libjava/classpath/gnu/javax/naming/giop/GiopNamingServiceFactory.java

   1 /* GiopNamingServiceFactory.java -- handles corbaname: urls
   2    Copyright (C) 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 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.naming.giop;
  40
  41 import gnu.CORBA.OrbFunctional;
  42
  43 import gnu.java.lang.CPStringBuilder;
  44
  45 import java.util.Enumeration;
  46 import java.util.Hashtable;
  47 import java.util.Iterator;
  48 import java.util.Map;
  49 import java.util.Properties;
  50 import java.util.TreeMap;
  51
  52 import javax.naming.Context;
  53 import javax.naming.Name;
  54
  55 import org.omg.CORBA.ORB;
  56
  57 /**
  58  * The context factory to represent the corbaname: style urls. Such URL states
  59  * that the CORBA naming service exists on the given host. This service can
  60  * return the required object, finding it by the given name. The names are
  61  * parsed using the specification of the corbaname urls. Being the naming
  62  * service, the returned context supports creating the subcontexts, forwarding
  63  * this task to the existing naming service.
  64  *
  65  * @author Audrius Meskauskas (audriusa@Bioinformatics.org)
  66  */
  67 public class GiopNamingServiceFactory
  68 {
  69   /**
  70    * The default naming service provider. It is assumed, that the naming service
  71    * is running on the port 900 of the local host, using the GIOP version 1.2
  72    */
  73   public static final String DEFAULT_PROVIDER =
  74     "corbaloc:iiop:1.2@127.0.0.1:900/NameService";
  75
  76   /**
  77    * The table of all instantiated ORB's that are found by they ORB
  78    * properties signatures. If all ORB related properties are the same,
  79    * the ORB's are shared.
  80    */
  81   public static Hashtable orbs = new Hashtable();
  82
  83
  84   /**
  85    * Create a new instance of the corbaname URL context.
  86    */
  87   public Object getObjectInstance(Object refObj, Name name, Context nameCtx,
  88                                   Hashtable environment)
  89   {
  90     String provider = (String) environment.get(Context.PROVIDER_URL);
  91     if (provider == null)
  92       provider = DEFAULT_PROVIDER;
  93
  94     String orbSignature = getOrbSignature(environment);
  95
  96     ORB orb;
  97     synchronized (orbs)
  98       {
  99         orb = (ORB) orbs.get(orbSignature);
 100         if (orb == null)
 101           {
 102             Properties props = new Properties();
 103             props.putAll(environment);
 104             orb = ORB.init(new String[0], props);
 105             orbs.put(orbSignature, orb);
 106             final ORB runIt = orb;
 107             new Thread()
 108             {
 109               public void run()
 110               {
 111                 runIt.run();
 112               }
 113             }.start();
 114           }
 115       }
 116
 117     return new GiopNamingServiceURLContext(environment, this, orb);
 118   }
 119
 120   /**
 121    * Check if this ORB is still in use (maybe it is time to shutdown it). This
 122    * method only works when the Classpath CORBA implementation is used
 123    * (otherwise it return without action). The method is called from the close()
 124    * method of the created context.
 125    *
 126    * @param orb
 127    *          the ORB that maybe is no longer referenced.
 128    */
 129   public void checkIfReferenced(ORB orb)
 130   {
 131     synchronized (orbs)
 132       {
 133         // We can only do this with the Classpath implementation.
 134         if (orb instanceof OrbFunctional)
 135           {
 136             OrbFunctional cOrb = (OrbFunctional) orb;
 137             // If there are no connected objects, we can destroy the orb.
 138             if (cOrb.countConnectedObjects() == 0)
 139               {
 140                 cOrb.shutdown(false);
 141                 cOrb.destroy();
 142
 143                 Enumeration keys = orbs.keys();
 144                 Object key;
 145                 Remove: while (keys.hasMoreElements())
 146                   {
 147                     key = keys.nextElement();
 148                     if (orbs.get(key) == orb)
 149                       {
 150                         orbs.remove(key);
 151                         break Remove;
 152                       }
 153                   }
 154               }
 155           }
 156       }
 157   }
 158
 159   /**
 160    * Get all properties.
 161    */
 162   public String getOrbSignature(Map props)
 163   {
 164      TreeMap map = new TreeMap();
 165      map.putAll(props);
 166      CPStringBuilder b = new CPStringBuilder(50*props.size());
 167
 168      Iterator iter = map.entrySet().iterator();
 169      Map.Entry m;
 170      while (iter.hasNext())
 171        {
 172          m = (Map.Entry) iter.next();
 173          b.append(m.getKey());
 174          b.append('=');
 175          b.append(m.getValue());
 176        }
 177      return b.toString();
 178   }
 179 }