001    /* ProxySelector.java -- A proxy selector class
002       Copyright (C) 2006  Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package java.net;
039    
040    import gnu.java.net.DefaultProxySelector;
041    
042    import java.io.IOException;
043    import java.util.List;
044    
045    /**
046     * Class for handling proxies for different connections.
047     * 
048     * @since 1.5
049     */
050    public abstract class ProxySelector
051    {
052      /**
053       * Default proxy selector.
054       */
055      private static ProxySelector defaultSelector = new DefaultProxySelector();
056    
057      /**
058       * Creates a new <code>ProxySelector</code> object.
059       */
060      public ProxySelector()
061      {
062        // Do nothing here.
063      }
064    
065      /**
066       * Returns the default proxy selector.
067       *
068       * @return the default proxy selector
069       *
070       * @throws SecurityException If a security manager is installed and it
071       * denies NetPermission("getProxySelector")
072       */
073      public static ProxySelector getDefault()
074      {
075        SecurityManager sm = System.getSecurityManager();
076    
077        if (sm != null)
078          sm.checkPermission(new NetPermission("getProxySelector"));
079    
080        return defaultSelector;
081      }
082    
083      /**
084       * Sets the default proxy selector.
085       *
086       * @param selector the defualt proxy selector
087       *
088       * @throws SecurityException If a security manager is installed and it
089       * denies NetPermission("setProxySelector")
090       */
091      public static void setDefault(ProxySelector selector)
092      {
093        SecurityManager sm = System.getSecurityManager();
094    
095        if (sm != null)
096          sm.checkPermission(new NetPermission("setProxySelector"));
097    
098        defaultSelector = selector;
099      }
100    
101      /**
102       * Signals to the selector that a proxy was no available.
103       * 
104       * @throws IllegalArgumentException If one argument is null
105       */
106      public abstract void connectFailed(URI uri, SocketAddress address,
107                                         IOException exception);
108    
109      /**
110       * Returns the list of proxy settings for a given URI.
111       *
112       * @return list of proxy settings
113       * 
114       * @throws IllegalArgumentException If uri is null
115       */
116      public abstract List<Proxy> select(URI uri);
117    }