Mercurial > hg > blitz_condensed
comparison src/com/go/trove/io/PositionReader.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 21 Mar 2009 11:00:06 +0000 |
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-1:000000000000 | 0:3dc0c5604566 |
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1 /* ==================================================================== | |
2 * Trove - Copyright (c) 1997-2000 Walt Disney Internet Group | |
3 * ==================================================================== | |
4 * The Tea Software License, Version 1.1 | |
5 * | |
6 * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved. | |
7 * | |
8 * Redistribution and use in source and binary forms, with or without | |
9 * modification, are permitted provided that the following conditions | |
10 * are met: | |
11 * | |
12 * 1. Redistributions of source code must retain the above copyright | |
13 * notice, this list of conditions and the following disclaimer. | |
14 * | |
15 * 2. Redistributions in binary form must reproduce the above copyright | |
16 * notice, this list of conditions and the following disclaimer in | |
17 * the documentation and/or other materials provided with the | |
18 * distribution. | |
19 * | |
20 * 3. The end-user documentation included with the redistribution, | |
21 * if any, must include the following acknowledgment: | |
22 * "This product includes software developed by the | |
23 * Walt Disney Internet Group (http://opensource.go.com/)." | |
24 * Alternately, this acknowledgment may appear in the software itself, | |
25 * if and wherever such third-party acknowledgments normally appear. | |
26 * | |
27 * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must | |
28 * not be used to endorse or promote products derived from this | |
29 * software without prior written permission. For written | |
30 * permission, please contact opensource@dig.com. | |
31 * | |
32 * 5. Products derived from this software may not be called "Tea", | |
33 * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet", | |
34 * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior | |
35 * written permission of the Walt Disney Internet Group. | |
36 * | |
37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED | |
38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
40 * DISCLAIMED. IN NO EVENT SHALL THE WALT DISNEY INTERNET GROUP OR ITS | |
41 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | |
42 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | |
43 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | |
44 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY | |
45 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
46 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
47 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
48 * ==================================================================== | |
49 * | |
50 * For more information about Tea, please see http://opensource.go.com/. | |
51 */ | |
52 | |
53 package com.go.trove.io; | |
54 | |
55 import java.io.*; | |
56 | |
57 /****************************************************************************** | |
58 * The PositionReader tracks the postion in the stream of the next character | |
59 * to be read. PositionReaders chain together such that the position is | |
60 * read from the earliest PositionReader in the chain. | |
61 * | |
62 * <p>Position readers automatically close the underlying input stream when | |
63 * the end of file is reached. Ordinary input streams don't do this. | |
64 * | |
65 * @author Brian S O'Neill | |
66 * @version | |
67 * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 12/11/00 <!-- $--> | |
68 */ | |
69 public class PositionReader extends FilterReader { | |
70 /** Is non-null when this PositionReader is chained to another. */ | |
71 protected PositionReader mPosReader; | |
72 | |
73 protected int mPosition = 0; | |
74 | |
75 private boolean mClosed = false; | |
76 | |
77 public PositionReader(Reader reader) { | |
78 super(reader); | |
79 if (reader instanceof PositionReader) { | |
80 mPosReader = (PositionReader)reader; | |
81 } | |
82 } | |
83 | |
84 /** | |
85 * @return the position of the next character to be read. | |
86 */ | |
87 public int getNextPosition() { | |
88 return mPosition; | |
89 } | |
90 | |
91 public int read() throws IOException { | |
92 try { | |
93 int c; | |
94 if ((c = in.read()) != -1) { | |
95 if (mPosReader == null) { | |
96 mPosition++; | |
97 } | |
98 else { | |
99 mPosition = mPosReader.getNextPosition(); | |
100 } | |
101 } | |
102 else { | |
103 close(); | |
104 } | |
105 | |
106 return c; | |
107 } | |
108 catch (IOException e) { | |
109 if (mClosed) { | |
110 return -1; | |
111 } | |
112 else { | |
113 throw e; | |
114 } | |
115 } | |
116 } | |
117 | |
118 public int read(char[] buf, int off, int length) throws IOException { | |
119 int i = 0; | |
120 while (i < length) { | |
121 int c; | |
122 if ((c = read()) == -1) { | |
123 return (i == 0)? -1 : i; | |
124 } | |
125 buf[i++ + off] = (char)c; | |
126 } | |
127 | |
128 return i; | |
129 } | |
130 | |
131 public void close() throws IOException { | |
132 mClosed = true; | |
133 super.close(); | |
134 } | |
135 } |