1 /**
2 * Redistribution and use of this software and associated documentation
3 * ("Software"), with or without modification, are permitted provided
4 * that the following conditions are met:
5 *
6 * 1. Redistributions of source code must retain copyright
7 * statements and notices. Redistributions must also contain a
8 * copy of this document.
9 *
10 * 2. Redistributions in binary form must reproduce the
11 * above copyright notice, this list of conditions and the
12 * following disclaimer in the documentation and/or other
13 * materials provided with the distribution.
14 *
15 * 3. The name "Exolab" must not be used to endorse or promote
16 * products derived from this Software without prior written
17 * permission of Intalio, Inc. For written permission,
18 * please contact info@exolab.org.
19 *
20 * 4. Products derived from this Software may not be called "Exolab"
21 * nor may "Exolab" appear in their names without prior written
22 * permission of Intalio, Inc. Exolab is a registered
23 * trademark of Intalio, Inc.
24 *
25 * 5. Due credit should be given to the Exolab Project
26 * (http://www.exolab.org/).
27 *
28 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
32 * INTALIO, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39 * OF THE POSSIBILITY OF SUCH DAMAGE.
40 *
41 * Copyright 1999 (C) Intalio, Inc. All Rights Reserved.
42 *
43 * $Id$
44 */
45
46 package org.exolab.castor.xml.schema;
47
48 import java.util.Hashtable;
49
50 /**
51 * An implementation of Resolver that can be "scoped". Which means you
52 * can construct a ScopableResovler and give it another Resolver (which
53 * can also be Scopable). If this Resolver cannot "resolve" the id, then
54 * it will try to use the given Resolver to resolver it.
55 * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
56 * @version $Revision$ $Date: 2006-04-13 06:47:36 -0600 (Thu, 13 Apr 2006) $
57 **/
58 public class ScopableResolver implements Resolver {
59
60 private Hashtable ids;
61
62 private Resolver _resolver = null;
63
64 public ScopableResolver() {
65 ids = new Hashtable();
66 } //-- ScopableResolver
67
68 public ScopableResolver(Resolver resolver) {
69 this();
70 _resolver = resolver;
71 } //-- ScopableResolver
72
73 /**
74 * Adds a resolvable object to this resolver identified by <tt>id</tt>.
75 * Subsequent calls to {@link #resolve} with the same <tt>id</tt>
76 * will return <tt>referent</tt>.
77 *
78 * @param id The referent's identifier
79 * @param referent The referent object
80 */
81 public void addResolvable( String id, Referable referent ) {
82 if (ids.get(id) != null) {
83 //-- handle error
84 }
85 ids.put(id, referent);
86 } //-- register
87
88 /**
89 * Removes a resolvable object from this resolver. Subsequent calls
90 * to {@link #resolve} with the same <tt>id</tt> will return null.
91 *
92 * @param id The referent's identifier
93 */
94 public void removeResolvable( String id ) {
95 Object obj = ids.get(id);
96 if (obj != null) {
97 ids.remove(id);
98 }
99 } //-- removeResolvable
100
101 public Referable resolve(String id) {
102 Referable referable = (Referable) ids.get(id);
103 if ((referable == null) && (_resolver != null)) {
104 referable = _resolver.resolve(id);
105 }
106 return referable;
107 } //-- resolve
108
109
110 } //-- ScopableResolver