libjava/classpath/gnu/javax/security/auth/callback/AbstractCallbackHandler.java

   1 /* AbstractCallbackHandler.java --
   2    Copyright (C) 2005, 2006  Free Software Foundation, Inc.
   3
   4 This file is a part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or (at
   9 your option) any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; if not, write to the Free Software
  18 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
  19 USA
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version.  */
  37
  38
  39 package gnu.javax.security.auth.callback;
  40
  41 import gnu.java.security.Engine;
  42
  43 import java.io.IOException;
  44 import java.lang.reflect.InvocationTargetException;
  45 import java.util.PropertyResourceBundle;
  46 import java.util.ResourceBundle;
  47
  48 import java.security.NoSuchAlgorithmException;
  49 import java.security.NoSuchProviderException;
  50 import java.security.Provider;
  51 import java.security.Security;
  52
  53 import javax.security.auth.callback.Callback;
  54 import javax.security.auth.callback.CallbackHandler;
  55 import javax.security.auth.callback.ChoiceCallback;
  56 import javax.security.auth.callback.ConfirmationCallback;
  57 import javax.security.auth.callback.LanguageCallback;
  58 import javax.security.auth.callback.NameCallback;
  59 import javax.security.auth.callback.PasswordCallback;
  60 import javax.security.auth.callback.TextInputCallback;
  61 import javax.security.auth.callback.TextOutputCallback;
  62 import javax.security.auth.callback.UnsupportedCallbackException;
  63
  64 public abstract class AbstractCallbackHandler implements CallbackHandler
  65 {
  66
  67   // Fields.
  68   // -------------------------------------------------------------------------
  69
  70   private static final String SERVICE = "CallbackHandler";
  71
  72   protected final ResourceBundle messages;
  73
  74   private final String name;
  75
  76   // Constructors.
  77   // -------------------------------------------------------------------------
  78
  79   protected AbstractCallbackHandler (final String name)
  80   {
  81     super();
  82     messages = PropertyResourceBundle.getBundle("gnu/javax/security/auth/callback/MessagesBundle");
  83     this.name = name;
  84   }
  85
  86   // Class methods.
  87   // -------------------------------------------------------------------------
  88
  89   public static CallbackHandler getInstance(String type)
  90     throws NoSuchAlgorithmException
  91   {
  92     Provider[] p = Security.getProviders();
  93     for (int i = 0; i < p.length; i++)
  94       {
  95         try
  96           {
  97             return getInstance(type, p[i]);
  98           }
  99         catch (NoSuchAlgorithmException ignored)
 100           {
 101           }
 102       }
 103     throw new NoSuchAlgorithmException(type);
 104   }
 105
 106   public static CallbackHandler getInstance(String type, String provider)
 107     throws NoSuchAlgorithmException, NoSuchProviderException
 108   {
 109     Provider p = Security.getProvider(provider);
 110     if (p == null)
 111       {
 112         throw new NoSuchProviderException(provider);
 113       }
 114     return getInstance(type, p);
 115   }
 116
 117   public static CallbackHandler getInstance(String type, Provider provider)
 118     throws NoSuchAlgorithmException
 119   {
 120     try
 121       {
 122         return (CallbackHandler) Engine.getInstance(SERVICE, type, provider);
 123       }
 124     catch (InvocationTargetException ite)
 125       {
 126         Throwable cause = ite.getCause();
 127         if (cause instanceof NoSuchAlgorithmException)
 128           throw (NoSuchAlgorithmException) cause;
 129         NoSuchAlgorithmException nsae = new NoSuchAlgorithmException(type);
 130         if (cause != null)
 131           nsae.initCause (cause);
 132         throw nsae;
 133       }
 134     catch (ClassCastException cce)
 135       {
 136         NoSuchAlgorithmException nsae = new NoSuchAlgorithmException(type);
 137         nsae.initCause (cce);
 138         throw nsae;
 139       }
 140   }
 141
 142   // Instance methods.
