1 /**
2 * Redistribution and use of this software and associated documentation ("Software"), with or
3 * without modification, are permitted provided that the following conditions are met:
4 *
5 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions
6 * must also contain a copy of this document.
7 *
8 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
9 * conditions and the following disclaimer in the documentation and/or other materials provided with
10 * the distribution.
11 *
12 * 3. The name "Exolab" must not be used to endorse or promote products derived from this Software
13 * without prior written permission of Intalio, Inc. For written permission, please contact
14 * info@exolab.org.
15 *
16 * 4. Products derived from this Software may not be called "Exolab" nor may "Exolab" appear in
17 * their names without prior written permission of Intalio, Inc. Exolab is a registered trademark of
18 * Intalio, Inc.
19 *
20 * 5. Due credit should be given to the Exolab Project (http://www.exolab.org/).
21 *
22 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
24 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTALIO, INC. OR ITS
25 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
28 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
29 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 * Copyright 1999 (C) Intalio, Inc. All Rights Reserved.
32 *
33 * $Id$
34 */
35
36 package org.exolab.castor.xml.schema;
37
38 import java.util.Hashtable;
39
40 /**
41 * An implementation of Resolver that can be "scoped". Which means you can construct a
42 * ScopableResovler and give it another Resolver (which can also be Scopable). If this Resolver
43 * cannot "resolve" the id, then it will try to use the given Resolver to resolver it.
44 *
45 * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
46 * @version $Revision$ $Date: 2006-04-13 06:47:36 -0600 (Thu, 13 Apr 2006) $
47 **/
48 public class ScopableResolver implements Resolver {
49
50 private final Hashtable<String, Referable> ids = new Hashtable<>();
51
52 private final Resolver _resolver;
53
54 public ScopableResolver() {
55 this(null);
56 } // -- ScopableResolver
57
58 public ScopableResolver(Resolver resolver) {
59 _resolver = resolver;
60 } // -- ScopableResolver
61
62 /**
63 * Adds a resolvable object to this resolver identified by <tt>id</tt>. Subsequent calls to
64 * {@link #resolve} with the same <tt>id</tt> will return <tt>referent</tt>.
65 *
66 * @param id The referent's identifier
67 * @param referent The referent object
68 */
69 public void addResolvable(String id, Referable referent) {
70 if (ids.get(id) != null) {
71 // -- handle error
72 }
73 ids.put(id, referent);
74 } // -- register
75
76 /**
77 * Removes a resolvable object from this resolver. Subsequent calls to {@link #resolve} with the
78 * same <tt>id</tt> will return null.
79 *
80 * @param id The referent's identifier
81 */
82 public void removeResolvable(String id) {
83 Object obj = ids.get(id);
84 if (obj != null) {
85 ids.remove(id);
86 }
87 } // -- removeResolvable
88
89 public Referable resolve(String id) {
90 Referable referable = (Referable) ids.get(id);
91 if ((referable == null) && (_resolver != null)) {
92 referable = _resolver.resolve(id);
93 }
94 return referable;
95 } // -- resolve
96
97
98 } // -- ScopableResolver