/* Configuration.java   Copyright (C) 2004 Free Software Foundation, Inc.This file is part of GNU Classpath.GNU Classpath is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2, or (at your option)any later version.GNU Classpath is distributed in the hope that it will be useful, butWITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNUGeneral Public License for more details.You should have received a copy of the GNU General Public Licensealong with GNU Classpath; see the file COPYING.  If not, write to theFree Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA02110-1301 USA.Linking this library statically or dynamically with other modules ismaking a combined work based on this library.  Thus, the terms andconditions of the GNU General Public License cover the wholecombination.As a special exception, the copyright holders of this library give youpermission to link this library with independent modules to produce anexecutable, regardless of the license terms of these independentmodules, and to copy and distribute the resulting executable underterms of your choice, provided that you also meet, for each linkedindependent module, the terms and conditions of the license of thatmodule.  An independent module is a module which is not derived fromor based on this library.  If you modify this library, you may extendthis exception to your version of the library, but you are notobligated to do so.  If you do not wish to do so, delete thisexception statement from your version. */package javax.security.auth.login;import java.security.AccessController;import java.security.PrivilegedAction;import java.security.Security;import javax.security.auth.AuthPermission;public abstract class Configuration{  // Fields.  // -------------------------------------------------------------------------  private static Configuration config;  // Constructors.  // -------------------------------------------------------------------------  protected Configuration()  {  }  // Class methods.  // -------------------------------------------------------------------------  public static synchronized Configuration getConfiguration()  {    SecurityManager sm = System.getSecurityManager();    if (sm != null)      sm.checkPermission (new AuthPermission ("getLoginConfiguration"));    return getConfig();  }  public static synchronized void setConfiguration (Configuration config)  {    SecurityManager sm = System.getSecurityManager();    if (sm != null)      sm.checkPermission (new AuthPermission ("setLoginConfiguration"));    Configuration.config = config;  }  // Abstract methods.  // -------------------------------------------------------------------------  public abstract AppConfigurationEntry[] getAppConfigurationEntry (String applicationName);  public abstract void refresh();  // Package-private methods.  // -------------------------------------------------------------------------  /**   * Get the current configuration, bypassing security checks.   */  static Configuration getConfig()  {    if (config == null)      {        String conf = (String) AccessController.doPrivileged          (new PrivilegedAction()            {              public Object run()              {                return Security.getProperty ("login.configuration.provider");              }            });        try          {            if (conf != null)              config = (Configuration) Class.forName (conf).newInstance();            else              config = new NullConfiguration();          }        catch (Exception x)          {            config = new NullConfiguration();          }      }    return config;  }}