libjava/java/security/Provider.java

   1 /* Provider.java -- Security provider information
   2    Copyright (C) 1998, 1999, 2000, 2002 Free Software Foundation, Inc.
   3
   4 This file is 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, or (at your option)
   9 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; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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 package java.security;
  39
  40 import java.io.Serializable;
  41 import java.util.Properties;
  42
  43 /**
  44  * This class represents a Java security architecture service provider.
  45  * The services provided by a such a provider can range from security
  46  * algorithms to key generation.
  47  * <p>
  48  * Providers are installed by name and verion number.  There is one
  49  * standard provider supplied with the class library.  This is the
  50  * "GNU" provider, which can also be accessed by the alias "SUN" for
  51  * compatibility with the JDK.
  52  *
  53  * @version 0.0
  54  *
  55  * @author Aaron M. Renn (arenn@urbanophile.com)
  56  */
  57 public abstract class Provider extends Properties implements Serializable
  58 {
  59   static final long serialVersionUID = -4298000515446427739L;
  60
  61   /**
  62    * This is a textual description of the provider
  63    */
  64   private String info;
  65
  66   /**
  67    * This is the name of the provider
  68    */
  69   private String name;
  70
  71   /**
  72    * This is the version number of the provider
  73    */
  74   private double version;
  75
  76   /**
  77    * This method initializes a new instance of <code>Provider</code> to have
  78    * the specified name, version, and description information.
  79    *
  80    * @param name The name to assign to this <code>Provider</code>.
  81    * @param version The version number for this <code>Provider</code>.
  82    * @param info A textual description of this provider.
  83    */
  84   protected Provider(String name, double version, String info)
  85   {
  86     this.name = name;
  87     this.version = version;
  88     this.info = info;
  89   }
  90
  91   /**
  92    * This method returns the name assigned to this <code>Provider</code>.
  93    *
  94    * @return The <code>Provider</code>'s name.
  95    */
  96   public String getName()
  97   {
  98     return (name);
  99   }
 100
 101   /**
 102    * This method retunrs the version number of this <code>Provider</code>.
 103    *
 104    * @return The <code>Provider</code>'s version number.
 105    */
 106   public double getVersion()
 107   {
 108     return (version);
 109   }
 110
 111   /**
 112    * This method returns a textual description of the <code>Provider</code>.
 113    *
 114    * @return A description of the <code>Provider</code>.
 115    */
 116   public String getInfo()
 117   {
 118     return (info);
 119   }
 120
 121   /**
 122    * Sets the key property to have the specified value.
 123    * <p>
 124    * <bold>NOT IMPLEMENTED YET</bold>[
 125    * First, if there is a security manager, its <code>checkSecurityAccess</code>
 126    * method is called with the string "putProviderProperty."+name, where name is
 127    * the provider name, to see if it's ok to set this provider's property
 128    * values.
 129    * If the default implementation of <code>checkSecurityAccess</code> is used
 130    * (that is, that method is not overriden), then this results in a call to the
 131    * security manager's <code>checkPermission</code> method with a
 132    * <code>SecurityPermission("putProviderProperty."+name)</code>
 133    * permission.<br>]
 134    *
 135    * @param key The property key.
 136    * @param value The property value.
 137    *
 138    * @return The previous value of the specified property (<code>key</code>),
 139    *         or <code>null</code> if it did not have one.
 140    * @throws SecurityException If a security manager exists and its
 141    * {@link java.lang.SecurityManager.checkSecurityAccess(java.lang.String)}
 142    * method denies access to set property values.
 143    * @since Classpath 0.4+cvs, JDK 1.2
 144    * @see java.lang.Object.equals(Object)
 145    * @see java.util.Hashtable.get(Object)
 146    */
 147   public Object put(Object key, Object value)
 148   {
 149     return super.put(toCanonicalKey(key), value);
 150   }
 151
 152   // overrides same in java.util.Hashtable
 153   public Object get(Object key)
 154   {
 155     return super.get(toCanonicalKey(key));
 156   }
 157
 158   /**
 159    * This method removes the specified key entry (and its associated value)
 160    * from the property mapping list.
 161    *
 162    * @param key The key to remove
 163    *
 164    * @return The previous value for this key, or <code>null</code> if no
 165    * previous value.
 166    */
 167   public Object remove(Object key)
 168   {
 169     return super.remove(toCanonicalKey(key));
 170   }
 171
 172   /**
 173    * This method clears the entire property list such that it no longer
 174    * contains the properties used to look up the services provided by
 175    * the <code>Provider</code>.
 176    */
 177   public void clear()
 178   {
 179     super.clear();
 180   }
 181
 182   /**
 183    * This method returns a <code>String</code> representation of this
 184    * object.  This will include the <code>Provider</code> name and
 185    * version number.
 186    *
 187    * @return A <code>String</code> representation of this object.
 188    */
 189   public String toString()
 190   {
 191     return (getClass().getName() + ": name=" + getName() + " version=" +
 192             version);
 193   }
 194
 195   private Object toCanonicalKey(Object key)
 196   {
 197     if (key.getClass().isAssignableFrom(String.class)) // is it ours?
 198       return ((String) key).toUpperCase(); // use default locale
 199     else
 200       return key;
 201   }
 202 }