Heritrix 3.1.0 源碼解析（二）

上文Heritrix 3.1.0 源碼解析（一）實際上是講述Heritrix3.1.0在eclipse中的環境搭建，還屬於對Heritrix3.1.0 源碼解析的熱身階段，本文接着分析Heritrix 3.1.0的任務配置，Heritrix3.1.0版本與原來的Heritrix1.14.4版本很大的不同是 任務配置文件從order.xml文件轉到了crawler-beans.cxml文件，而crawler-beans.cxml實際上是一個spring的容器配置文件，是用spring管理的，我們先來眼熟一下該文件的樣子（這里面我配置了一個任務）：

<?xml version="1.0" encoding="UTF-8"?>
<!-- 
  HERITRIX 3 CRAWL JOB CONFIGURATION FILE
  
   This is a relatively minimal configuration suitable for many crawls.
   
   Commented-out beans and properties are provided as an example; values
   shown in comments reflect the actual defaults which are in effect
   if not otherwise specified specification. (To change from the default 
   behavior, uncomment AND alter the shown values.)   
 -->
<beans xmlns="http://www.springframework.org/schema/beans"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns:context="http://www.springframework.org/schema/context"
         xmlns:aop="http://www.springframework.org/schema/aop"
         xmlns:tx="http://www.springframework.org/schema/tx"
         xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
           http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
           http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
 
 <context:annotation-config/>

<!-- 
  OVERRIDES
   Values elsewhere in the configuration may be replaced ('overridden') 
   by a Properties map declared in a PropertiesOverrideConfigurer, 
   using a dotted-bean-path to address individual bean properties. 
   This allows us to collect a few of the most-often changed values
   in an easy-to-edit format here at the beginning of the model
   configuration.    
 -->
 <!-- overrides from a text property list -->
 <bean id="simpleOverrides" class="org.springframework.beans.factory.config.PropertyOverrideConfigurer">
  <property name="properties">
   <value>
# This Properties map is specified in the Java 'property list' text format
# http://java.sun.com/javase/6/docs/api/java/util/Properties.html#load%28java.io.Reader%29

metadata.operatorContactUrl=http://localhost
metadata.jobName=myjob1
metadata.description=myjob1 descrition

##..more?..##
   </value>
  </property>
 </bean>

 <!-- overrides from declared <prop> elements, more easily allowing
      multiline values or even declared beans -->
 <bean id="longerOverrides" class="org.springframework.beans.factory.config.PropertyOverrideConfigurer">
  <property name="properties">
   <props>
    <prop key="seeds.textSource.value">

# URLS HERE
http://www.watiao.net

    </prop>
   </props>
  </property>
 </bean>

 <!-- CRAWL METADATA: including identification of crawler/operator -->
 <bean id="metadata" class="org.archive.modules.CrawlMetadata" autowire="byName">
       <property name="operatorContactUrl" value="http://localhost"/>
       <property name="jobName" value="myjob1"/>
       <property name="description" value="myjob1 descrition"/>
  <!-- <property name="robotsPolicyName" value="obey"/> -->
  <!-- <property name="operator" value=""/> -->
  <!-- <property name="operatorFrom" value=""/> -->
  <!-- <property name="organization" value=""/> -->
  <!-- <property name="audience" value=""/> -->
  <!-- <property name="userAgentTemplate" 
         value="Mozilla/5.0 (compatible; heritrix/3.1.0 [e-mail])"/> -->
       
 </bean>
 
 <!-- SEEDS: crawl starting points 
      ConfigString allows simple, inline specification of a moderate
      number of seeds; see below comment for example of using an
      arbitrarily-large external file. -->
 <bean id="seeds" class="org.archive.modules.seeds.TextSeedModule">
     <property name="textSource">
      <bean class="org.archive.spring.ConfigString">
       <property name="value">
        <value>
# [see override above]
        </value>
       </property>
      </bean>
     </property>
<!-- <property name='sourceTagSeeds' value='false'/> -->
<!-- <property name='blockAwaitingSeedLines' value='-1'/> -->
 </bean>
 
