    1   /*
    2    * Created on 2006-aug-25
    3    *
    4    * Copyright (C) 2006 Royal Library of Sweden.
    5    *
    6    * This program is free software; you can redistribute it and/or
    7    * modify it under the terms of the GNU Lesser General Public License
    8    * as published by the Free Software Foundation; either version 2
    9    * of the License, or (at your option) any later version.
    10   *
    11   * This program is distributed in the hope that it will be useful,
    12   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    13   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    14   * GNU Lesser General Public License for more details.
    15   *
    16   * You should have received a copy of the GNU Lesser General Public License
    17   * along with this program; if not, write to the Free Software
    18   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
    19   */
    20  package org.archive.crawler.url.canonicalize;
    21
    22  import java.util.regex.Matcher;
    23  import java.util.regex.Pattern;
    24
    25  public class StripExtraSlashes extends BaseRule {
    26
    27      private static final String DESCRIPTION =
    28          "Strip any extra slashes, '/', found in the path. " +
    29          "Use this rule to equate 'http://www.archive.org//A//B/index.html' and " +
    30          "'http://www.archive.org/A/B/index.html'.";
    31
    32      private static final Pattern REGEX = Pattern.compile("(^https?://.*?)//+(.*)");
    33
    34      public StripExtraSlashes(String name) {
    35          super(name, DESCRIPTION);
    36      }
    37
    38      public String canonicalize(String url, Object context) {
    39          Matcher matcher = REGEX.matcher(url);
    40          while (matcher.matches()) {
    41              url = matcher.group(1) + "/" + matcher.group(2);
    42              matcher = REGEX.matcher(url);
    43          }
    44          return url;
    45      }
    46  }