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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    * 
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   * 
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.vfs.util;
18  
19  import java.io.BufferedOutputStream;
20  import java.io.IOException;
21  import java.io.OutputStream;
22  
23  /***
24   * An OutputStream that provides buffering and end-of-stream monitoring.
25   *
26   * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
27   * @version $Revision: 480428 $ $Date: 2006-11-29 07:15:24 +0100 (Mi, 29 Nov 2006) $
28   */
29  public class MonitorOutputStream
30      extends BufferedOutputStream
31  {
32      private boolean finished;
33  
34      public MonitorOutputStream(final OutputStream out)
35      {
36          super(out);
37      }
38  
39      /***
40       * Closes this output stream.
41       */
42      public void close() throws IOException
43      {
44          if (finished)
45          {
46              return;
47          }
48  
49          // Close the output stream
50          IOException exc = null;
51          try
52          {
53              super.close();
54          }
55          catch (final IOException ioe)
56          {
57              exc = ioe;
58          }
59  
60          // Notify of end of output
61          try
62          {
63              onClose();
64          }
65          catch (final IOException ioe)
66          {
67              exc = ioe;
68          }
69  
70          finished = true;
71  
72          if (exc != null)
73          {
74              throw exc;
75          }
76      }
77  
78      /***
79       * Called after this stream is closed.  This implementation does nothing.
80       */
81      protected void onClose() throws IOException
82      {
83      }
84  }