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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><meta http-equiv="content-type" content="text/html; charset=UTF-8" /><title>TransclusionDecideRule xref</title><link type="text/css" rel="stylesheet" href="../../../../stylesheet.css" /></head><body><div id="overview"><a href="../../../../../apidocs/org/archive/crawler/deciderules/TransclusionDecideRule.html">View Javadoc</a></div><pre><a name="1" href="#1">1</a> <em class="comment">/*<em class="comment"> TransclusionDecideRule</em></em><a name="2" href="#2">2</a> <em class="comment">*</em><a name="3" href="#3">3</a> <em class="comment">* $Id: TransclusionDecideRule.java,v 1.4 2005/04/14 21:48:27 stack-sf Exp $</em><a name="4" href="#4">4</a> <em class="comment">*</em><a name="5" href="#5">5</a> <em class="comment">* Created on Apr 1, 2005</em><a name="6" href="#6">6</a> <em class="comment">*</em><a name="7" href="#7">7</a> <em class="comment">* Copyright (C) 2005 Internet Archive.</em><a name="8" href="#8">8</a> <em class="comment">*</em><a name="9" href="#9">9</a> <em class="comment">* This file is part of the Heritrix web crawler (crawler.archive.org).</em><a name="10" href="#10">10</a> <em class="comment">*</em><a name="11" href="#11">11</a> <em class="comment">* Heritrix is free software; you can redistribute it and/or modify</em><a name="12" href="#12">12</a> <em class="comment">* it under the terms of the GNU Lesser Public License as published by</em><a name="13" href="#13">13</a> <em class="comment">* the Free Software Foundation; either version 2.1 of the License, or</em><a name="14" href="#14">14</a> <em class="comment">* any later version.</em><a name="15" href="#15">15</a> <em class="comment">*</em><a name="16" href="#16">16</a> <em class="comment">* Heritrix is distributed in the hope that it will be useful,</em><a name="17" href="#17">17</a> <em class="comment">* but WITHOUT ANY WARRANTY; without even the implied warranty of</em><a name="18" href="#18">18</a> <em class="comment">* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the</em><a name="19" href="#19">19</a> <em class="comment">* GNU Lesser Public License for more details.</em><a name="20" href="#20">20</a> <em class="comment">*</em><a name="21" href="#21">21</a> <em class="comment">* You should have received a copy of the GNU Lesser Public License</em><a name="22" href="#22">22</a> <em class="comment">* along with Heritrix; if not, write to the Free Software</em><a name="23" href="#23">23</a> <em class="comment">* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA</em><a name="24" href="#24">24</a> <em class="comment">*/</em><a name="25" href="#25">25</a> <strong>package</strong> <a href="../../../../org/archive/crawler/deciderules/package-summary.html">org.archive.crawler.deciderules</a>;<a name="26" href="#26">26</a> <a name="27" href="#27">27</a> <strong>import</strong> org.archive.crawler.datamodel.CandidateURI;<a name="28" href="#28">28</a> <strong>import</strong> org.archive.crawler.extractor.Link;<a name="29" href="#29">29</a> <strong>import</strong> org.archive.crawler.settings.SimpleType;<a name="30" href="#30">30</a> <strong>import</strong> org.archive.crawler.settings.Type;<a name="31" href="#31">31</a> <a name="32" href="#32">32</a> <a name="33" href="#33">33</a> <a name="34" href="#34">34</a> <em>/**<em>*</em></em><a name="35" href="#35">35</a> <em> * Rule ACCEPTs any CrawlURIs whose path-from-seed ('hopsPath' -- see</em><a name="36" href="#36">36</a> <em> * {@link CandidateURI#getPathFromSeed()}) ends </em><a name="37" href="#37">37</a> <em> * with at least one, but not more than, the given number of </em><a name="38" href="#38">38</a> <em> * non-navlink ('L') hops. </em><a name="39" href="#39">39</a> <em> * </em><a name="40" href="#40">40</a> <em> * Otherwise, if the path-from-seed is empty or if a navlink ('L') occurs</em><a name="41" href="#41">41</a> <em> * within max-trans-hops of the tail of the path-from-seed, this rule</em><a name="42" href="#42">42</a> <em> * returns PASS.