userDatabase
Class UserDatabaseController

java.lang.Object
  userDatabase.UserDatabaseController

All Implemented Interfaces:

UserDatabaseInterface

public class UserDatabaseController
extends java.lang.Object
implements UserDatabaseInterface

Controller class of component UserDatabase. Implements the architecture interface UserDatabaseInterface.

Used to store user-specific data (e. g. identifiers, session keys and buffers).

Author:

Karl-Peter Fuchs

Nested Class Summary

private class

UserDatabaseController.cleanDatabaseTask Simple TimerTask, which calls cleanDatabase().

Field Summary

private int	INACTIVITY_TIMEOUT Period of time without actions, after which a channel is considered as inactive.
private static InternalInformationPortController	internalInformationPort Reference on component InternalInformationPort.
private java.util.Hashtable<java.lang.Integer,User>	localUserIDs Hashtable containing references on all available Users, retrievable via a local user identifier (Integer).
private static java.util.logging.Logger	LOGGER Logger used to log and display information.
private java.util.Hashtable<java.lang.Integer,User>	nextMixUserIDs Hashtable containing references on all available Users, retrievable via a the next mix' user identifier (Integer).

Constructor Summary

UserDatabaseController()
Generates a new UserDatabase component.

Method Summary

void	addUser(User user) Adds the bypassed User to the internal database.
private void	cleanDatabase() Removes Users from the internal database that were inactive for at least INACTIVITY_TIMEOUT ms.
java.util.Collection<User>	getActiveUsers() Returns all Users that are currently active.
int	getSize() Returns the number of Users currently stored in the internal database.
User	getUser(int identifier) Returns the User with the bypassed identifier.
User	getUserByNextMixIdentifier(int nextMixIdentifier) Returns the User with the bypassed identifier.
void	initialize() Initializes the this component.
boolean	isExistingUser(int identifier) Returns whether a User with the bypassed identifier is present in the internal database or not.
void	removeUser(int identifier) Removes the User with the bypassed identifier.

Methods inherited from class java.lang.Object

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

Field Detail

internalInformationPort

private static InternalInformationPortController internalInformationPort

Reference on component InternalInformationPort. Used to display and/or log data and read general settings.

LOGGER

private static final java.util.logging.Logger LOGGER

Logger used to log and display information.

INACTIVITY_TIMEOUT

private final int INACTIVITY_TIMEOUT

Period of time without actions, after which a channel is considered as inactive.

localUserIDs

private java.util.Hashtable<java.lang.Integer,User> localUserIDs

Hashtable containing references on all available Users, retrievable via a local user identifier (Integer).

nextMixUserIDs

private java.util.Hashtable<java.lang.Integer,User> nextMixUserIDs

Hashtable containing references on all available Users, retrievable via a the next mix' user identifier (Integer).

Note: The identifier differs from mix to mix to prevent linkability.

Constructor Detail

UserDatabaseController

public UserDatabaseController()

Generates a new UserDatabase component.

Used to store user-specific data (e. g. identifiers, session keys and buffers).

Method Detail

initialize

public void initialize()

Initializes the this component.

addUser

public void addUser(User user)
             throws UserAlreadyExistingException

Adds the bypassed User to the internal database.

Specified by:

addUser in interface UserDatabaseInterface

Parameters:

user - The User to be added.

Throws:

UserAlreadyExistingException - Thrown when the bypassed User has already been added (user's identifier already in use).

getSize

public int getSize()

Returns the number of Users currently stored in the internal database.

Specified by:

getSize in interface UserDatabaseInterface

Returns:

Number of Users currently stored in the internal database.

getUser

public User getUser(int identifier)
             throws UnknownUserException

Returns the User with the bypassed identifier.

Specified by:

getUser in interface UserDatabaseInterface

Parameters:

identifier - Identifier of the User to be returned.

Returns:

User with the bypassed identifier.

Throws:

UnknownUserException - Thrown when no User with the bypassed identifier is existent.

isExistingUser

public boolean isExistingUser(int identifier)

Returns whether a User with the bypassed identifier is present in the internal database or not.

Specified by:

isExistingUser in interface UserDatabaseInterface

Parameters:

identifier - Identifier to search for.

Returns:

User present or not.

removeUser

public void removeUser(int identifier)
                throws UnknownUserException

Removes the User with the bypassed identifier.

Specified by:

removeUser in interface UserDatabaseInterface

Parameters:

identifier - Identifier of the User to be removed from the internal database.

Throws:

UnknownUserException - Thrown when no User with the bypassed identifier is existent.

getUserByNextMixIdentifier

public User getUserByNextMixIdentifier(int nextMixIdentifier)
                                throws UnknownUserException

Returns the User with the bypassed identifier.

Specified by:

getUserByNextMixIdentifier in interface UserDatabaseInterface

Parameters:

nextMixIdentifier - Identifier of the User to be returned.

Returns:

User with the bypassed identifier.

Throws:

UnknownUserException - Thrown when no User with the bypassed identifier is existent.

getActiveUsers

public java.util.Collection<User> getActiveUsers()

Returns all Users that are currently active.

Specified by:

getActiveUsers in interface UserDatabaseInterface

Returns:

Collection of all Users currently active.

cleanDatabase

private void cleanDatabase()

Removes Users from the internal database that were inactive for at least INACTIVITY_TIMEOUT ms.

See Also:

INACTIVITY_TIMEOUT