RepositoryID


1   package org.jacorb.ir;
2   
3   /*
4    *        JacORB - a free Java ORB
5    *
6    *   Copyright (C) 1997-2004 Gerald Brose.
7    *
8    *   This library is free software; you can redistribute it and/or
9    *   modify it under the terms of the GNU Library General Public
10   *   License as published by the Free Software Foundation; either
11   *   version 2 of the License, or (at your option) any later version.
12   *
13   *   This library is distributed in the hope that it will be useful,
14   *   but WITHOUT ANY WARRANTY; without even the implied warranty of
15   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16   *   Library General Public License for more details.
17   *
18   *   You should have received a copy of the GNU Library General Public
19   *   License along with this library; if not, write to the Free
20   *   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21   */
22  
23  import java.util.StringTokenizer  ;
24  import org.omg.CORBA.portable.BoxedValueHelper  ;
25  import org.omg.CORBA.INTF_REPOS  ;
26  
27  /**
28   * This class builds CORBA repository IDs from Java classes
29   * or class names, or builds Java class names from repository
30   * IDs
31   */
32  public class RepositoryID
33  {
34      /**
35       * Returns the fully qualified name of the Java class to which
36       * the given Repository ID is mapped.
37       */
38      public static String   className (String   repId, 
39                                      ClassLoader   loader)
40      {
41          return className (repId, null, loader);
42      }
43  
44      /**
45       * Returns the fully qualified name of the Java class to which
46       * the given Repository ID is mapped, with a given suffix appended
47       * to the class name.  For example, the string "Helper" can be used
48       * as the suffix to find the helper class for a given Repository ID.
49       */
50      public static String   className (String   repId, 
51                                      String   suffix, 
52                                      ClassLoader   loader)
53      {
54          if (repId.startsWith ("RMI:"))
55          {
56              return repId.substring (4, repId.indexOf (':', 4))
57                     + ( suffix != null ? suffix : "" );
58          }
59          else if (repId.startsWith ("IDL:"))
60          {
61              String   id = repId.substring (4, repId.lastIndexOf(':'))
62                          + ( suffix != null ? suffix : "" );
63              if (id.equals ("omg.org/CORBA/WStringValue"))
64                  return "java.lang.String";
65              else
66              {
67                  int    firstSlash = id.indexOf ("/");
68                  String   prefix     = id.substring (0, firstSlash);
69  
70                  if (prefix.equals ("omg.org"))
71                      return ir2scopes ("org.omg",
72                                        id.substring (firstSlash + 1),
73                                        loader);
74                  else if (prefix.indexOf ('.') != -1)
75                      return ir2scopes (reversePrefix (prefix),
76                                        id.substring (firstSlash + 1),
77                                        loader);
78                  else
79                      return ir2scopes ("", id, loader);
80              }
81          }
82          else
83          {
84             throw new INTF_REPOS   ("Unrecognized RepositoryID: " + repId);
85          }
86      }
87  
88      private static final String   reversePrefix (String   prefix)
89      {
90          StringTokenizer   tok    = new StringTokenizer   (prefix, ".");
91          String            result = tok.nextToken();
92  
93          while (tok.hasMoreTokens())
94          {
95              result = tok.nextToken() + '.' + result;
96          }
97          return result;
98      }
99  
100     /**
101      * FIXME: This method needs documentation.
102      * What does this algorithm do, and why is it necessary?  AS.
