📄 filter.html
字号:
<!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>Filter xref</title><link type="text/css" rel="stylesheet" href="../../../../stylesheet.css" /></head><body><div id="overview"><a href="../../../../../apidocs/org/archive/crawler/framework/Filter.html">View Javadoc</a></div><pre><a name="1" href="#1">1</a> <em class="comment">/*<em class="comment"> Copyright (C) 2003 Internet Archive.</em></em><a name="2" href="#2">2</a> <em class="comment"> *</em><a name="3" href="#3">3</a> <em class="comment"> * This file is part of the Heritrix web crawler (crawler.archive.org).</em><a name="4" href="#4">4</a> <em class="comment"> *</em><a name="5" href="#5">5</a> <em class="comment"> * Heritrix is free software; you can redistribute it and/or modify</em><a name="6" href="#6">6</a> <em class="comment"> * it under the terms of the GNU Lesser Public License as published by</em><a name="7" href="#7">7</a> <em class="comment"> * the Free Software Foundation; either version 2.1 of the License, or</em><a name="8" href="#8">8</a> <em class="comment"> * any later version.</em><a name="9" href="#9">9</a> <em class="comment"> *</em><a name="10" href="#10">10</a> <em class="comment"> * Heritrix is distributed in the hope that it will be useful,</em><a name="11" href="#11">11</a> <em class="comment"> * but WITHOUT ANY WARRANTY; without even the implied warranty of</em><a name="12" href="#12">12</a> <em class="comment"> * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the</em><a name="13" href="#13">13</a> <em class="comment"> * GNU Lesser Public License for more details.</em><a name="14" href="#14">14</a> <em class="comment"> *</em><a name="15" href="#15">15</a> <em class="comment"> * You should have received a copy of the GNU Lesser Public License</em><a name="16" href="#16">16</a> <em class="comment"> * along with Heritrix; if not, write to the Free Software</em><a name="17" href="#17">17</a> <em class="comment"> * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA</em><a name="18" href="#18">18</a> <em class="comment"> *</em><a name="19" href="#19">19</a> <em class="comment"> * Filter.java</em><a name="20" href="#20">20</a> <em class="comment"> * Created on Apr 16, 2003</em><a name="21" href="#21">21</a> <em class="comment"> *</em><a name="22" href="#22">22</a> <em class="comment"> * $Header: /cvsroot/archive-crawler/ArchiveOpenCrawler/src/java/org/archive/crawler/framework/Filter.java,v 1.21 2005/04/05 20:27:14 stack-sf Exp $</em><a name="23" href="#23">23</a> <em class="comment"> */</em><a name="24" href="#24">24</a> <strong>package</strong> <a href="../../../../org/archive/crawler/framework/package-summary.html">org.archive.crawler.framework</a>;<a name="25" href="#25">25</a> <a name="26" href="#26">26</a> <strong>import</strong> java.util.logging.Level;<a name="27" href="#27">27</a> <strong>import</strong> java.util.logging.Logger;<a name="28" href="#28">28</a> <a name="29" href="#29">29</a> <strong>import</strong> javax.management.AttributeNotFoundException;<a name="30" href="#30">30</a> <a name="31" href="#31">31</a> <strong>import</strong> org.archive.crawler.datamodel.CrawlURI;<a name="32" href="#32">32</a> <strong>import</strong> org.archive.crawler.settings.ComplexType;<a name="33" href="#33">33</a> <strong>import</strong> org.archive.crawler.settings.MapType;<a name="34" href="#34">34</a> <strong>import</strong> org.archive.crawler.settings.ModuleType;<a name="35" href="#35">35</a> <strong>import</strong> org.archive.crawler.settings.SimpleType;<a name="36" href="#36">36</a> <a name="37" href="#37">37</a> <em>/**<em>*</em></em><a name="38" href="#38">38</a> <em> * Base class for filter classes.</em><a name="39" href="#39">39</a> <em> * <p></em><a name="40" href="#40">40</a> <em> * Several classes allow 'filters' to be applied to them. Filters are classes</em><a name="41" href="#41">41</a> <em> * that, based on an arbitrary object passed to them, return a boolean stating</em><a name="42" href="#42">42</a> <em> * if if passes the filter. Thus applying filters can affect the behavior of</em><a name="43" href="#43">43</a> <em> * those classes. This class provides the basic framework for filters. All</em><a name="44" href="#44">44</a> <em> * detailed implementation of filters inherit from it and it is considered to</em><a name="45" href="#45">45</a> <em> * be a 'null' filter (always returns true).