Java in a Nutshell, 5th Edition

Name

Package javax.security.auth.login

Synopsis

This package defines the LoginContext class which is one of the primary JAAS classes used by application programmers. To authenticate a user, an application creates a LoginContext object, specifying the application name (used to lookup the type of authentication required for that application in the Configuration) and usually specifying a javax.security.auth.callback.CallbackHandler for communication between the user and the underlying login modules. Next, the application calls the login( ) method of the LoginContext to perform the actual login. If this method returns without throwing a LoginException, then the user was sucessfully authenticated, and the getSubject( ) method of LoginContext returns a javax.security.auth.Subject representing the user. The code might look like this:

import javax.security.auth.*; import javax.security.auth.callback.*; import javax.security.auth.login.*; // Get a default GUI-based CallbackHandler CallbackHandler h = new com.sun.security.auth.callback.DialogCallbackHandler( ); // Try to create a LoginContext for use with this application LoginContext context; try { context = new LoginContext("MyAppName", h); } catch(LoginException e) { System.err.println("LoginContext configuration error: " + e.getMessage( )); System.exit(-1); } // Now use that context to authenticate the user try { context.login( ); } catch(LoginException e) { System.err.println("Authentication failed: " + e.getMessage( )); System.exit(-1); ...