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1   /*
2    * Copyright 2008 University Corporation for Advanced Internet Development, Inc.
3    *
4    * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
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  
17  package org.opensaml.util.resource;
18  
19  import java.io.InputStream;
20  
21  import org.slf4j.Logger;
22  import org.slf4j.LoggerFactory;
23  
24  /** A {@link Resource} whose contents may be run through a filter as it is being read. */
25  public abstract class AbstractFilteredResource implements Resource {
26      
27      /** Class logger. */
28      private final Logger log = LoggerFactory.getLogger(AbstractFilteredResource.class);
29  
30      /** Associated resource filter. */
31      private ResourceFilter resourceFilter;
32  
33      /** Constructor. */
34      protected AbstractFilteredResource() {
35  
36      }
37  
38      /**
39       * Constructor.
40       * 
41       * @param filter the filter used on the resource
42       * 
43       * @deprecated use {@link #setResourceFilter(ResourceFilter)} instead
44       */
45      protected AbstractFilteredResource(ResourceFilter filter) {
46          resourceFilter = filter;
47      }
48  
49      /**
50       * Gets the resource filter associated with this resource.
51       * 
52       * @return resource filter associated with this resource
53       */
54      public ResourceFilter getResourceFilter() {
55          return resourceFilter;
56      }
57      
58      /**
59       * Sets the resource filter associated with this resource.
60       * 
61       * @param filter filter associated with this resource
62       */
63      public void setResourceFilter(ResourceFilter filter){
64          resourceFilter = filter;
65      }
66  
67      /**
68       * Applies the filter to the given stream resulting in the returned stream. If no filter is set than the given
69       * stream is the returned stream.
70       * 
71       * @param stream the stream to filter
72       * 
73       * @return the filtered stream
74       * 
75       * @throws ResourceException thrown if the filter can not be applied to the stream
76       */
77      protected InputStream applyFilter(InputStream stream) throws ResourceException {
78          ResourceFilter filter = getResourceFilter();
79          if (filter != null) {
80              log.debug("Apply filter '{}' to resource '{}'", filter.getClass(), this.getLocation());
81              return getResourceFilter().applyFilter(stream);
82          } else {
83              return stream;
84          }
85      }
86  }