 143   // -------------------------------------------------------------------------
 144
 145   public void handle(Callback[] callbacks)
 146     throws IOException, UnsupportedCallbackException
 147   {
 148     if (callbacks == null)
 149       throw new NullPointerException();
 150     for (int i = 0; i < callbacks.length; i++)
 151       {
 152         if (callbacks[i] == null)
 153           continue;
 154         if (callbacks[i] instanceof ChoiceCallback)
 155           handleChoice((ChoiceCallback) callbacks[i]);
 156         else if (callbacks[i] instanceof ConfirmationCallback)
 157           handleConfirmation((ConfirmationCallback) callbacks[i]);
 158         else if (callbacks[i] instanceof LanguageCallback)
 159           handleLanguage((LanguageCallback) callbacks[i]);
 160         else if (callbacks[i] instanceof NameCallback)
 161           handleName((NameCallback) callbacks[i]);
 162         else if (callbacks[i] instanceof PasswordCallback)
 163           handlePassword((PasswordCallback) callbacks[i]);
 164         else if (callbacks[i] instanceof TextInputCallback)
 165           handleTextInput((TextInputCallback) callbacks[i]);
 166         else if (callbacks[i] instanceof TextOutputCallback)
 167           handleTextOutput((TextOutputCallback) callbacks[i]);
 168         else
 169           handleOther(callbacks[i]);
 170       }
 171   }
 172
 173   public final String getName ()
 174   {
 175     return name;
 176   }
 177
 178   // Abstract methods.
 179   // -------------------------------------------------------------------------
 180
 181   /**
 182    * Handles a {@link ChoiceCallback}.
 183    *
 184    * @param callback The choice callback.
 185    * @throws IOException If an I/O error occurs.
 186    */
 187   protected abstract void handleChoice(ChoiceCallback callback)
 188     throws IOException;
 189
 190   /**
 191    * Handles a {@link ConfirmationCallback}.
 192    *
 193    * @param callback The confirmation callback.
 194    * @throws IOException If an I/O error occurs.
 195    */
 196   protected abstract void handleConfirmation(ConfirmationCallback callback)
 197     throws IOException;
 198
 199   /**
 200    * Handles a {@link LanguageCallback}.
 201    *
 202    * @param callback The language callback.
 203    * @throws IOException If an I/O error occurs.
 204    */
 205   protected abstract void handleLanguage(LanguageCallback callback)
 206     throws IOException;
 207
 208   /**
 209    * Handles a {@link NameCallback}.
 210    *
 211    * @param callback The name callback.
 212    * @throws IOException If an I/O error occurs.
 213    */
 214   protected abstract void handleName(NameCallback callback)
 215     throws IOException;
 216
 217   /**
 218    * Handles a {@link PasswordCallback}.
 219    *
 220    * @param callback The password callback.
 221    * @throws IOException If an I/O error occurs.
 222    */
 223   protected abstract void handlePassword(PasswordCallback callback)
 224     throws IOException;
 225
 226   /**
 227    * Handles a {@link TextInputCallback}.
 228    *
 229    * @param callback The text input callback.
 230    * @throws IOException If an I/O error occurs.
 231    */
 232   protected abstract void handleTextInput(TextInputCallback callback)
 233     throws IOException;
 234
 235   /**
 236    * Handles a {@link TextOutputCallback}.
 237    *
 238    * @param callback The text output callback.
 239    * @throws IOException If an I/O error occurs.
 240    */
 241   protected abstract void handleTextOutput(TextOutputCallback callback)
 242     throws IOException;
 243
 244   /**
 245    * Handles an unknown callback. The default implementation simply throws
 246    * an {@link UnsupportedCallbackException}.
 247    *
 248    * @param callback The callback to handle.
 249    * @throws IOException If an I/O error occurs.
 250    * @throws UnsupportedCallbackException If the specified callback is not
 251    *   supported.
 252    */
 253   protected void handleOther(Callback callback)
 254     throws IOException, UnsupportedCallbackException
 255   {
 256     throw new UnsupportedCallbackException(callback);
 257   }
 258 }