</em><a name="43" href="#43">43</a> <em> * </em><a name="44" href="#44">44</a> <em> * <p>Thus, it allows things like embedded resources (frames/images/media) </em><a name="45" href="#45">45</a> <em> * and redirects to be transitively included ('transcluded') in a crawl, </em><a name="46" href="#46">46</a> <em> * even if they otherwise would not, for some reasonable number of hops</em><a name="47" href="#47">47</a> <em> * (1-4).</em><a name="48" href="#48">48</a> <em> *</em><a name="49" href="#49">49</a> <em> * @see <a href="<a href="http://www.google.com/search?q=define%3Atransclusion&sourceid=mozilla&start=0&start=0&ie=utf-8&oe=utf-8" target="alexandria_uri">http://www.google.com/search?q=define%3Atransclusion&sourceid=mozilla&start=0&start=0&ie=utf-8&oe=utf-8</a>">Transclusion</a></em><a name="50" href="#50">50</a> <em> *</em><a name="51" href="#51">51</a> <em> * @author gojomo</em><a name="52" href="#52">52</a> <em> */</em><a name="53" href="#53">53</a> <strong>public</strong> <strong>class</strong> <a href="../../../../org/archive/crawler/deciderules/TransclusionDecideRule.html">TransclusionDecideRule</a> <strong>extends</strong> <a href="../../../../org/archive/crawler/deciderules/PredicatedDecideRule.html">PredicatedDecideRule</a> {<a name="54" href="#54">54</a> <strong>private</strong> <strong>static</strong> <strong>final</strong> String ATTR_MAX_TRANS_HOPS = <span class="string">"max-trans-hops"</span>;<a name="55" href="#55">55</a> <a name="56" href="#56">56</a> <em>/**<em>*</em></em><a name="57" href="#57">57</a> <em> * Default maximum hops.</em><a name="58" href="#58">58</a> <em> * Default access so can be accessed by unit tests.</em><a name="59" href="#59">59</a> <em> */</em><a name="60" href="#60">60</a> <strong>static</strong> <strong>final</strong> Integer DEFAULT_MAX_TRANS_HOPS = <strong>new</strong> Integer(3);<a name="61" href="#61">61</a> <a name="62" href="#62">62</a> <em>/**<em>*</em></em><a name="63" href="#63">63</a> <em> * Usual constructor. </em><a name="64" href="#64">64</a> <em> * @param name Name of this DecideRule.</em><a name="65" href="#65">65</a> <em> */</em><a name="66" href="#66">66</a> <strong>public</strong> <a href="../../../../org/archive/crawler/deciderules/TransclusionDecideRule.html">TransclusionDecideRule</a>(String name) {<a name="67" href="#67">67</a> <strong>super</strong>(name);<a name="68" href="#68">68</a> setDescription(<span class="string">"TransclusionDecideRule. ACCEPTs URIs whose path "</span> +<a name="69" href="#69">69</a> <span class="string">"from the seed ends with up to (but not more than) the "</span> +<a name="70" href="#70">70</a> <span class="string">"configured '"</span> + ATTR_MAX_TRANS_HOPS +<a name="71" href="#71">71</a> <span class="string">"' number of non-navlink ('L') hops."</span>);<a name="72" href="#72">72</a> <em class="comment">// make default ACCEPT unchangeable </em><a name="73" href="#73">73</a> <a href="../../../../org/archive/crawler/settings/Type.html">Type</a> type = getElementFromDefinition(ATTR_DECISION);<a name="74" href="#74">74</a> type.setTransient(<strong>true</strong>);<a name="75" href="#75">75</a> addElementToDefinition(<strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_MAX_TRANS_HOPS,<a name="76" href="#76">76</a> <span class="string">"Maximum number of non-navlink ('L') hops."