</em><a name="46" href="#46">46</a> <em> *</em><a name="47" href="#47">47</a> <em> * @author Gordon Mohr</em><a name="48" href="#48">48</a> <em> *</em><a name="49" href="#49">49</a> <em> * @see org.archive.crawler.framework.Processor</em><a name="50" href="#50">50</a> <em> */</em><a name="51" href="#51">51</a> <strong>public</strong> <strong>class</strong> <a href="../../../../org/archive/crawler/framework/Filter.html">Filter</a> <strong>extends</strong> <a href="../../../../org/archive/crawler/settings/ModuleType.html">ModuleType</a> {<a name="52" href="#52">52</a> <strong>private</strong> <strong>static</strong> Logger logger =<a name="53" href="#53">53</a> Logger.getLogger(<span class="string">"org.archive.crawler.framework.Filter"</span>);<a name="54" href="#54">54</a> <a name="55" href="#55">55</a> <strong>public</strong> <strong>static</strong> <strong>final</strong> String ATTR_ENABLED = <span class="string">"enabled"</span>;<a name="56" href="#56">56</a> <a name="57" href="#57">57</a> <em>/**<em>*</em></em><a name="58" href="#58">58</a> <em> * Creates a new 'null' filter.</em><a name="59" href="#59">59</a> <em> * @param name the name of the filter.</em><a name="60" href="#60">60</a> <em> * @param description an description of the filter suitable for showing in</em><a name="61" href="#61">61</a> <em> * the user interface.</em><a name="62" href="#62">62</a> <em> */</em><a name="63" href="#63">63</a> <strong>public</strong> <a href="../../../../org/archive/crawler/framework/Filter.html">Filter</a>(String name, String description) {<a name="64" href="#64">64</a> <strong>super</strong>(name, description);<a name="65" href="#65">65</a> addElementToDefinition(<a name="66" href="#66">66</a> <strong>new</strong> <a href="../../../../org/archive/crawler/settings/SimpleType.html">SimpleType</a>(ATTR_ENABLED,<a name="67" href="#67">67</a> <span class="string">"Filter is enabled."</span>, <strong>new</strong> Boolean(<strong>true</strong>)));<a name="68" href="#68">68</a> }<a name="69" href="#69">69</a> <a name="70" href="#70">70</a> <em>/**<em>*</em></em><a name="71" href="#71">71</a> <em> * Creates a new 'null' filter.</em><a name="72" href="#72">72</a> <em> * @param name the name of the filter.</em><a name="73" href="#73">73</a> <em> */</em><a name="74" href="#74">74</a> <strong>public</strong> <a href="../../../../org/archive/crawler/framework/Filter.html">Filter</a>(String name) {<a name="75" href="#75">75</a> <strong>this</strong>(name, <span class="string">"Null filter - accepts everything."</span>);<a name="76" href="#76">76</a> }<a name="77" href="#77">77</a> <a name="78" href="#78">78</a> <strong>public</strong> <strong>boolean</strong> accepts(Object o) {<a name="79" href="#79">79</a> <a href="../../../../org/archive/crawler/datamodel/CrawlURI.html">CrawlURI</a> curi = (o instanceof CrawlURI) ? (CrawlURI) o : <strong>null</strong>;<a name="80" href="#80">80</a> <a name="81" href="#81">81</a> <em class="comment">// Skip the evaluation if the filter is disabled</em><a name="82" href="#82">82</a> <strong>try</strong> {<a name="83" href="#83">83</a> <strong>if</strong> (!((Boolean)getAttribute(ATTR_ENABLED, curi)).booleanValue()) {<a name="84" href="#84">84</a> <strong>return</strong> getFilterOffPosition(curi);<a name="85" href="#85">85</a> }<a name="86" href="#86">86</a> } <strong>catch</strong> (AttributeNotFoundException e) {<a name="87" href="#87">87</a> logger.severe(e.getMessage());<a name="88" href="#88">88</a> }<a name="89" href="#89">89</a> <a name="90" href="#90">90</a> <strong>boolean</strong> accept = returnTrueIfMatches(curi) == innerAccepts(o);<a name="91" href="#91">91</a> <strong>if</strong> (accept && logger.isLoggable(Level.FINEST)) {<a name="92" href="#92">92</a> <em class="comment">// Log if filter returns true</em><a name="93" href="#93">93</a> <a href="../../../../org/archive/crawler/settings/ComplexType.html">ComplexType</a> p = <strong>this</strong>.getParent();<a name="94" href="#94">94</a> <strong>if</strong> (p instanceof MapType) {<a name="95" href="#95">95</a> p = p.getParent();<a name="96" href="#96">96</a> }<a name="97" href="#97">97</a> String msg = <strong>this</strong>.toString() + <span class="string">" belonging to "</span> + p.toString()<a name="98" href="#98">98</a> + <span class="string">" accepted "</span> + o.toString();<a name="99" href="#99">99</a> logger.finest(msg);<a name="100" href="#100">100</a> }<a name="101" href="#101">101</a> <strong>return</strong> accept;<a name="102" href="#102">102</a> }<a name="103" href="#103">103</a> <a name="104" href="#104">104</a> <em>/**<em>*</em></em><a name="105" href="#105">105</a> <em> * If the filter is disabled, the value returned by this method is</em><a name="106" href="#106">106</a> <em> * what filters return as their disabled setting.