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1   /*
2    * Licensed to The Apereo Foundation under one or more contributor license
3    * agreements. See the NOTICE file distributed with this work for additional
4    * information regarding copyright ownership.
5    *
6    *
7    * The Apereo Foundation licenses this file to you under the Educational
8    * Community License, Version 2.0 (the "License"); you may not use this file
9    * except in compliance with the License. You may obtain a copy of the License
10   * at:
11   *
12   *   http://opensource.org/licenses/ecl2.txt
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
16   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
17   * License for the specific language governing permissions and limitations under
18   * the License.
19   *
20   */
21  
22  package org.opencastproject.ingest.impl;
23  
24  import com.google.common.base.Preconditions;
25  
26  import java.io.FilterInputStream;
27  import java.io.IOException;
28  import java.io.InputStream;
29  
30  public class ZipEntryInputStream extends FilterInputStream {
31  
32    /** Length of the zip entry */
33    private long bytesToRead = 0;
34  
35    /**
36     * Creates a wrapper around the input stream <code>in</code> and reads the given number of bytes from it.
37     *
38     * @param in
39     *          the input stream
40     * @param length
41     *          the number of bytes to read
42     */
43    public ZipEntryInputStream(InputStream in, long length) {
44      super(in);
45      bytesToRead = length;
46      Preconditions.checkNotNull(in);
47    }
48  
49    @Override
50    public int read() throws IOException {
51      if (bytesToRead == 0)
52        return -1;
53      bytesToRead--;
54      int byteContent = in.read();
55      if (byteContent == -1)
56        throw new IOException("Zip entry is shorter than anticipated");
57      return byteContent;
58    }
59  
60    @Override
61    public void close() throws IOException {
62      // This stream mustn't be closed because it handles the Zip entry parts of the given Zip input stream
63      // make sure the given zip input stream is closed after reading
64    }
65  
66  }