1 /*
2 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/HttpParser.java,v 1.13 2005/01/11 13:57:06 oglueck Exp $
3 * $Revision: 533405 $
4 * $Date: 2007-04-28 20:19:29 +0200 (Sat, 28 Apr 2007) $
5 *
6 * ====================================================================
7 *
8 * Licensed to the Apache Software Foundation (ASF) under one or more
9 * contributor license agreements. See the NOTICE file distributed with
10 * this work for additional information regarding copyright ownership.
11 * The ASF licenses this file to You under the Apache License, Version 2.0
12 * (the "License"); you may not use this file except in compliance with
13 * the License. You may obtain a copy of the License at
14 *
15 * http://www.apache.org/licenses/LICENSE-2.0
16 *
17 * Unless required by applicable law or agreed to in writing, software
18 * distributed under the License is distributed on an "AS IS" BASIS,
19 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20 * See the License for the specific language governing permissions and
21 * limitations under the License.
22 * ====================================================================
23 *
24 * This software consists of voluntary contributions made by many
25 * individuals on behalf of the Apache Software Foundation. For more
26 * information on the Apache Software Foundation, please see
27 * <http://www.apache.org/>.
28 *
29 */
30
31 package org.apache.commons.httpclient;
32
33 import java.io.IOException;
34 import java.io.InputStream;
35 import java.io.ByteArrayOutputStream;
36 import java.util.ArrayList;
37
38 import org.apache.commons.httpclient.util.EncodingUtil;
39 import org.apache.commons.logging.Log;
40 import org.apache.commons.logging.LogFactory;
41
42 /**
43 * A utility class for parsing http header values according to
44 * RFC-2616 Section 4 and 19.3.
45 *
46 * @author Michael Becke
47 * @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
48 *
49 * @since 2.0beta1
50 */
51 public class HttpParser {
52
53 /** Log object for this class. */
54 private static final Log LOG = LogFactory.getLog(HttpParser.class);
55
56 /**
57 * Constructor for HttpParser.
58 */
59 private HttpParser() { }
60
61 /**
62 * Return byte array from an (unchunked) input stream.
63 * Stop reading when <tt>"\n"</tt> terminator encountered
64 * If the stream ends before the line terminator is found,
65 * the last part of the string will still be returned.
66 * If no input data available, <code>null</code> is returned.
67 *
68 * @param inputStream the stream to read from
69 *
70 * @throws IOException if an I/O problem occurs
71 * @return a byte array from the stream
72 */
73 public static byte[] readRawLine(InputStream inputStream) throws IOException {
74 LOG.trace("enter HttpParser.readRawLine()");
75
76 ByteArrayOutputStream buf = new ByteArrayOutputStream();
77 int ch;
78 while ((ch = inputStream.read()) >= 0) {
79 buf.write(ch);
80 if (ch == '\n') { // be tolerant (RFC-2616 Section 19.3)
81 break;
82 }
83 }
84 if (buf.size() == 0) {
85 return null;
86 }
87 return buf.toByteArray();
88 }
89
90 /**
91 * Read up to <tt>"\n"</tt> from an (unchunked) input stream.
92 * If the stream ends before the line terminator is found,
93 * the last part of the string will still be returned.
94 * If no input data available, <code>null</code> is returned.
