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    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 }