opencard.core.terminal
Interface Pollable
- public abstract interface Pollable
This interface must be implemented by implementations of
CardTerminal
if they do not generate events when a
card is inserted in or removed from the card terminal.
Method Summary |
void |
poll()
Checks the status of the underlying terminal device. |
poll
public void poll()
throws CardTerminalException
- Checks the status of the underlying terminal device. Must generate
a CardTerminalEvent if a card is being inserted or removed
by calling CardTerminal.cardInserted() or CardTerminal.cardRemoved().
Alternatively the terminal could perform status checks itsself, e.g.
by handling interrupts.
Implementation Note: the CardTerminalRegistry calls
this method of all registered Pollable terminals periodically.
So the implementation of this method should not carry out
lengthy operations but return as quickly as possible.
- Throws:
- CardTerminalException - Thrown when error occurred in poll-mechanism.