001    /* SocketFactory.java -- factory for client sockets.
002       Copyright (C) 2004 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    
039    package javax.net;
040    
041    import java.io.IOException;
042    
043    import java.net.InetAddress;
044    import java.net.Socket;
045    import java.net.UnknownHostException;
046    
047    import java.security.Security;
048    
049    /**
050     * A factory for client sockets. The purpose of this class is to serve
051     * as the superclass of server socket factories that produce client
052     * sockets of a particular type, such as <i>Secure Socket Layer</i>
053     * (<b>SSL</b>) sockets.
054     *
055     * @author Casey Marshall (rsdio@metastatic.org)
056     */
057    public abstract class SocketFactory
058    {
059    
060      // Constructor.
061      // -------------------------------------------------------------------
062    
063      /**
064       * Default 0-arguments constructor.
065       */
066      protected SocketFactory()
067      {
068        super();
069      }
070    
071      // Class methods.
072      // -------------------------------------------------------------------
073    
074      /**
075       * Returns the default socket factory. The type of factory
076       * returned may depend upon the installation.
077       *
078       * @return The default socket factory.
079       */
080      public static synchronized SocketFactory getDefault()
081      {
082        try
083          {
084            String s = Security.getProperty("gnu.defaultSocketFactory");
085            if (s != null)
086              {
087                Class c = Class.forName(s);
088                return (SocketFactory) c.newInstance();
089              }
090          }
091        catch (Exception e)
092          {
093          }
094        return new VanillaSocketFactory();
095      }
096    
097      // Instance methods.
098      // -------------------------------------------------------------------
099    
100      /**
101       * Returns an unbound client socket.
102       *
103       * @return The new, unbound socket.
104       */
105      public Socket createSocket() throws IOException
106      {
107        throw new UnsupportedOperationException();
108      }
109    
110      /**
111       * Creates a socket connected to a given host on a given port.
112       *
113       * @param host The hostname to connect to.
114       * @param port The port on <i>host</i> to connect to.
115       * @return A socket connected to <i>host</i> on <i>port</i>.
116       * @throws IOException If a network error occurs.
117       * @throws UnknownHostException If <i>host</i> cannot be resolved.
118       */
119      public abstract Socket createSocket(String host, int port) throws IOException, UnknownHostException;
120    
121      /**
122       * Creates a socket connected to a given host on a given port,
123       * connecting locally to the interface with the given address and port.
124       *
125       * @param host The hostname to connect to.
126       * @param port The port on <i>host</i> to connect to.
127       * @param localHost The address of the local interface to bind to.
128       * @param localPort The local port to bind to.
129       * @return A socket connected to <i>host</i> on <i>port</i>.
130       * @throws IOException If a network error occurs.
131       * @throws UnknownHostException If <i>host</i> cannot be resolved.
132       */
133      public abstract Socket createSocket(String host, int port, InetAddress localHost, int localPort) throws IOException, UnknownHostException;
134    
135      /**
136       * Creates a socket connected to a given host on a given port.
137       *
138       * @param host The host address to connect to.
139       * @param port The port on <i>host</i> to connect to.
140       * @return A socket connected to <i>host</i> on <i>port</i>.
141       * @throws IOException If a network error occurs.
142       */
143      public abstract Socket createSocket(InetAddress host, int port) throws IOException;
144    
145      /**
146       * Creates a socket connected to a given host on a given port,
147       * connecting locally to the interface with the given address and port.
148       *
149       * @param host The host address  to connect to.
150       * @param port The port on <i>host</i> to connect to.
151       * @param localHost The address of the local interface to bind to.
152       * @param localPort The local port to bind to.
153       * @return A socket connected to <i>host</i> on <i>port</i>.
154       * @throws IOException If a network error occurs.
155       */
156      public abstract Socket createSocket(InetAddress hast, int port, InetAddress localHost, int localPort) throws IOException;
157    }