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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>ArchiveReader xref</title><link type="text/css" rel="stylesheet" href="../../../stylesheet.css" /></head><body><div id="overview"><a href="../../../../apidocs/org/archive/io/ArchiveReader.html">View Javadoc</a></div><pre><a name="1" href="#1">1</a> <em class="comment">/*<em class="comment"> $Id: ArchiveReader.java,v 1.5 2006/08/31 16:51:41 stack-sf Exp $</em></em><a name="2" href="#2">2</a> <em class="comment"> *</em><a name="3" href="#3">3</a> <em class="comment"> * Created on August 21st, 2006</em><a name="4" href="#4">4</a> <em class="comment"> *</em><a name="5" href="#5">5</a> <em class="comment"> * Copyright (C) 2006 Internet Archive.</em><a name="6" href="#6">6</a> <em class="comment"> *</em><a name="7" href="#7">7</a> <em class="comment"> * This file is part of the Heritrix web crawler (crawler.archive.org).</em><a name="8" href="#8">8</a> <em class="comment"> *</em><a name="9" href="#9">9</a> <em class="comment"> * Heritrix is free software; you can redistribute it and/or modify</em><a name="10" href="#10">10</a> <em class="comment"> * it under the terms of the GNU Lesser Public License as published by</em><a name="11" href="#11">11</a> <em class="comment"> * the Free Software Foundation; either version 2.1 of the License, or</em><a name="12" href="#12">12</a> <em class="comment"> * any later version.</em><a name="13" href="#13">13</a> <em class="comment"> *</em><a name="14" href="#14">14</a> <em class="comment"> * Heritrix is distributed in the hope that it will be useful,</em><a name="15" href="#15">15</a> <em class="comment"> * but WITHOUT ANY WARRANTY; without even the implied warranty of</em><a name="16" href="#16">16</a> <em class="comment"> * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the</em><a name="17" href="#17">17</a> <em class="comment"> * GNU Lesser Public License for more details.</em><a name="18" href="#18">18</a> <em class="comment"> *</em><a name="19" href="#19">19</a> <em class="comment"> * You should have received a copy of the GNU Lesser Public License</em><a name="20" href="#20">20</a> <em class="comment"> * along with Heritrix; if not, write to the Free Software</em><a name="21" href="#21">21</a> <em class="comment"> * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA</em><a name="22" href="#22">22</a> <em class="comment"> */</em><a name="23" href="#23">23</a> <strong>package</strong> <a href="../../../org/archive/io/package-summary.html">org.archive.io</a>;<a name="24" href="#24">24</a> <a name="25" href="#25">25</a> <strong>import</strong> it.unimi.dsi.fastutil.io.RepositionableStream;<a name="26" href="#26">26</a> <a name="27" href="#27">27</a> <strong>import</strong> java.io.BufferedInputStream;<a name="28" href="#28">28</a> <strong>import</strong> java.io.BufferedWriter;<a name="29" href="#29">29</a> <strong>import</strong> java.io.File;<a name="30" href="#30">30</a> <strong>import</strong> java.io.FileWriter;<a name="31" href="#31">31</a> <strong>import</strong> java.io.IOException;<a name="32" href="#32">32</a> <strong>import</strong> java.io.InputStream;<a name="33" href="#33">33</a> <strong>import</strong> java.util.ArrayList;<a name="34" href="#34">34</a> <strong>import</strong> java.util.Iterator;<a name="35" href="#35">35</a> <strong>import</strong> java.util.List;<a name="36" href="#36">36</a> <strong>import</strong> java.util.logging.Level;<a name="37" href="#37">37</a> <strong>import</strong> java.util.logging.Logger;<a name="38" href="#38">38</a> <a name="39" href="#39">39</a> <strong>import</strong> org.archive.util.MimetypeUtils;<a name="40" href="#40">40</a> <a name="41" href="#41">41</a> <a name="42" href="#42">42</a> <em>/**<em>*</em></em><a name="43" href="#43">43</a> <em> * Reader for an Archive file of Archive {@link ArchiveRecord}s.</em><a name="44" href="#44">44</a> <em> * @author stack</em><a name="45" href="#45">45</a> <em> * @version $Date: 2006/08/31 16:51:41 $ $Version$</em><a name="46" href="#46">46</a> <em> */</em><a name="47" href="#47">47</a> <strong>public</strong> <strong>abstract</strong> <strong>class</strong> <a href="../../../org/archive/io/ArchiveReader.html">ArchiveReader</a> implements <a href="../../../org/archive/io/ArchiveFileConstants.html">ArchiveFileConstants</a> { <a name="48" href="#48">48</a> <em>/**<em>*</em></em><a name="49" href="#49">49</a> <em> * Is this Archive file compressed?