</span>, <a name="77" href="#77">77</a> DEFAULT_MAX_TRANS_HOPS));<a name="78" href="#78">78</a> <em class="comment">// TODO: add expert settings for further penalizing certain hop types,</em><a name="79" href="#79">79</a> <em class="comment">// eg: make speculative hops ('X') count 3x, etc.</em><a name="80" href="#80">80</a> }<a name="81" href="#81">81</a> <a name="82" href="#82">82</a> <em>/**<em>*</em></em><a name="83" href="#83">83</a> <em> * Evaluate whether given object is within the threshold number of</em><a name="84" href="#84">84</a> <em> * transitive hops.</em><a name="85" href="#85">85</a> <em> * </em><a name="86" href="#86">86</a> <em> * @param object Object to make decision on.</em><a name="87" href="#87">87</a> <em> * @return true if the transitive hops >0 and <= max</em><a name="88" href="#88">88</a> <em> */</em><a name="89" href="#89">89</a> <strong>protected</strong> <strong>boolean</strong> evaluate(Object object) {<a name="90" href="#90">90</a> <a href="../../../../org/archive/crawler/datamodel/CandidateURI.html">CandidateURI</a> curi = <strong>null</strong>;<a name="91" href="#91">91</a> <strong>try</strong> {<a name="92" href="#92">92</a> curi = (CandidateURI)object;<a name="93" href="#93">93</a> } <strong>catch</strong> (ClassCastException e) {<a name="94" href="#94">94</a> <em class="comment">// if not CrawlURI, always disregard.</em><a name="95" href="#95">95</a> <strong>return</strong> false;<a name="96" href="#96">96</a> }<a name="97" href="#97">97</a> String hopsPath = curi.getPathFromSeed();<a name="98" href="#98">98</a> <strong>if</strong> (hopsPath == <strong>null</strong> || hopsPath.length() == 0) {<a name="99" href="#99">99</a> <strong>return</strong> false; <a name="100" href="#100">100</a> }<a name="101" href="#101">101</a> <strong>int</strong> count = 0;<a name="102" href="#102">102</a> <strong>for</strong> (<strong>int</strong> i = hopsPath.length() - 1; i >= 0; i--) {<a name="103" href="#103">103</a> <strong>if</strong> (hopsPath.charAt(i) != Link.NAVLINK_HOP) {<a name="104" href="#104">104</a> <em class="comment">// TODO: count some hops for more (to bias against chains </em><a name="105" href="#105">105</a> <em class="comment">// of them, eg 'X' speculative links that might really be</em><a name="106" href="#106">106</a> <em class="comment">// navlinks)</em><a name="107" href="#107">107</a> count++;<a name="108" href="#108">108</a> } <strong>else</strong> {<a name="109" href="#109">109</a> <strong>break</strong>;<a name="110" href="#110">110</a> }<a name="111" href="#111">111</a> }<a name="112" href="#112">112</a> <strong>return</strong> count > 0 && count <= getThresholdHops(object);<a name="113" href="#113">113</a> }<a name="114" href="#114">114</a> <a name="115" href="#115">115</a> <em>/**<em>*</em></em><a name="116" href="#116">116</a> <em> * @param obj Context object.</em><a name="117" href="#117">117</a> <em> * @return hops cutoff threshold</em><a name="118" href="#118">118</a> <em> */</em><a name="119" href="#119">119</a> <strong>private</strong> <strong>int</strong> getThresholdHops(Object obj) {<a name="120" href="#120">120</a> <strong>return</strong> ((Integer)getUncheckedAttribute(obj,ATTR_MAX_TRANS_HOPS)).<a name="121" href="#121">121</a> intValue();<a name="122" href="#122">122</a> }<a name="123" href="#123">123</a> }</pre><hr/><div id="footer">This page was automatically generated by <a href="http://maven.apache.org/">Maven</a></div></body></html>⌨️ 快捷键说明
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