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comparison src/com/go/trove/io/PositionReader.java @ 0:3dc0c5604566

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Initial checkin of blitz 2.0 fcs - no installer yet.
author Dan Creswell <dan.creswell@gmail.com>
date Sat, 21 Mar 2009 11:00:06 +0000
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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 }