of what i mean. There's a difference between the "DNS name of server" in the allowed parameters and the java.rmi.server.hostname system property.
From the java documentation
java.rmi.server.hostname (1.1 and later) The value of this property represents the host name
string that should be associated with remote stubs for locally created remote objects, in order to allow clients to invoke methods on the remote object. In 1.1.7 and later, the default value of this property is the IP address of the local host, in "dotted-quad" format.
You will see that this 'system' parameter is required for the server only, so as to associate the stubs to the local objects. Since the value of this will always be localhost for the server, you don't really need to do this explicitly as this is the default.
However on the client who wants to connect to the remote server it would be incorrect to use the java.rmi.server.hostname since what you'd actually be telling the environment to do would be to associate any exported stubs to the specified server! In actuality you just want to pass the client the name of a remote system to connect to.
The latter is what is in the 'allowed' parameters list. A more correct way would be to pass as a parameter to the main method and handle from there.
Tina, Just for the record, I want you to know that you CAN set the properties from code using System.setProperty(...) method. Though I'm not exactly sure whether the settings will be made in time for them to be used correctly. The idea of leaving them on the command line is to allow your application to be run on any particular system without modifying your code. If the testers codebase is different from your's then the code won't run on his system! Best to leave most variable stuff on the command line.
About asking the user for details its a pretty good idea. Though I believe it would be better to provide both, since having to be prompted to enter the same data over and over again everytime a user wants to connect to the same data would be a real PAIN! (this is where command lines come in handy) Remember that part of the General Considerations marks comes from "ease of use" which has 23 marks. I provided both means in my own submission and got 57/58 in General Considerations.
Akanimo.