Source for gnu.javax.naming.giop.GiopNamingServiceFactory

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