</em><a name="107" href="#107">107</a> <em> * Default is that we return 'true', continue processing, but some</em><a name="108" href="#108">108</a> <em> * filters -- the exclude filters for example -- will want to return</em><a name="109" href="#109">109</a> <em> * false if disabled so processing can continue.</em><a name="110" href="#110">110</a> <em> * @param curi CrawlURI to use as context. Passed curi can be null.</em><a name="111" href="#111">111</a> <em> * @return This filters 'off' position.</em><a name="112" href="#112">112</a> <em> */</em><a name="113" href="#113">113</a> <strong>protected</strong> <strong>boolean</strong> getFilterOffPosition(<a href="../../../../org/archive/crawler/datamodel/CrawlURI.html">CrawlURI</a> curi) {<a name="114" href="#114">114</a> <strong>return</strong> <strong>true</strong>;<a name="115" href="#115">115</a> }<a name="116" href="#116">116</a> <a name="117" href="#117">117</a> <em>/**<em>*</em></em><a name="118" href="#118">118</a> <em> * Checks to see if filter functionality should be inverted for this</em><a name="119" href="#119">119</a> <em> * curi.<p></em><a name="120" href="#120">120</a> <em> *</em><a name="121" href="#121">121</a> <em> * All filters will by default return true if curi is accepted by the</em><a name="122" href="#122">122</a> <em> * filter. If this method returns false, then the filter will return true</em><a name="123" href="#123">123</a> <em> * if doesn't match.<p></em><a name="124" href="#124">124</a> <em> *</em><a name="125" href="#125">125</a> <em> * Classes extending this class should override this method with</em><a name="126" href="#126">126</a> <em> * appropriate code.</em><a name="127" href="#127">127</a> <em> *</em><a name="128" href="#128">128</a> <em> * @param curi Current CrawlURI</em><a name="129" href="#129">129</a> <em> * @return true for default behaviour, false otherwise.</em><a name="130" href="#130">130</a> <em> */</em><a name="131" href="#131">131</a> <strong>protected</strong> <strong>boolean</strong> returnTrueIfMatches(<a href="../../../../org/archive/crawler/datamodel/CrawlURI.html">CrawlURI</a> curi){<a name="132" href="#132">132</a> <strong>return</strong> <strong>true</strong>;<a name="133" href="#133">133</a> }<a name="134" href="#134">134</a> <a name="135" href="#135">135</a> <em>/**<em>*</em></em><a name="136" href="#136">136</a> <em> * Classes subclassing this one should override this method to perfrom</em><a name="137" href="#137">137</a> <em> * their custom determination of whether or not the object given to it.</em><a name="138" href="#138">138</a> <em> *</em><a name="139" href="#139">139</a> <em> * @param o The object</em><a name="140" href="#140">140</a> <em> * @return True if it passes the filter.</em><a name="141" href="#141">141</a> <em> */</em><a name="142" href="#142">142</a> <strong>protected</strong> <strong>boolean</strong> innerAccepts(Object o) {<a name="143" href="#143">143</a> <strong>return</strong> <strong>true</strong>;<a name="144" href="#144">144</a> }<a name="145" href="#145">145</a> <a name="146" href="#146">146</a> <strong>public</strong> String toString() {<a name="147" href="#147">147</a> <strong>return</strong> <span class="string">"Filter<"</span> + getName() + <span class="string">">"</span>;<a name="148" href="#148">148</a> }<a name="149" href="#149">149</a> <a name="150" href="#150">150</a> <strong>public</strong> <strong>void</strong> kickUpdate() {<a name="151" href="#151">151</a> <em class="comment">// by default, do nothing</em><a name="152" href="#152">152</a> }<a name="153" href="#153">153</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
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -