airline
Class AirlineSystem.UserDB

java.lang.Object
  airline.AirlineSystem.UserDB

All Implemented Interfaces:

Serializable

Enclosing class:

AirlineSystem

private class AirlineSystem.UserDB
extends Object
implements Serializable

A container of existing system Users.

Author:

Michael Goldwasser

Field Summary

private HashMap<String,User>

map We maintain underlying collection as a HashMap

Constructor Summary

AirlineSystem.UserDB()
Creates an initially empty database.

Method Summary

void	add(User usr) Adds a User to the system.
User	getUser(String ID) Returns the User associated with the given ID.
Iterator<User>	iterator() Returns an iterator of User instances.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

map

private HashMap<String,User> map

We maintain underlying collection as a HashMap

Constructor Detail

AirlineSystem.UserDB

public AirlineSystem.UserDB()

Creates an initially empty database.

Method Detail

add

public void add(User usr)
         throws IllegalArgumentException

Adds a User to the system. The caller is responsible for ensuring that the new customer has been properly configured prior to entry into the system.

Parameters:

usr - the new User

Throws:

IllegalArgumentException - if system has existing customer with same ID.

getUser

public User getUser(String ID)

Returns the User associated with the given ID. Returns null if the ID is not found.

Parameters:

ID - The customer ID

Returns:

reference to the User instance; null if ID not found.

iterator

public Iterator<User> iterator()

Returns an iterator of User instances.

Returns:

Iterator of User instances;