001/* ControlFactory.java --
002   Copyright (C) 2001, 2004  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package javax.naming.ldap;
040
041import java.util.Hashtable;
042import java.util.StringTokenizer;
043
044import javax.naming.Context;
045import javax.naming.NamingException;
046
047/**
048 * @author Tom Tromey (tromey@redhat.com)
049 * @date June 22, 2001
050 */
051public abstract class ControlFactory
052{
053  protected ControlFactory ()
054  {
055  }
056
057  public abstract Control getControlInstance (Control control)
058    throws NamingException;
059
060  public static Control getControlInstance (Control control,
061                                            Context ctx,
062                                            Hashtable<?, ?> env)
063    throws NamingException
064  {
065    String path = (String) env.get (LdapContext.CONTROL_FACTORIES);
066    String path2 = null;
067    if (ctx != null)
068      path2 = (String) ctx.getEnvironment ().get (LdapContext.CONTROL_FACTORIES);
069    if (path == null)
070      path = path2;
071    else if (path2 != null)
072      path += ":" + path2;
073
074    StringTokenizer tokens = new StringTokenizer (path, ":");
075    while (tokens.hasMoreTokens ())
076      {
077        String name = tokens.nextToken ();
078        try
079          {
080            Class k = Class.forName (name);
081            ControlFactory cf = (ControlFactory) k.newInstance ();
082            Control ctrl = cf.getControlInstance (control);
083            if (ctrl != null)
084              return ctrl;
085          }
086        catch (ClassNotFoundException _1)
087          {
088            // Ignore it.
089          }
090        catch (ClassCastException _2)
091          {
092            // Ignore it.
093          }
094        catch (InstantiationException _3)
095          {
096            // If we couldn't instantiate the factory we might get
097            // this.
098          }
099        catch (IllegalAccessException _4)
100          {
101            // Another possibility when instantiating.
102          }
103      }
104
105    return control;
106  }
107}