public interface DoorService
{
    void open(Door door) throws DoorLockedException, DoorAlreadyOpenedException;

    void close(Door door) throws DoorAlreadyClosedException;

    /**
     * Closes the door if open
     */
    void lock(Door door) throws DoorAlreadyLockedException;
}

try
{
    doorService.lock(myDoor);
}
catch(DoorLockedException ex) // door ALREADY locked
{
    //error handling...
}