 <!-- SEEDS ALTERNATE APPROACH: specifying external seeds.txt file in
      the job directory, similar to the H1 approach. 
      Use either the above, or this, but not both. -->
 <!-- 
 <bean id="seeds" class="org.archive.modules.seeds.TextSeedModule">
  <property name="textSource">
   <bean class="org.archive.spring.ConfigFile">
    <property name="path" value="seeds.txt" />
   </bean>
  </property>
  <property name='sourceTagSeeds' value='false'/>
  <property name='blockAwaitingSeedLines' value='-1'/>
 </bean>
  -->
 
 <!-- SCOPE: rules for which discovered URIs to crawl; order is very 
      important because last decision returned other than 'NONE' wins. -->
 <bean id="scope" class="org.archive.modules.deciderules.DecideRuleSequence">
  <!-- <property name="logToFile" value="false" /> -->
  <property name="rules">
   <list>
    <!-- Begin by REJECTing all... -->
    <bean class="org.archive.modules.deciderules.RejectDecideRule">
    </bean>
    <!-- ...then ACCEPT those within configured/seed-implied SURT prefixes... -->
    <bean class="org.archive.modules.deciderules.surt.SurtPrefixedDecideRule">
     <!-- <property name="seedsAsSurtPrefixes" value="true" /> -->
     <!-- <property name="alsoCheckVia" value="false" /> -->
     <!-- <property name="surtsSourceFile" value="" /> -->
     <!-- <property name="surtsDumpFile" value="${launchId}/surts.dump" /> -->
     <!-- <property name="surtsSource">
           <bean class="org.archive.spring.ConfigString">
            <property name="value">
             <value>
              # example.com
              # http://www.example.edu/path1/
              # +http://(org,example,
             </value>
            </property> 
           </bean>
          </property> -->
    </bean>
    <!-- ...but REJECT those more than a configured link-hop-count from start... -->
    <bean class="org.archive.modules.deciderules.TooManyHopsDecideRule">
     <!-- <property name="maxHops" value="20" /> -->
    </bean>
    <!-- ...but ACCEPT those more than a configured link-hop-count from start... -->
    <bean class="org.archive.modules.deciderules.TransclusionDecideRule">
     <!-- <property name="maxTransHops" value="2" /> -->
     <!-- <property name="maxSpeculativeHops" value="1" /> -->
    </bean>
    <!-- ...but REJECT those from a configurable (initially empty) set of REJECT SURTs... -->
    <bean class="org.archive.modules.deciderules.surt.SurtPrefixedDecideRule">
          <property name="decision" value="REJECT"/>
          <property name="seedsAsSurtPrefixes" value="false"/>
          <property name="surtsDumpFile" value="${launchId}/negative-surts.dump" /> 
     <!-- <property name="surtsSource">
           <bean class="org.archive.spring.ConfigFile">
            <property name="path" value="negative-surts.txt" />
           </bean>
          </property> -->
    </bean>
    <!-- ...and REJECT those from a configurable (initially empty) set of URI regexes... -->
    <bean class="org.archive.modules.deciderules.MatchesListRegexDecideRule">
          <property name="decision" value="REJECT"/>
     <!-- <property name="listLogicalOr" value="true" /> -->
     <!-- <property name="regexList">
           <list>
           </list>
          </property> -->
    </bean>
    <!-- ...and REJECT those with suspicious repeating path-segments... -->
    <bean class="org.archive.modules.deciderules.PathologicalPathDecideRule">
     <!-- <property name="maxRepetitions" value="2" /> -->
    </bean>
    <!-- ...and REJECT those with more than threshold number of path-segments... -->
    <bean class="org.archive.modules.deciderules.TooManyPathSegmentsDecideRule">
     <!-- <property name="maxPathDepth" value="20" /> -->
    </bean>
    <!-- ...but always ACCEPT those marked as prerequisitee for another URI... -->
    <bean class="org.archive.modules.deciderules.PrerequisiteAcceptDecideRule">
    </bean>
    <!-- ...but always REJECT those with unsupported URI schemes -->
    <bean class="org.archive.modules.deciderules.SchemeNotInSetDecideRule">
    </bean>
   </list>
  </property>
 </bean>
 