103      */
104     private static String   ir2scopes (String   prefix, 
105                                      String   s, 
106                                      ClassLoader   loader)
107     {
108         if( s.indexOf("/") < 0)
109             return s;
110         java.util.StringTokenizer   strtok =
111             new java.util.StringTokenizer  ( s, "/" );
112 
113         int count = strtok.countTokens();
114         StringBuffer   sb = new StringBuffer  ();
115         sb.append(prefix);
116 
117         for( int i = 0; strtok.hasMoreTokens(); i++ )
118         {
119             String   sc = strtok.nextToken();
120             Class   c = null;
121             if( sb.toString().length() > 0 )
122                 c = loadClass (sb.toString() + "." + sc, loader);
123             else
124                 c = loadClass (sc, loader);
125             if (c == null)
126                 if( sb.toString().length() > 0 )
127                     sb.append( "." + sc );
128                 else
129                     sb.append( sc );
130             else
131                 if( i < count-1)
132                     sb.append( "." + sc + "Package");
133                 else
134                     sb.append( "." + sc );
135         }
136 
137         return sb.toString();
138     }
139 
140     public static String   repId (Class   c)
141     {
142         if (org.omg.CORBA.portable.IDLEntity  .class.isAssignableFrom (c))
143         {
144             String   className = c.getName();
145             String   head = "";
146             String   body = "";
147 
148             // add "IDL:" and ":1.0"
149             // and swap "org.omg" if necessary
150 
151             if( className.startsWith("org.omg")  ||
152                 className.startsWith("org/omg") )
153             {
154                 if( className.length() > 7 )
155                     body = className.substring(7);
156                 return "IDL:omg.org/" + scopesToIR(body) + ":1.0";
157             }
158             else
159                 return "IDL:" + scopesToIR(className) + ":1.0" ;
160         }
161     else
162             return org.jacorb.util.ValueHandler.getRMIRepositoryID (c);
163     }
164 
165 
166     private static String   scopesToIR( String   s )
167     {
168         if( s.indexOf(".") < 0)
169             return s;
170         java.util.StringTokenizer   strtok =
171             new java.util.StringTokenizer  ( s, "." );
172 
173         String   scopes[] = new String  [strtok.countTokens()];
174 
175         for( int i = 0; strtok.hasMoreTokens(); i++ )
176         {
177             String   sc = strtok.nextToken();
178             if( sc.endsWith("Package"))
179                 scopes[i] = sc.substring(0,sc.indexOf("Package"));
180             else
181                 scopes[i] = sc;
182         }
183 
184         StringBuffer   sb = new StringBuffer  ();
185         if( scopes.length > 1 )
186         {
187             for( int i = 0; i < scopes.length-1; i++)
188                 sb.append( scopes[i] + "/" );
189         }
190 
191         sb.append( scopes[scopes.length-1] );
192         return sb.toString();
193     }
194 
195     /**
196      * Converts a class name to a Repository ID.
197      * @param classname the class name to convert
198      * @param resolveClass indicates whether the method should try to
199      * resolve and load the class. If true and the class could
200      * not be loaded, an IllegalArgumentException will be thrown
201      */
202     public static String   toRepositoryID ( String   className,
203                                           boolean resolveClass, 
204                                           ClassLoader   loader )
205     {
206         if( className.equals("") ||
207             className.startsWith("IDL:") ||
208             className.startsWith ("RMI:"))
209             return className;
210         else
211         {
212             if( resolveClass )
213             {
214 
215                 Class   c = loadClass(className, loader);
216                 if (c == null)
217                     throw new  IllegalArgumentException  ("cannot find class: " + className);
218                 else
219                     return repId (c);
220             }
221             return "IDL:" + className + ":1.0";
222         }
223     }
224 
225     public static String   toRepositoryID( String   className, ClassLoader   loader )
226     {
227         return toRepositoryID( className, true, loader );
228     }
229 
230     /**
231      * Loads class `name' using an appropriate class loader.
232      * Returns the corresponding class object, or null if the class loader
233      * cannot find a class by that name.
234      */
235     private static Class   loadClass (String   name, ClassLoader   loader)
236     {
237         try
238         {
239             if (loader != null)
240                 return loader.loadClass (name);
241             else
242                 return org.jacorb.util.ObjectUtil.classForName(name);
243         }
244         catch (ClassNotFoundException   e)
245         {
246             return null;
247         }
248     }
249 
250     /**
251      * Creates a BoxedValueHelper instance for a given repository ID.
252      * @param repId the repository ID of the boxed value type
253      * @return a newly created BoxedValueHelper, or null if no
254      *         BoxedValueHelper class can be found for that ID
255      * @throws RuntimeException if creation of the Helper instance fails
256      */
257     public static BoxedValueHelper   createBoxedValueHelper(String   repId, 
258                                                           ClassLoader   loader)
259     {
260         String   className = className(repId, "Helper", loader);
261         Class   c = loadClass(className, loader);
262         if (c != null)
263             try
264             {
265                 return (BoxedValueHelper  )c.newInstance();
266             }
267             catch (Exception   e)
268             {
269                 throw new RuntimeException  (e.toString());
270             }
271         else
272             return null;
273     }
274 }
275
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