java.net
Class Authenticator
java.lang.Object
|
+--java.net.Authenticator
public abstract class
Authenticatorextends
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 of
Authenticator 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:Author:- Aaron M. Renn (arenn@urbanophile.com)
Authenticator
public Authenticator()
Default, no-argument constructor for subclasses to call.
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
getRequestingHost
protected final String getRequestingHost()
Returns the hostname of the host or proxy requesting authorization,
or null if not available.
Since:
getRequestingPort
protected final int getRequestingPort()
This method returns the port of the site that is requesting
authentication.
Returns:
getRequestingPrompt
protected final String getRequestingPrompt()
Returns the prompt that should be used when requesting authentication
information from the user
Returns:
getRequestingProtocol
protected final String getRequestingProtocol()
This method returns the requesting protocol of the operation that is
requesting authentication
Returns:
getRequestingScheme
protected final String getRequestingScheme()
This method returns the authentication scheme in use
Returns:
- The authentication scheme
getRequestingSite
protected final InetAddress getRequestingSite()
This method returns the address of the site that is requesting
authentication.
Returns:
requestPasswordAuthentication
public static PasswordAuthentication requestPasswordAuthentication(java.lang.String host, java.net.InetAddress addr, int port, java.lang.String protocol, java.lang.String prompt, java.lang.String scheme)
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.
Since:Parameters:
Returns:
- A
PasswordAuthentication
object with the user's
authentication info.
Throws:
requestPasswordAuthentication
public static PasswordAuthentication requestPasswordAuthentication(java.net.InetAddress addr, int port, java.lang.String protocol, java.lang.String prompt, java.lang.String scheme)
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:
Returns:
- A
PasswordAuthentication
object with the user's
authentication info.
Throws:
setDefault
public static void setDefault(java.net.Authenticator def_auth)
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:
Throws:
To make use of this feature, a programmer must create a subclass of Authenticator 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.