Tutorial week 5

1. The implementation of the file transfer client and server do not quite match the specification. What is the error? Correct the client and server to follow the specification
2. The number of times you can attempt to login is often limited.
   1. Modify the state transition diagram for file transfer with login to only allow three attempts before closing the connection
   2. Give two different implementations of this
3. Design and give UML diagrams for a client using Swing or AWT to use the file transfer client half object. Implement this if you wish.
4. Give XML DTDs for the other messages for a file transfer (if you already know about XML)