Source for gnu.CORBA.StubLocator

   1: /* StubLocator.java --
   2:    Copyright (C) 2005 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.CORBA;
  40: 
  41: import org.omg.CORBA.ORB;
  42: import org.omg.CORBA.portable.ObjectImpl;
  43: 
  44: /**
  45:  * Finds a stub class like "_HelloStub" that can be instantiated
  46:  * from IOR reference. The returned object can be casted to the
  47:  * used type like "Hello" without using the helper .narrow method,
  48:  * and the object is not unnsecessarily re - instantiated if
  49:  * the .narrow method is used anyway. If no stub, matching the naming
  50:  * conventions, is available, the returned stub replacement can still be used
  51:  * to get the valid request, add parameter and invoke the method by name.
  52:  *
  53:  * @author Audrius Meskauskas (AudriusA@Bioinformatics.org)
  54:  */
  55: public class StubLocator
  56: {
  57:   /**
  58:    * Search for the possibly available default stub.
  59:    *
  60:    * @param orb the current ORB. It is not required to find the binding
  61:    * classes, but is needed to instantiate the default implementation
  62:    * if no binding classes are found.
  63:    *
  64:    * @param ior the IOR, possibly containing the information about the
  65:    * correct implementation class.
  66:    */
  67:   public static ObjectImpl search(ORB orb, IOR ior)
  68:   {
  69:     try
  70:       {
  71:         int a = ior.Id.indexOf(':');
  72:         int b = ior.Id.lastIndexOf(':');
  73: 
  74:         String s = ior.Id.substring(a + 1, b).replace('/', '.');
  75: 
  76:         String path;
  77: 
  78:         b = s.lastIndexOf('.');
  79:         if (b > 0)
  80:           path = s.substring(0, b + 1);
  81:         else
  82:           path = "";
  83: 
  84:         String stub = "_" + s.substring(b + 1) + "Stub";
  85: 
  86:         Class stubClass = ObjectCreator.forName(path + stub);
  87: 
  88:         return (ObjectImpl) stubClass.newInstance();
  89:       }
  90:     catch (Exception failed)
  91:       {
  92:         // Various exceptions can be thrown if the Id cannot be parsed,
  93:         // the class is missing, cannot be instantiated or is not an
  94:         // instance of the ObjectImpl.
  95:         return createDefaultStub(orb, ior);
  96:       }
  97:   }
  98: 
  99:   /**
 100:    * Return the default stub for the case when the client binding classes
 101:    * are not locally available. The returned stub can still be used
 102:    * to get the valid request, add parameter and invoke the method by name.
 103:    *
 104:    * @return the default implementation.
 105:    */
 106:   protected static ObjectImpl createDefaultStub(ORB orb, IOR ior)
 107:   {
 108:     return new IorObject(orb, ior);
 109:   }
 110: }