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1   /**
2    * Copyright 2005-2012 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.io.InputStream;
20  
21  import org.xml.sax.EntityResolver;
22  import org.xml.sax.InputSource;
23  import org.xml.sax.SAXException;
24  
25  /**
26   * Internal notification EntityResolver which resolves system ids with the "resource:" prefix to ClassLoader resources
27   * @author Kuali Rice Team (rice.collab@kuali.org)
28   */
29  public class ClassLoaderEntityResolver extends ClassLoaderResourceResolver implements EntityResolver {
30      /**
31       * Constructs a ClassLoaderEntityResolver.java.
32       */
33      public ClassLoaderEntityResolver() {
34          super();
35      }
36  
37      /**
38       * Constructs a ClassLoaderEntityResolver.java.
39       * @param base
40       * @param prefix
41       */
42      public ClassLoaderEntityResolver(String base, String prefix) {
43          super(base, prefix);
44      }
45      
46      /**
47       * @see org.xml.sax.EntityResolver#resolveEntity(java.lang.String, java.lang.String)
48       */
49      public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
50          LOG.debug("Resolving '" + publicId + "' / '" + systemId + "'");
51          String path = resolveSystemId(systemId);
52          if (path == null) {
53              LOG.error("Unable to resolve system id '" + systemId + "' locally...delegating to default resolution strategy.");
54              return null;
55          }
56          LOG.debug("Looking up resource '" + path + "' for entity '" + systemId + "'");
57          InputStream is = getClass().getClassLoader().getResourceAsStream(path);
58          if (is == null) {
59              String message = "Unable to find schema (" + path + ") for: " + systemId;
60              LOG.warn(message);
61              // necessary if processContents is lax, because lax doesn't care...if it doesn't resolve it won't validate
62              // (not quite clear, as lax could be interpreted as *if the namespace is valid*, treating a present, but invalid
63              // namespace as a fatal error. instead, apparently a present but invalid namespace is ignored with 'lax'
64              // so w should use strict to ensure that is an error instead of throwing an exception here gratuitously
65              // which will screw up compound resolution
66              //throw new SAXException(message);
67              return null;
68          }
69          return new InputSource(is);
70      }
71  
72      /**
73       * @see java.lang.Object#toString()
74       */
75      public String toString() {
76          return "[ClassLoaderEntityResolver: base=" + base + ", prefix=" + prefix + "]";
77      }
78  }