1 /*
2 * Copyright (c) 1996, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package sun.rmi.transport.proxy;
26
27 import java.io.*;
28
29 import sun.rmi.runtime.Log;
30
31 /**
32 * The HttpInputStream class assists the HttpSendSocket and HttpReceiveSocket
33 * classes by filtering out the header for the message as well as any
34 * data after its proper content length.
35 */
36 class HttpInputStream extends FilterInputStream {
37
38 /** bytes remaining to be read from proper content of message */
39 protected int bytesLeft;
40
41 /** bytes remaining to be read at time of last mark */
42 protected int bytesLeftAtMark;
43
44 /**
45 * Create new filter on a given input stream.
46 * @param in the InputStream to filter from
47 */
48 @SuppressWarnings("deprecation")
49 public HttpInputStream(InputStream in) throws IOException
50 {
51 super(in);
52
53 if (in.markSupported())
54 in.mark(0); // prevent resetting back to old marks
55
56 // pull out header, looking for content length
57
58 DataInputStream dis = new DataInputStream(in);
59 String key = "Content-length:".toLowerCase();
60 boolean contentLengthFound = false;
61 String line;
62 do {
63 line = dis.readLine();
64
65 if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
66 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
67 "received header line: \"" + line + "\"");
68 }
69
70 if (line == null)
71 throw new EOFException();
72
73 if (line.toLowerCase().startsWith(key)) {
74 if (contentLengthFound) {
75 throw new IOException(
76 "Multiple Content-length entries found.");
77 } else {
78 bytesLeft =
79 Integer.parseInt(line.substring(key.length()).trim());
80 contentLengthFound = true;
81 }
82 }
83
84 // The idea here is to go past the first blank line.
85 // Some DataInputStream.readLine() documentation specifies that
86 // it does include the line-terminating character(s) in the
87 // returned string, but it actually doesn't, so we'll cover
88 // all cases here...
89 } while ((line.length() != 0) &&
90 (line.charAt(0) != '\r') && (line.charAt(0) != '\n'));
91
92 if (!contentLengthFound || bytesLeft < 0) {
93 // This really shouldn't happen, but if it does, shoud we fail??
94 // For now, just give up and let a whole lot of bytes through...
95 bytesLeft = Integer.MAX_VALUE;
96 }
97 bytesLeftAtMark = bytesLeft;
98
99 if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
100 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
101 "content length: " + bytesLeft);
102 }
103 }
104
105 /**
106 * Returns the number of bytes that can be read with blocking.
107 * Make sure that this does not exceed the number of bytes remaining
108 * in the proper content of the message.
109 */
110 public int available() throws IOException
111 {
112 int bytesAvailable = in.available();
113 if (bytesAvailable > bytesLeft)
114 bytesAvailable = bytesLeft;
115
116 return bytesAvailable;
117 }
118
119 /**
120 * Read a byte of data from the stream. Make sure that one is available
121 * from the proper content of the message, else -1 is returned to
122 * indicate to the user that the end of the stream has been reached.
123 */
124 public int read() throws IOException
125 {
126 if (bytesLeft > 0) {
127 int data = in.read();
128 if (data != -1)
129 -- bytesLeft;
130
131 if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
132 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
133 "received byte: '" +
134 ((data & 0x7F) < ' ' ? " " : String.valueOf((char) data)) +
135 "' " + data);
136 }
137
138 return data;
139 }
140 else {
141 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
142 "read past content length");
143
144 return -1;
145 }
146 }
147
148 public int read(byte b[], int off, int len) throws IOException
149 {
150 if (bytesLeft == 0 && len > 0) {
151 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
152 "read past content length");
153
154 return -1;
155 }
156 if (len > bytesLeft)
157 len = bytesLeft;
158 int bytesRead = in.read(b, off, len);
159 bytesLeft -= bytesRead;
160
161 if (RMIMasterSocketFactory.proxyLog.isLoggable(Log.VERBOSE)) {
162 RMIMasterSocketFactory.proxyLog.log(Log.VERBOSE,
163 "read " + bytesRead + " bytes, " + bytesLeft + " remaining");
164 }
165
166 return bytesRead;
167 }
168
169 /**
170 * Mark the current position in the stream (for future calls to reset).
171 * Remember where we are within the proper content of the message, so
172 * that a reset method call can recreate our state properly.
173 * @param readlimit how many bytes can be read before mark becomes invalid
174 */
175 public void mark(int readlimit)
176 {
177 in.mark(readlimit);
178 if (in.markSupported())
179 bytesLeftAtMark = bytesLeft;
180 }
181
182 /**
183 * Repositions the stream to the last marked position. Make sure to
184 * adjust our position within the proper content accordingly.
185 */
186 public void reset() throws IOException
187 {
188 in.reset();
189 bytesLeft = bytesLeftAtMark;
190 }
191
192 /**
193 * Skips bytes of the stream. Make sure to adjust our
194 * position within the proper content accordingly.
195 * @param n number of bytes to be skipped
196 */
197 public long skip(long n) throws IOException
198 {
199 if (n > bytesLeft)
200 n = bytesLeft;
201 long bytesSkipped = in.skip(n);
202 bytesLeft -= bytesSkipped;
203 return bytesSkipped;
204 }
205 }