uk.ac.starlink.auth

Class UserInterface

java.lang.Object

uk.ac.starlink.auth.UserInterface

public abstract class UserInterface
extends Object

Abstraction via which authentication classes can acquire credentials from the user.

Since:

15 Jun 2020

Author:

Mark Taylor

Field Summary

Fields

Modifier and Type	Field and Description
static UserInterface	CLI Command-line instance.
static UserInterface	GUI Instance that uses Swing popup dialogues.
static UserInterface	NO_AUTH Instance that will not authenticate.
static String	PASSWORD_PROP Name of password system property for headless UI instance ("auth.password").
static String	USERNAME_PROP Name of username system property for headless UI instance ("auth.username").

Constructor Summary

Constructors

Constructor and Description
UserInterface()

Method Summary

Modifier and Type	Method and Description
abstract boolean	canRetry() Indicates whether there is any point in repeated attempts to acquire credentials from the user.
static JComponent	createAuthPanel(String[] msgLines, JTextField userField, JPasswordField passField) Places the components for acquiring username and password.
static UserInterface	createFixed(String username, String password) Returns a headless implementation with a fixed user name and password supplied as strings.
static UserInterface	createFixed(UserPass userpass) Returns a headless implementation with a fixed username+password object.
Component	getParent() Returns the GUI component to which this UI is subordinate.
static UserInterface	getPropertiesUi() Returns a headless UI that takes username and password from the system properties USERNAME_PROP and PASSWORD_PROP respectively, if both properties are set.
static UserInterface	getPropertiesUi(String userProp, String passProp) Returns a headless UI that takes username and password from two named System Properties.
abstract void	message(String[] lines) Sends a message to the user.
abstract UserPass	readUserPassword(String[] msgLines) Returns a username/password pair, or null if the user declines to supply one.
void	setParent(Component parent) Sets a GUI component to which this UI is subordinate.

Methods inherited from class java.lang.Object

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

Field Detail

CLI

public static final UserInterface CLI

Command-line instance.

GUI

public static final UserInterface GUI

Instance that uses Swing popup dialogues.

NO_AUTH

public static final UserInterface NO_AUTH

Instance that will not authenticate.

USERNAME_PROP

public static final String USERNAME_PROP

Name of username system property for headless UI instance ("auth.username").

See Also:

Constant Field Values

PASSWORD_PROP

public static final String PASSWORD_PROP

Name of password system property for headless UI instance ("auth.password").

See Also:

Constant Field Values

Constructor Detail

UserInterface

public UserInterface()

Method Detail

readUserPassword

public abstract UserPass readUserPassword(String[] msgLines)

Returns a username/password pair, or null if the user declines to supply one.

Parameters:

msgLines - message to output to the user first

Returns:

credentials, or null if the user declines

message

public abstract void message(String[] lines)

Sends a message to the user. In the case of a GUI this will typically provoke a popup window, so it should not be used gratitously.

Parameters:

lines - message to pass to the user

canRetry

public abstract boolean canRetry()

Indicates whether there is any point in repeated attempts to acquire credentials from the user. In an interactive context, this would typically return true, but in a headless context with preset credentials that will not change between invocations, it should return false.

Returns:

true if repeated requests may return different results

setParent

public void setParent(Component parent)

Sets a GUI component to which this UI is subordinate. For non-GUI implementations, this method is likely to have no effect, but for GUI-based implementations, it can be used to manage the ownership of popup dialogues.

Parameters:

parent - new parent component, may be null

getParent

public Component getParent()

Returns the GUI component to which this UI is subordinate. Likely to be irrelevant for non-GUI implementations.

Returns:

parent component, may be null

createFixed

public static UserInterface createFixed(String username,
                                        String password)

Returns a headless implementation with a fixed user name and password supplied as strings.

Parameters:

username - username

password - password

Returns:

headless instance

createFixed

public static UserInterface createFixed(UserPass userpass)

Returns a headless implementation with a fixed username+password object.

Parameters:

userpass - credentials object

Returns:

headless instance

getPropertiesUi

public static UserInterface getPropertiesUi()

Returns a headless UI that takes username and password from the system properties USERNAME_PROP and PASSWORD_PROP respectively, if both properties are set.

If the first character of either property value is "@", the remainder is interpreted as a filename containing the value.

Use the result of this method with care, since it risks leaking credentials to sites for which they are not intended.

This is a shortcut for getPropertiesUi(USERNAME_PROP, PASSWORD_PROP).

Returns:

new headless UserInterface instance, or null if not both properties are set

getPropertiesUi

public static UserInterface getPropertiesUi(String userProp,
                                            String passProp)

Returns a headless UI that takes username and password from two named System Properties. If the system properties, read at the time of this invocation, have not been defined, then null is returned.

If the first character of either property value is "@", the remainder is interpreted as a filename containing the value.

Use the result of this method with care, since it risks leaking credentials to sites for which they are not intended.

Parameters:

userProp - system property name for acquiring username

passProp - system property name for acquiring password

Returns:

new headless UserInterface instance, or null if not both properties are set

createAuthPanel

public static JComponent createAuthPanel(String[] msgLines,
                                         JTextField userField,
                                         JPasswordField passField)

Places the components for acquiring username and password.

Parameters:

msgLines - message to display to user

userField - field for username

passField - field for password