View Javadoc

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  package org.apache.mina.core.file;
21  
22  import java.io.IOException;
23  import java.nio.channels.FileChannel;
24  
25  
26  /**
27   * TODO Add documentation
28   * 
29   * 
30   * @author The Apache MINA Project (dev@mina.apache.org)
31   * @version $Rev$, $Date$
32   */
33  public class DefaultFileRegion implements FileRegion {
34  
35      private final FileChannel channel;
36  
37      private final long originalPosition;
38      private long position;
39      private long remainingBytes;
40  
41      public DefaultFileRegion(FileChannel channel) throws IOException {
42          this(channel, 0, channel.size());
43      }
44      
45      public DefaultFileRegion(FileChannel channel, long position, long remainingBytes) {
46          if (channel == null) {
47              throw new IllegalArgumentException("channel can not be null");
48          }
49          if (position < 0) {
50              throw new IllegalArgumentException("position may not be less than 0");
51          }
52          if (remainingBytes < 0) {
53              throw new IllegalArgumentException("remainingBytes may not be less than 0");
54          }
55          this.channel = channel;
56          this.originalPosition = position;
57          this.position = position;
58          this.remainingBytes = remainingBytes;
59      }
60  
61      public long getWrittenBytes() {
62          return position - originalPosition;
63      }
64  
65      public long getRemainingBytes() {
66          return remainingBytes;
67      }
68  
69      public FileChannel getFileChannel() {
70          return channel;
71      }
72  
73      public long getPosition() {
74          return position;
75      }
76  
77      public void update(long value) {
78          position += value;
79          remainingBytes -= value;
80      }
81  
82  }