    1   /* AcceptDecideRule
    2   *
    3   * $Id: PrerequisiteAcceptDecideRule.java 4649 2006-09-25 17:16:55Z paul_jack $
    4   *
    5   * Created on Mar 3, 2005
    6   *
    7   * Copyright (C) 2005 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.crawler.deciderules;
    26
    27  import org.archive.crawler.datamodel.CandidateURI;
    28  import org.archive.crawler.extractor.Link;
    29
    30
    31  /***
    32   * Rule which ACCEPTs all 'prerequisite' URIs (those with a 'P' in
    33   * the last hopsPath position). Good in a late position to ensure
    34   * other scope settings don't lock out necessary prerequisites.
    35   *
    36   * @author gojomo
    37   */
    38  public class PrerequisiteAcceptDecideRule extends AcceptDecideRule {
    39
    40      private static final long serialVersionUID = 2762042167111186142L;
    41
    42      public PrerequisiteAcceptDecideRule(String name) {
    43          super(name);
    44          setDescription("PrerequisiteAcceptDecideRule. ACCEPTs " +
    45                  "all CrawlURIs discovered via a prerequisite " +
    46                  "'link'.");
    47      }
    48
    49      public Object decisionFor(Object object) {
    50          try {
    51              String hopsPath = ((CandidateURI)object).getPathFromSeed();
    52              if (hopsPath != null && hopsPath.length() > 0 &&
    53                      hopsPath.charAt(hopsPath.length()-1) == Link.PREREQ_HOP) {
    54                  return ACCEPT;
    55              }
    56          } catch (ClassCastException e) {
    57             // Do nothing
    58          }
    59          return PASS;
    60      }
    61  }