    1   /* MimetypeUtils
    2    *
    3    * $Id: MimetypeUtils.java 3119 2005-02-17 20:39:21Z stack-sf $
    4    *
    5    * Created on Sep 22, 2004
    6    *
    7    * Copyright (C) 2004 Internet Archive.
    8    *
    9    * This file is part of the Heritrix web crawler (crawler.archive.org).
    10   *
    11   * Heritrix is free software; you can redistribute it and/or modify
    12   * it under the terms of the GNU Lesser Public License as published by
    13   * the Free Software Foundation; either version 2.1 of the License, or
    14   * any later version.
    15   *
    16   * Heritrix is distributed in the hope that it will be useful,
    17   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    18   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    19   * GNU Lesser Public License for more details.
    20   *
    21   * You should have received a copy of the GNU Lesser Public License
    22   * along with Heritrix; if not, write to the Free Software
    23   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    24   */
    25  package org.archive.util;
    26
    27  import java.util.regex.Matcher;
    28  import java.util.regex.Pattern;
    29
    30  /***
    31   * Class of mimetype utilities.
    32   * @author stack
    33   */
    34  public class MimetypeUtils {
    35      /***
    36       * The 'no-type' content-type.
    37       *
    38       * Defined in the ARC file spec at
    39       * http://www.archive.org/web/researcher/ArcFileFormat.php.
    40       */
    41      public static final String NO_TYPE_MIMETYPE = "no-type";
    42
    43      /***
    44       * Truncation regex.
    45       */
    46      final static Pattern TRUNCATION_REGEX = Pattern.compile("^([^//s;,]+).*");
    47
    48
    49      /***
    50       * Truncate passed mimetype.
    51       *
    52       * Ensure no spaces.  Strip encoding.  Truncation required by
    53       * ARC files.
    54       *
    55       * <p>Truncate at delimiters [;, ].
    56       * Truncate multi-part content type header at ';'.
    57       * Apache httpclient collapses values of multiple instances of the
    58       * header into one comma-separated value,therefore truncated at ','.
    59       * Current ia_tools that work with arc files expect 5-column
    60       * space-separated meta-lines, therefore truncate at ' '.
    61       *
    62       * @param contentType Raw content-type.
    63       *
    64       * @return Computed content-type made from passed content-type after
    65       * running it through a set of rules.
    66       */
    67      public static String truncate(String contentType) {
    68          if (contentType == null) {
    69              contentType = NO_TYPE_MIMETYPE;
    70          } else {
    71              Matcher matcher = TRUNCATION_REGEX.matcher(contentType);
    72              if (matcher.matches()) {
    73              	contentType = matcher.group(1);
    74              } else {
    75              	contentType = NO_TYPE_MIMETYPE;
    76              }
    77          }
    78
    79          return contentType;
    80      }
    81  }