1 /*
2 * $Header: /home/cvs/jakarta-commons/httpclient/src/java/org/apache/commons/httpclient/ContentLengthInputStream.java,v 1.6 2003/01/28 04:40:20 jsdever Exp $
3 * $Revision: 1.6 $
4 * $Date: 2003/01/28 04:40:20 $
5 *
6 * ====================================================================
7 *
8 * The Apache Software License, Version 1.1
9 *
10 * Copyright (c) 1999-2003 The Apache Software Foundation. All rights
11 * reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 *
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 *
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in
22 * the documentation and/or other materials provided with the
23 * distribution.
24 *
25 * 3. The end-user documentation included with the redistribution, if
26 * any, must include the following acknowlegement:
27 * "This product includes software developed by the
28 * Apache Software Foundation (http://www.apache.org/)."
29 * Alternately, this acknowlegement may appear in the software itself,
30 * if and wherever such third-party acknowlegements normally appear.
31 *
32 * 4. The names "The Jakarta Project", "Commons", and "Apache Software
33 * Foundation" must not be used to endorse or promote products derived
34 * from this software without prior written permission. For written
35 * permission, please contact apache@apache.org.
36 *
37 * 5. Products derived from this software may not be called "Apache"
38 * nor may "Apache" appear in their names without prior written
39 * permission of the Apache Group.
40 *
41 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
42 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
43 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
44 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
45 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
48 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
49 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
50 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
51 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * SUCH DAMAGE.
53 * ====================================================================
54 *
55 * This software consists of voluntary contributions made by many
56 * individuals on behalf of the Apache Software Foundation. For more
57 * information on the Apache Software Foundation, please see
58 * <http://www.apache.org/>.
59 *
60 * [Additional notices, if required by prior licensing conditions]
61 *
62 */
63
64 package org.apache.commons.httpclient;
65
66 import java.io.FilterInputStream;
67 import java.io.IOException;
68 import java.io.InputStream;
69
70 /***
71 * Cuts the wrapped InputStream off after a specified number of bytes.
72 *
73 * @author Ortwin Gl�ck
74 * @author Eric Johnson
75 * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
76 * @since 2.0
77 */
78
79 public class ContentLengthInputStream extends FilterInputStream {
80
81 /***
82 * The maximum number of bytes that can be read from the stream. Subsequent
83 * read operations will return -1.
84 */
85 private int contentLength;
86
87 /*** The current position */
88 private int pos = 0;
89
90 /*** True if the stream is closed. */
91 private boolean closed = false;
92
93 /***
94 * Creates a new length limited stream
95 *
96 * @param in The stream to wrap
97 * @param contentLength The maximum number of bytes that can be read from
98 * the stream. Subsequent read operations will return -1.
99 */
100 public ContentLengthInputStream(InputStream in, int contentLength) {
101 super(in);
102 this.contentLength = contentLength;
103 }
104
105 /***
106 * <p>Reads until the end of the known length of content.</p>
107 *
108 * <p>Does not close the underlying socket input, but instead leaves it
109 * primed to parse the next response.</p>
110 * @throws IOException If an IO problem occurs.
111 */
112 public void close() throws IOException {
113 if (!closed) {
114 try {
115 ChunkedInputStream.exhaustInputStream(this);
116 } finally {
117 // close after above so that we don't throw an exception trying
118 // to read after closed!
119 closed = true;
120 }
121 }
122 }
123
124
125 /***
126 * Read the next byte from the stream
127 * @return The next byte or -1 if the end of stream has been reached.
128 * @throws IOException If an IO problem occurs
129 * @see java.io.InputStream#read()
130 */
131 public int read() throws IOException {
132 if (closed) {
133 throw new IOException("Attempted read from closed stream.");
134 }
135
136 if (pos >= contentLength) {
137 return -1;
138 }
139 pos++;
140 return super.read();
141 }
142
143 /***
144 * Does standard {@link InputStream#read(byte[], int, int)} behavior, but
145 * also notifies the watcher when the contents have been consumed.
146 *
147 * @param b The byte array to fill.
148 * @param off Start filling at this position.
149 * @param len The number of bytes to attempt to read.
150 * @return The number of bytes read, or -1 if the end of content has been
151 * reached.
152 *
153 * @throws java.io.IOException Should an error occur on the wrapped stream.
154 */
155 public int read (byte[] b, int off, int len) throws java.io.IOException {
156 if (closed) {
157 throw new IOException("Attempted read from closed stream.");
158 }
159
160 if (pos >= contentLength) {
161 return -1;
162 }
163
164 if (pos + len > contentLength) {
165 len = contentLength - pos;
166 }
167 int count = super.read(b, off, len);
168 pos += count;
169 return count;
170 }
171
172
173 /***
174 * Read more bytes from the stream.
175 * @param b The byte array to put the new data in.
176 * @return The number of bytes read into the buffer.
177 * @throws IOException If an IO problem occurs
178 * @see java.io.InputStream#read(byte[])
179 */
180 public int read(byte[] b) throws IOException {
181 return read(b, 0, b.length);
182 }
183
184 }
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