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1   /****************************************************************
2    * Licensed to the Apache Software Foundation (ASF) under one   *
3    * or more contributor license agreements.  See the NOTICE file *
4    * distributed with this work for additional information        *
5    * regarding copyright ownership.  The ASF licenses this file   *
6    * to you under the Apache License, Version 2.0 (the            *
7    * "License"); you may not use this file except in compliance   *
8    * with the License.  You may obtain a copy of the License at   *
9    *                                                              *
10   *   http://www.apache.org/licenses/LICENSE-2.0                 *
11   *                                                              *
12   * Unless required by applicable law or agreed to in writing,   *
13   * software distributed under the License is distributed on an  *
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
15   * KIND, either express or implied.  See the License for the    *
16   * specific language governing permissions and limitations      *
17   * under the License.                                           *
18   ****************************************************************/
19  
20  
21  package org.apache.james.mime4j.io;
22  
23  import java.io.FilterInputStream;
24  import java.io.InputStream;
25  import java.io.IOException;
26  
27  public class PositionInputStream extends FilterInputStream {
28  
29      protected long position = 0;
30      private long markedPosition = 0;
31  
32      public PositionInputStream(InputStream inputStream) {
33          super(inputStream);
34      }
35  
36      public long getPosition() {
37          return position;
38      }
39  
40      @Override
41      public int available() throws IOException {
42          return in.available();
43      }
44  
45      @Override
46      public int read() throws IOException {
47          int b = in.read();
48          if (b != -1)
49              position++;
50          return b;
51      }
52  
53      @Override
54      public void close() throws IOException {
55          in.close();
56      }
57  
58      @Override
59      public void reset() throws IOException {
60          in.reset();
61          position = markedPosition;
62      }
63  
64      @Override
65      public boolean markSupported() {
66          return in.markSupported();
67      }
68  
69      @Override
70      public void mark(int readlimit) {
71          in.mark(readlimit);
72          markedPosition = position;
73      }
74  
75      @Override
76      public long skip(long n) throws IOException {
77          final long c = in.skip(n);
78          if (c > 0) 
79              position += c;
80          return c;
81      }
82  
83      @Override
84      public int read(byte b[], int off, int len) throws IOException {
85          final int c = in.read(b, off, len);
86          if (c > 0) 
87              position += c;
88          return c;
89      }
90  
91  }