95 *
96 * @param inputStream the stream to read from
97 * @param charset charset of HTTP protocol elements
98 *
99 * @throws IOException if an I/O problem occurs
100 * @return a line from the stream
101 *
102 * @since 3.0
103 */
104 public static String readLine(InputStream inputStream, String charset) throws IOException {
105 LOG.trace("enter HttpParser.readLine(InputStream, String)");
106 byte[] rawdata = readRawLine(inputStream);
107 if (rawdata == null) {
108 return null;
109 }
110 // strip CR and LF from the end
111 int len = rawdata.length;
112 int offset = 0;
113 if (len > 0) {
114 if (rawdata[len - 1] == '\n') {
115 offset++;
116 if (len > 1) {
117 if (rawdata[len - 2] == '\r') {
118 offset++;
119 }
120 }
121 }
122 }
123 final String result =
124 EncodingUtil.getString(rawdata, 0, len - offset, charset);
125 if (Wire.HEADER_WIRE.enabled()) {
126 String logoutput = result;
127 if (offset == 2)
128 logoutput = result + "\r\n";
129 else if (offset == 1)
130 logoutput = result + "\n";
131 Wire.HEADER_WIRE.input(logoutput);
132 }
133 return result;
134 }
135
136 /**
137 * Read up to <tt>"\n"</tt> from an (unchunked) input stream.
138 * If the stream ends before the line terminator is found,
139 * the last part of the string will still be returned.
140 * If no input data available, <code>null</code> is returned
141 *
142 * @param inputStream the stream to read from
143 *
144 * @throws IOException if an I/O problem occurs
145 * @return a line from the stream
146 *
147 * @deprecated use #readLine(InputStream, String)
148 */
149
150 public static String readLine(InputStream inputStream) throws IOException {
151 LOG.trace("enter HttpParser.readLine(InputStream)");
152 return readLine(inputStream, "US-ASCII");
153 }
154
155 /**
156 * Parses headers from the given stream. Headers with the same name are not
157 * combined.
158 *
159 * @param is the stream to read headers from
160 * @param charset the charset to use for reading the data
161 *
162 * @return an array of headers in the order in which they were parsed
163 *
164 * @throws IOException if an IO error occurs while reading from the stream
165 * @throws HttpException if there is an error parsing a header value
166 *
167 * @since 3.0
168 */
169 public static Header[] parseHeaders(InputStream is, String charset) throws IOException, HttpException {
170 LOG.trace("enter HeaderParser.parseHeaders(InputStream, String)");
171
172 ArrayList headers = new ArrayList();
173 String name = null;
174 StringBuffer value = null;
175 for (; ;) {
176 String line = HttpParser.readLine(is, charset);
177 if ((line == null) || (line.trim().length() < 1)) {
178 break;
179 }
180
181 // Parse the header name and value
182 // Check for folded headers first
183 // Detect LWS-char see HTTP/1.0 or HTTP/1.1 Section 2.2
184 // discussion on folded headers
185 if ((line.charAt(0) == ' ') || (line.charAt(0) == '\t')) {
186 // we have continuation folded header
187 // so append value
188 if (value != null) {
189 value.append(' ');
190 value.append(line.trim());
191 }
192 } else {
193 // make sure we save the previous name,value pair if present
194 if (name != null) {
195 headers.add(new Header(name, value.toString()));
196 }
197
198 // Otherwise we should have normal HTTP header line
199 // Parse the header name and value
200 int colon = line.indexOf(":");
201 if (colon < 0) {
202 throw new ProtocolException("Unable to parse header: " + line);
203 }
204 name = line.substring(0, colon).trim();
205 value = new StringBuffer(line.substring(colon + 1).trim());
206 }
207
208 }
209
210 // make sure we save the last name,value pair if present
211 if (name != null) {
212 headers.add(new Header(name, value.toString()));
213 }
214
215 return (Header[]) headers.toArray(new Header[headers.size()]);
216 }
217
218 /**
219 * Parses headers from the given stream. Headers with the same name are not
220 * combined.
221 *
222 * @param is the stream to read headers from
223 *
224 * @return an array of headers in the order in which they were parsed
225 *
226 * @throws IOException if an IO error occurs while reading from the stream
227 * @throws HttpException if there is an error parsing a header value
228 *
229 * @deprecated use #parseHeaders(InputStream, String)
230 */
231 public static Header[] parseHeaders(InputStream is) throws IOException, HttpException {
232 LOG.trace("enter HeaderParser.parseHeaders(InputStream, String)");
233 return parseHeaders(is, "US-ASCII");
234 }
235 }
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