1 /**
2 * Copyright 2005-2011 The Kuali Foundation
3 *
4 * Licensed under the Educational Community License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.opensource.org/licenses/ecl2.php
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.kuali.rice.ken.util;
17
18 import java.io.IOException;
19 import java.util.ArrayList;
20 import java.util.List;
21
22 import org.apache.log4j.Logger;
23 import org.xml.sax.EntityResolver;
24 import org.xml.sax.InputSource;
25 import org.xml.sax.SAXException;
26
27 /**
28 * EntityResolver implementation that delegates in sequence to a list of EntityResolvers,
29 * returning the first match.
30 * @author Kuali Rice Team (rice.collab@kuali.org)
31 */
32 public class CompoundEntityResolver implements EntityResolver {
33 private static final Logger LOG = Logger.getLogger(CompoundEntityResolver.class);
34
35 private final List<EntityResolver> resolvers;
36
37 /**
38 * Constructs a CompoundEntityResolver.java.
39 * @param first
40 * @param second
41 */
42 public CompoundEntityResolver(EntityResolver first, EntityResolver second) {
43 this.resolvers = new ArrayList<EntityResolver>(2);
44 this.resolvers.add(first);
45 this.resolvers.add(second);
46 }
47
48 /**
49 * Constructs a CompoundEntityResolver.java.
50 * @param resolvers
51 */
52 public CompoundEntityResolver(List<EntityResolver> resolvers) {
53 this.resolvers = resolvers;
54 }
55
56 /**
57 * @see org.xml.sax.EntityResolver#resolveEntity(java.lang.String, java.lang.String)
58 */
59 public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
60 LOG.debug("resolveEntity: " + publicId + " " + systemId);
61 for (EntityResolver resolver: resolvers) {
62 LOG.debug("Invoking entity resolver: " + resolver);
63 InputSource source = resolver.resolveEntity(publicId, systemId);
64 if (source != null) {
65 LOG.debug("source != null: " + source);
66 return source;
67 }
68 }
69 return null;
70 }
71 }