</em><a name="50" href="#50">50</a> <em> */</em><a name="51" href="#51">51</a> <strong>private</strong> <strong>boolean</strong> compressed = false;<a name="52" href="#52">52</a> <a name="53" href="#53">53</a> <em>/**<em>*</em></em><a name="54" href="#54">54</a> <em> * Should we digest as we read?</em><a name="55" href="#55">55</a> <em> */</em><a name="56" href="#56">56</a> <strong>private</strong> <strong>boolean</strong> digest = <strong>true</strong>;<a name="57" href="#57">57</a> <a name="58" href="#58">58</a> <em>/**<em>*</em></em><a name="59" href="#59">59</a> <em> * Should the parse be strict?</em><a name="60" href="#60">60</a> <em> */</em><a name="61" href="#61">61</a> <strong>private</strong> <strong>boolean</strong> strict = false;<a name="62" href="#62">62</a> <a name="63" href="#63">63</a> <em>/**<em>*</em></em><a name="64" href="#64">64</a> <em> * Archive file input stream.</em><a name="65" href="#65">65</a> <em> *</em><a name="66" href="#66">66</a> <em> * Keep it around so we can close it when done.</em><a name="67" href="#67">67</a> <em> *</em><a name="68" href="#68">68</a> <em> * <p>Set in constructor. Must support {@link RepositionableStream}</em><a name="69" href="#69">69</a> <em> * interface. Make it protected so subclasses have access.</em><a name="70" href="#70">70</a> <em> */</em><a name="71" href="#71">71</a> <strong>private</strong> InputStream in = <strong>null</strong>;<a name="72" href="#72">72</a> <a name="73" href="#73">73</a> <em>/**<em>*</em></em><a name="74" href="#74">74</a> <em> * Maximum amount of recoverable exceptions in a row.</em><a name="75" href="#75">75</a> <em> * If more than this amount in a row, we'll let out the exception rather</em><a name="76" href="#76">76</a> <em> * than go back in for yet another retry.</em><a name="77" href="#77">77</a> <em> */</em><a name="78" href="#78">78</a> <strong>public</strong> <strong>static</strong> <strong>final</strong> <strong>int</strong> MAX_ALLOWED_RECOVERABLES = 10;<a name="79" href="#79">79</a> <a name="80" href="#80">80</a> <a name="81" href="#81">81</a> <em>/**<em>*</em></em><a name="82" href="#82">82</a> <em> * The Record currently being read.</em><a name="83" href="#83">83</a> <em> *</em><a name="84" href="#84">84</a> <em> * Keep this ongoing reference so we'll close the record even if the caller</em><a name="85" href="#85">85</a> <em> * doesn't.</em><a name="86" href="#86">86</a> <em> */</em><a name="87" href="#87">87</a> <strong>private</strong> <a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> currentRecord = <strong>null</strong>;<a name="88" href="#88">88</a> <a name="89" href="#89">89</a> <em>/**<em>*</em></em><a name="90" href="#90">90</a> <em> * Descriptive string for the Archive file we're going against:</em><a name="91" href="#91">91</a> <em> * full path, url, etc. -- depends on context in which file was made.</em><a name="92" href="#92">92</a> <em> */</em><a name="93" href="#93">93</a> <strong>private</strong> String identifier = <strong>null</strong>;<a name="94" href="#94">94</a> <a name="95" href="#95">95</a> <em>/**<em>*</em></em><a name="96" href="#96">96</a> <em> * Archive file version.</em><a name="97" href="#97">97</a> <em> */</em><a name="98" href="#98">98</a> <strong>private</strong> String version = <strong>null</strong>;<a name="99" href="#99">99</a> <a name="100" href="#100">100</a> <a name="101" href="#101">101</a> <strong>protected</strong> <a href="../../../org/archive/io/ArchiveReader.html">ArchiveReader</a>() {<a name="102" href="#102">102</a> <strong>super</strong>();<a name="103" href="#103">103</a> }<a name="104" href="#104">104</a> <a name="105" href="#105">105</a> <em>/**<em>*</em></em><a name="106" href="#106">106</a> <em> * Convenience method used by subclass constructors.</em><a name="107" href="#107">107</a> <em> * @param i Identifier for Archive file this reader goes against.</em><a name="108" href="#108">108</a> <em> */</em><a name="109" href="#109">109</a> <strong>protected</strong> <strong>void</strong> initialize(<strong>final</strong> String i) {<a name="110" href="#110">110</a> setReaderIdentifier(i);<a name="111" href="#111">111</a> }<a name="112" href="#112">112</a> <a name="113" href="#113">113</a> <em>/**<em>*</em></em><a name="114" href="#114">114</a> <em> * Convenience method for constructors.</em><a name="115" href="#115">115</a> <em> * </em><a name="116" href="#116">116</a> <em> * @param f File to read.