wcg.main

Class UserPool

java.lang.Object

wcg.main.UserPool

All Implemented Interfaces:

java.io.Serializable

public class UserPool
extends java.lang.Object
implements java.io.Serializable

A pool of system users with methods to add and retrieve them. Instances of this class are serializable to persist users in the file system. This class is a singleton.

Author:

José Paulo Leal jpleal@fc.up.pt

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
(package private) void	addUser(java.lang.String nick, java.lang.String password) Add an user with given nick and password.
(package private) static void	backup(UserPool pool) Save given pool in file.
static java.io.File	getBackupFile() Get the current file used for backup.
(package private) static UserPool	getInstance() Single instance of this class.
(package private) User	getUser(java.lang.String nick, java.lang.String password) Retrieve the user with given nick if it authenticates with given password.
(package private) void	reset() Resets UserPool's fields to enable unit testing on the Manager singleton.
(package private) static UserPool	restore() Restore backup file and return saved pool.
static void	setBackupFile(java.io.File backupFile) Change the file used for backups.
static void	setBackupFile(java.lang.String name) Convenience method to set the backup file as a string

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

static UserPool getInstance()
                     throws CardGameException

Single instance of this class. If a backup is available then the instance is recovered from a file.

Returns:

single instance.

Throws:

CardGameException - on error restoring backup file.

getBackupFile

public static java.io.File getBackupFile()

Get the current file used for backup. It is an absolute pathname

Returns:

backup file.

setBackupFile

public static void setBackupFile(java.io.File backupFile)

Change the file used for backups. This file is persisted as an absolute pathname, even if given as a relative pathname

Parameters:

backupFile - to save the serialization.

setBackupFile

public static void setBackupFile(java.lang.String name)

Convenience method to set the backup file as a string

Parameters:

name - of backup file.

backup

static void backup(UserPool pool)
            throws CardGameException

Save given pool in file.

Parameters:

pool - to save.

Throws:

CardGameException - if backup file is not writable or I/O error occurs during writing.

restore

static UserPool restore()
                 throws CardGameException

Restore backup file and return saved pool.

Returns:

user pool or null if not available

Throws:

CardGameException - if backup file is not readable or I/O error occurs during reading

getUser

User getUser(java.lang.String nick,
             java.lang.String password)
      throws CardGameException

Retrieve the user with given nick if it authenticates with given password.

Parameters:

nick - of user.

password - of user.

Returns:

user.

Throws:

CardGameException - nick or password are invalid.

addUser

void addUser(java.lang.String nick,
             java.lang.String password)
      throws CardGameException

Add an user with given nick and password. Neither argument can have a null value.

Parameters:

nick - of user.

password - of user.

Throws:

CardGameException - if any of the arguments is null.

reset

void reset()

Resets UserPool's fields to enable unit testing on the Manager singleton. This method must only be used during testing and shoudn't be public.