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    */
search(ORB orb, IOR ior)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    */
createDefaultStub(ORB orb, IOR ior)106   protected static ObjectImpl createDefaultStub(ORB orb, IOR ior)
107   {
108     return new IorObject(orb, ior);
109   }
110 }
111