</em><a name="117" href="#117">117</a> <em> * @param offset Offset at which to start reading.</em><a name="118" href="#118">118</a> <em> * @return InputStream to read from.</em><a name="119" href="#119">119</a> <em> * @throws IOException If failed open or fail to get a memory</em><a name="120" href="#120">120</a> <em> * mapped byte buffer on file.</em><a name="121" href="#121">121</a> <em> */</em><a name="122" href="#122">122</a> <strong>protected</strong> InputStream getInputStream(<strong>final</strong> File f, <strong>final</strong> <strong>long</strong> offset)<a name="123" href="#123">123</a> throws IOException {<a name="124" href="#124">124</a> <strong>return</strong> <strong>new</strong> RepositionableBufferedInputStream(<a name="125" href="#125">125</a> <strong>new</strong> <a href="../../../org/archive/io/RandomAccessInputStream.html">RandomAccessInputStream</a>(f, offset));<a name="126" href="#126">126</a> }<a name="127" href="#127">127</a> <a name="128" href="#128">128</a> <strong>public</strong> <strong>boolean</strong> isCompressed() {<a name="129" href="#129">129</a> <strong>return</strong> <strong>this</strong>.compressed;<a name="130" href="#130">130</a> }<a name="131" href="#131">131</a> <a name="132" href="#132">132</a> <em>/**<em>*</em></em><a name="133" href="#133">133</a> <em> * Get record at passed <code>offset</code>.</em><a name="134" href="#134">134</a> <em> * </em><a name="135" href="#135">135</a> <em> * @param offset Byte index into file at which a record starts.</em><a name="136" href="#136">136</a> <em> * @return An Archive Record reference.</em><a name="137" href="#137">137</a> <em> * @throws IOException</em><a name="138" href="#138">138</a> <em> */</em><a name="139" href="#139">139</a> <strong>public</strong> <a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> get(<strong>long</strong> offset) throws IOException {<a name="140" href="#140">140</a> cleanupCurrentRecord();<a name="141" href="#141">141</a> RepositionableStream ps = (RepositionableStream)<strong>this</strong>.in;<a name="142" href="#142">142</a> <strong>long</strong> currentOffset = ps.position();<a name="143" href="#143">143</a> <strong>if</strong> (currentOffset != offset) {<a name="144" href="#144">144</a> currentOffset = offset;<a name="145" href="#145">145</a> ps.position(offset);<a name="146" href="#146">146</a> }<a name="147" href="#147">147</a> <strong>return</strong> createArchiveRecord(<strong>this</strong>.in, currentOffset);<a name="148" href="#148">148</a> }<a name="149" href="#149">149</a> <a name="150" href="#150">150</a> <em>/**<em>*</em></em><a name="151" href="#151">151</a> <em> * @return Return Archive Record created against current offset.</em><a name="152" href="#152">152</a> <em> * @throws IOException</em><a name="153" href="#153">153</a> <em> */</em><a name="154" href="#154">154</a> <strong>public</strong> <a href="../../../org/archive/io/ArchiveRecord.html">ArchiveRecord</a> get() throws IOException {<a name="155" href="#155">155</a> <strong>return</strong> createArchiveRecord(<strong>this</strong>.in,<a name="156" href="#156">156</a> ((RepositionableStream)<strong>this</strong>.in).position());<a name="157" href="#157">157</a> }<a name="158" href="#158">158</a> <a name="159" href="#159">159</a> <strong>public</strong> <strong>void</strong> close() throws IOException {<a name="160" href="#160">160</a> <strong>if</strong> (<strong>this</strong>.in != <strong>null</strong>) {<a name="161" href="#161">161</a> <strong>this</strong>.in.close();<a name="162" href="#162">162</a> <strong>this</strong>.in = <strong>null</strong>;<a name="163" href="#163">163</a> }<a name="164" href="#164">164</a> }<a name="165" href="#165">165</a> <a name="166" href="#166">166</a> <em>/**<em>*</em></em><a name="167" href="#167">167</a> <em> * Rewinds stream to start of the Archive file.</em><a name="168" href="#168">168</a> <em> * @throws IOException if stream is not resettable.</em><a name="169" href="#169">169</a> <em> */</em><a name="170" href="#170">170</a> <strong>protected</strong> <strong>void</strong> rewind() throws IOException {<a name="171" href="#171">171</a> cleanupCurrentRecord();<a name="172" href="#172">172</a> <strong>if</strong> (<strong>this</strong>.in instanceof RepositionableStream) {<a name="173" href="#173">173</a> <strong>try</strong> {⌨️ 快捷键说明
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