MeasurableInputStream


1   package it.unimi.dsi.fastutil.io;
2   
3   /*       
4    * fastutil: Fast & compact type-specific collections for Java
5    *
6    * Copyright (C) 2006 Sebastiano Vigna 
7    *
8    *  This library is free software; you can redistribute it and/or
9    *  modify it under the terms of the GNU Lesser General Public
10   *  License as published by the Free Software Foundation; either
11   *  version 2.1 of the License, or (at your option) any later version.
12   *
13   *  This library is distributed in the hope that it will be useful,
14   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16   *  Lesser General Public License for more details.
17   *
18   *  You should have received a copy of the GNU Lesser General Public
19   *  License along with this library; if not, write to the Free Software
20   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21   *
22   */
23  
24  
25  import java.io.IOException  ;
26  import java.io.InputStream  ;
27  
28  /** An {@link java.io.InputStream} that provides eager access to its length,
29   * and keeps track of the current position (e.g., the number of bytes read so far). 
30   *
31   * <P>This class adds two methods, both specified as optional. This apparently bizarre
32   * behaviour is necessary because of wrapper classes which use reflection 
33   * to support those methods (see, e.g., {@link FastBufferedInputStream}).
34   *
35   * @since 5.0.4
36   */
37  
38  public abstract class MeasurableInputStream extends InputStream   {
39      
40      /** Returns the overall length of this input stream (optional operation). In most cases, this will require the input
41       *  stream to perform some extra action, possibly changing the state of the input stream itself (typically, reading
42       *  all the bytes up to the end).
43       *  Implementing classes should always document what state will the input stream be in
44       *  after calling this method, and which kind of exception could be thrown.
45       */ 
46      public abstract long length() throws IOException  ;
47  
48      /** Returns the current position in this input stream (optional operation).
49       * 
50       * <p>Usually, the position is just the number of bytes read
51       * since the stream was opened, but in the case of a
52       * {@link it.unimi.dsi.fastutil.io.RepositionableStream} it
53       * represent the current position.
54       */ 
55      public abstract long position() throws IOException  ;
56  }
57
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags