Module java.base
Package java.net

Class Authenticator

java.lang.Object
java.net.Authenticator
public abstract class Authenticator extends Object
The class Authenticator represents an object that knows how to obtain authentication for a network connection. Usually, it will do this by prompting the user for information.

Applications use this class by overriding getPasswordAuthentication() in a sub-class. This method will typically use the various getXXX() accessor methods to get information about the entity requesting authentication. It must then acquire a username and password either by interacting with the user or through some other non-interactive means. The credentials are then returned as a PasswordAuthentication return value.

An instance of this concrete sub-class is then registered with the system by calling setDefault(Authenticator). When authentication is required, the system will invoke one of the requestPasswordAuthentication() methods which in turn will call the getPasswordAuthentication() method of the registered object.

All methods that request authentication have a default implementation that fails.

Since:
1.2
See Also:

  • Constructor Details

    • Authenticator

      public Authenticator()
      Constructor for subclasses to call.

  • Method Details

    • setDefault

      public static void setDefault(Authenticator a)
      Sets the authenticator that will be used by the networking code when a proxy or an HTTP server asks for authentication.

      First, if there is a security manager, its checkPermission method is called with a NetPermission("setDefaultAuthenticator") permission. This may result in a java.lang.SecurityException.

      Parameters:
      a - The authenticator to be set. If a is null then any previously set authenticator is removed.
      Throws:
      SecurityException - if a security manager exists and its checkPermission method doesn't allow setting the default authenticator.
      See Also:

    • getDefault

      public static Authenticator getDefault()
      Gets the default authenticator. First, if there is a security manager, its checkPermission method is called with a NetPermission("requestPasswordAuthentication") permission. This may result in a java.lang.SecurityException. Then the default authenticator, if set, is returned. Otherwise, null is returned.
      Returns:
      The default authenticator, if set, null otherwise.
      Throws:
      SecurityException - if a security manager exists and its checkPermission method doesn't allow requesting password authentication.
      Since:
      9
      See Also:

    • requestPasswordAuthentication

      public static PasswordAuthentication requestPasswordAuthentication(InetAddress addr, int port, String protocol, String prompt, String scheme)
      Ask the authenticator that has been registered with the system for a password.

      First, if there is a security manager, its checkPermission method is called with a NetPermission("requestPasswordAuthentication") permission. This may result in a java.lang.SecurityException.

      Parameters:
      addr - The InetAddress of the site requesting authorization, or null if not known.
      port - the port for the requested connection
      protocol - The protocol that's requesting the connection (getRequestingProtocol())
      prompt - A prompt string for the user
      scheme - The authentication scheme
      Returns:
      The username/password, or null if one can't be gotten.
      Throws:
      SecurityException - if a security manager exists and its checkPermission method doesn't allow the password authentication request.
      See Also:

    • requestPasswordAuthentication

      public static PasswordAuthentication requestPasswordAuthentication(String host, InetAddress addr, int port, String protocol, String prompt, String scheme)
      Ask the authenticator that has been registered with the system for a password. This is the preferred method for requesting a password because the hostname can be provided in cases where the InetAddress is not available.

      First, if there is a security manager, its checkPermission method is called with a NetPermission("requestPasswordAuthentication") permission. This may result in a java.lang.SecurityException.

      Parameters:
      host - The hostname of the site requesting authentication.
      addr - The InetAddress of the site requesting authentication, or null if not known.
      port - the port for the requested connection.
      protocol - The protocol that's requesting the connection (getRequestingProtocol())
      prompt - A prompt string for the user which identifies the authentication realm.
      scheme - The authentication scheme
      Returns:
      The username/password, or null if one can't be gotten.
      Throws:
      SecurityException - if a security manager exists and its checkPermission method doesn't allow the password authentication request.
      Since:
      1.4
      See Also:

    • requestPasswordAuthentication

      public static PasswordAuthentication requestPasswordAuthentication(String host, InetAddress addr, int port, String protocol, String prompt, String scheme, URL url, Authenticator.RequestorType reqType)
      Ask the authenticator that has been registered with the system for a password.

      First, if there is a security manager, its checkPermission method is called with a NetPermission("requestPasswordAuthentication") permission. This may result in a java.lang.SecurityException.

