java.net
Class Authenticator

java.lang.Object
  extended by java.net.Authenticator

public abstract class Authenticator
extends Object

This abstract class provides a model for obtaining authentication information (in the form of a username and password) required by some network operations (such as hitting a password protected web site).

To make use of this feature, a programmer must create a subclass that knows how to obtain the necessary info. An example would be a class that popped up a dialog box to prompt the user. After creating an instance of that subclass, the static setDefault method of this class is called to set up that instance as the object to use on subsequent calls to obtain authorization.

Since:
1.2

Constructor Summary
Authenticator()
          Default, no-argument constructor for subclasses to call.
 
Method Summary
protected  PasswordAuthentication getPasswordAuthentication()
          This method is called whenever a request for authentication is made.
protected  String getRequestingHost()
          Returns the hostname of the host or proxy requesting authorization, or null if not available.
protected  int getRequestingPort()
          This method returns the port of the site that is requesting authentication.
protected  String getRequestingPrompt()
          Returns the prompt that should be used when requesting authentication information from the user
protected  String getRequestingProtocol()
          This method returns the requesting protocol of the operation that is requesting authentication
protected  String getRequestingScheme()
          This method returns the authentication scheme in use
protected  InetAddress getRequestingSite()
          This method returns the address of the site that is requesting authentication.
static PasswordAuthentication requestPasswordAuthentication(InetAddress addr, int port, String protocol, String prompt, String scheme)
          This method is called whenever a username and password for a given network operation is required.
static PasswordAuthentication requestPasswordAuthentication(String host, InetAddress addr, int port, String protocol, String prompt, String scheme)
          This method is called whenever a username and password for a given network operation is required.
static void setDefault(Authenticator defAuth)
          This method sets the default Authenticator object (an instance of a subclass of Authenticator) to use when prompting the user for information.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Authenticator

public Authenticator()
Default, no-argument constructor for subclasses to call.

Method Detail

setDefault

public static void setDefault(Authenticator defAuth)
This method sets the default Authenticator object (an instance of a subclass of Authenticator) to use when prompting the user for information. Note that this method checks to see if the caller is allowed to set this value (the "setDefaultAuthenticator" permission) and throws a SecurityException if it is not.

Parameters:
defAuth - The new default Authenticator object to use
Throws:
SecurityException - If the caller does not have permission to perform this operation

requestPasswordAuthentication

public static PasswordAuthentication requestPasswordAuthentication(InetAddress addr,
                                                                   int port,
                                                                   String protocol,
                                                                   String prompt,
                                                                   String scheme)
                                                            throws SecurityException
This method is called whenever a username and password for a given network operation is required. First, a security check is made to see if the caller has the "requestPasswordAuthentication" permission. If not, the method thows an exception. If there is no default Authenticator object, the method then returns null. Otherwise, the default authenticators's instance variables are initialized and it's getPasswordAuthentication method is called to get the actual authentication information to return.

Parameters:
addr - The address requesting authentication
port - The port requesting authentication
protocol - The protocol requesting authentication
prompt - The prompt to display to the user when requesting authentication info
scheme - The authentication scheme in use
Returns:
A PasswordAuthentication object with the user's authentication info.
Throws:
SecurityException - If the caller does not have permission to perform this operation

requestPasswordAuthentication

public static PasswordAuthentication requestPasswordAuthentication(String host,
                                                                   InetAddress addr,
                                                                   int port,
                                                                   String protocol,
                                                                   String prompt,
                                                                   String scheme)
                                                            throws SecurityException
This method is called whenever a username and password for a given network operation is required. First, a security check is made to see if the caller has the "requestPasswordAuthentication" permission. If not, the method thows an exception. If there is no default Authenticator object, the method then returns null. Otherwise, the default authenticators's instance variables are initialized and it's getPasswordAuthentication method is called to get the actual authentication information to return. This method is the preferred one as it can be used with hostname when addr is unknown.

Parameters:
host - The hostname requesting authentication
addr - The address requesting authentication
port - The port requesting authentication
protocol - The protocol requesting authentication
prompt - The prompt to display to the user when requesting authentication info
scheme - The authentication scheme in use
Returns:
A PasswordAuthentication object with the user's authentication info.
Throws:
SecurityException - If the caller does not have permission to perform this operation
Since:
1.4

getRequestingSite

protected final InetAddress getRequestingSite()
This method returns the address of the site that is requesting authentication.

Returns:
The requesting site's address

getRequestingHost

protected final String getRequestingHost()
Returns the hostname of the host or proxy requesting authorization, or null if not available.

Returns:
The name of the host requesting authentication, or null if it is not available.
Since:
1.4

getRequestingPort

protected final int getRequestingPort()
This method returns the port of the site that is requesting authentication.

Returns:
The requesting port

getRequestingProtocol

protected final String getRequestingProtocol()
This method returns the requesting protocol of the operation that is requesting authentication

Returns:
The requesting protocol

getRequestingPrompt

protected final String getRequestingPrompt()
Returns the prompt that should be used when requesting authentication information from the user

Returns:
The user prompt

getRequestingScheme

protected final String getRequestingScheme()
This method returns the authentication scheme in use

Returns:
The authentication scheme

getPasswordAuthentication

protected PasswordAuthentication getPasswordAuthentication()
This method is called whenever a request for authentication is made. It can call the other getXXX methods to determine the information relevant to this request. Subclasses should override this method, which returns null by default.

Returns:
The PasswordAuthentication information