      Parameters:
      host - The hostname of the site requesting authentication.
      addr - The InetAddress of the site requesting authorization, or null if not known.
      port - the port for the requested connection
      protocol - The protocol that's requesting the connection (getRequestingProtocol())
      prompt - A prompt string for the user
      scheme - The authentication scheme
      url - The requesting URL that caused the authentication
      reqType - The type (server or proxy) of the entity requesting authentication.
      Returns:
      The username/password, or null if one can't be gotten.
      Throws:
      SecurityException - if a security manager exists and its checkPermission method doesn't allow the password authentication request.
      Since:
      1.5
      See Also:

    • requestPasswordAuthentication

      public static PasswordAuthentication requestPasswordAuthentication(Authenticator authenticator, String host, InetAddress addr, int port, String protocol, String prompt, String scheme, URL url, Authenticator.RequestorType reqType)
      Ask the given authenticator for a password. If the given authenticator is null, the authenticator, if any, that has been registered with the system using setDefault is used.

      First, if there is a security manager, its checkPermission method is called with a NetPermission("requestPasswordAuthentication") permission. This may result in a java.lang.SecurityException.

      Parameters:
      authenticator - the authenticator, or null.
      host - The hostname of the site requesting authentication.
      addr - The InetAddress of the site requesting authorization, or null if not known.
      port - the port for the requested connection
      protocol - The protocol that's requesting the connection (getRequestingProtocol())
      prompt - A prompt string for the user
      scheme - The authentication scheme
      url - The requesting URL that caused the authentication
      reqType - The type (server or proxy) of the entity requesting authentication.
      Returns:
      The username/password, or null if one can't be gotten.
      Throws:
      SecurityException - if a security manager exists and its checkPermission method doesn't allow the password authentication request.
      Since:
      9
      See Also:

    • requestPasswordAuthenticationInstance

      public PasswordAuthentication requestPasswordAuthenticationInstance(String host, InetAddress addr, int port, String protocol, String prompt, String scheme, URL url, Authenticator.RequestorType reqType)
      Ask this authenticator for a password.
      Parameters:
      host - The hostname of the site requesting authentication.
      addr - The InetAddress of the site requesting authorization, or null if not known.
      port - the port for the requested connection
      protocol - The protocol that's requesting the connection (getRequestingProtocol())
      prompt - A prompt string for the user
      scheme - The authentication scheme
      url - The requesting URL that caused the authentication
      reqType - The type (server or proxy) of the entity requesting authentication.
      Returns:
      The username/password, or null if one can't be gotten
      Since:
      9

    • getRequestingHost

      protected final String getRequestingHost()
      Gets the hostname of the site or proxy requesting authentication, or null if not available.
      Returns:
      the hostname of the connection requiring authentication, or null if it's not available.
      Since:
      1.4

    • getRequestingSite

      protected final InetAddress getRequestingSite()
      Gets the InetAddress of the site requesting authorization, or null if not available.
      Returns:
      the InetAddress of the site requesting authorization, or null if it's not available.

    • getRequestingPort

      protected final int getRequestingPort()
      Gets the port number for the requested connection.
      Returns:
      an int indicating the port for the requested connection.

    • getRequestingProtocol

      protected final String getRequestingProtocol()
      Give the protocol that's requesting the connection. Often this will be based on a URL, but in a future JDK it could be, for example, "SOCKS" for a password-protected SOCKS5 firewall.
      Returns:
      the protocol, optionally followed by "/version", where version is a version number.
      See Also:

    • getRequestingPrompt

      protected final String getRequestingPrompt()
      Gets the prompt string given by the requestor.
      Returns:
      the prompt string given by the requestor (realm for http requests)

    • getRequestingScheme

      protected final String getRequestingScheme()
      Gets the scheme of the requestor (the HTTP scheme for an HTTP firewall, for example).
      Returns:
      the scheme of the requestor

    • getPasswordAuthentication

      protected PasswordAuthentication getPasswordAuthentication()
      Called when password authorization is needed. Subclasses should override the default implementation, which returns null.
      Returns:
      The PasswordAuthentication collected from the user, or null if none is provided.

    • getRequestingURL

      protected URL getRequestingURL()
      Returns the URL that resulted in this request for authentication.
      Returns:
      the requesting URL
      Since:
      1.5

    • getRequestorType

      protected Authenticator.RequestorType getRequestorType()
      Returns whether the requestor is a Proxy or a Server.
      Returns:
      the authentication type of the requestor
      Since:
      1.5