 <!-- 
   PROCESSING CHAINS
    Much of the crawler's work is specified by the sequential 
    application of swappable Processor modules. These Processors
    are collected into three 'chains'. The CandidateChain is applied 
    to URIs being considered for inclusion, before a URI is enqueued
    for collection. The FetchChain is applied to URIs when their 
    turn for collection comes up. The DispositionChain is applied 
    after a URI is fetched and analyzed/link-extracted.
  -->
  
 <!-- CANDIDATE CHAIN --> 
 <!-- first, processors are declared as top-level named beans -->
 <bean id="candidateScoper" class="org.archive.crawler.prefetch.CandidateScoper">
 </bean>
 <bean id="preparer" class="org.archive.crawler.prefetch.FrontierPreparer">
  <!-- <property name="preferenceDepthHops" value="-1" /> -->
  <!-- <property name="preferenceEmbedHops" value="1" /> -->
  <!-- <property name="canonicalizationPolicy"> 
        <ref bean="canonicalizationPolicy" />
       </property> -->
  <!-- <property name="queueAssignmentPolicy"> 
        <ref bean="queueAssignmentPolicy" />
       </property> -->
  <!-- <property name="uriPrecedencePolicy"> 
        <ref bean="uriPrecedencePolicy" />
       </property> -->
  <!-- <property name="costAssignmentPolicy"> 
        <ref bean="costAssignmentPolicy" />
       </property> -->
 </bean>
 <!-- now, processors are assembled into ordered CandidateChain bean -->
 <bean id="candidateProcessors" class="org.archive.modules.CandidateChain">
  <property name="processors">
   <list>
    <!-- apply scoping rules to each individual candidate URI... -->
    <ref bean="candidateScoper"/>
    <!-- ...then prepare those ACCEPTed to be enqueued to frontier. -->
    <ref bean="preparer"/>
   </list>
  </property>
 </bean>
  
 <!-- FETCH CHAIN --> 
 <!-- first, processors are declared as top-level named beans -->
 <bean id="preselector" class="org.archive.crawler.prefetch.MyPreselector">
      <!-- <property name="recheckScope" value="false" />-->
     <!--  <property name="blockAll" value="false" />-->
     <!--  <property name="blockByRegex" value="" />-->
     <!--  <property name="allowByRegex" value="" />-->
 </bean>
 <bean id="preconditions" class="org.archive.crawler.prefetch.PreconditionEnforcer">
  <!-- <property name="ipValidityDurationSeconds" value="21600" /> -->
  <!-- <property name="robotsValidityDurationSeconds" value="86400" /> -->
  <!-- <property name="calculateRobotsOnly" value="false" /> -->
 </bean>
 <bean id="fetchDns" class="org.archive.modules.fetcher.FetchDNS">
  <!-- <property name="acceptNonDnsResolves" value="false" /> -->
  <!-- <property name="digestContent" value="true" /> -->
  <!-- <property name="digestAlgorithm" value="sha1" /> -->
 </bean>
 <!-- <bean id="fetchWhois" class="org.archive.modules.fetcher.FetchWhois">
       <property name="specialQueryTemplates">
        <map>
         <entry key="whois.verisign-grs.com" value="domain %s" />
         <entry key="whois.arin.net" value="z + %s" />
         <entry key="whois.denic.de" value="-T dn %s" />
        </map>
       </property> 
      </bean> -->
 <bean id="fetchHttp" class="org.archive.modules.fetcher.FetchHTTP">
  <!-- <property name="useHTTP11" value="false" /> -->
  <!-- <property name="maxLengthBytes" value="0" /> -->
  <!-- <property name="timeoutSeconds" value="1200" /> -->
  <!-- <property name="maxFetchKBSec" value="0" /> -->
  <!-- <property name="defaultEncoding" value="ISO-8859-1" /> -->
  <!-- <property name="shouldFetchBodyRule"> 
        <bean class="org.archive.modules.deciderules.AcceptDecideRule"/>
       </property> -->
  <!-- <property name="soTimeoutMs" value="20000" /> -->
  <!-- <property name="sendIfModifiedSince" value="true" /> -->
  <!-- <property name="sendIfNoneMatch" value="true" /> -->
  <!-- <property name="sendConnectionClose" value="true" /> -->
  <!-- <property name="sendReferer" value="true" /> -->
  <!-- <property name="sendRange" value="false" /> -->
  <!-- <property name="ignoreCookies" value="false" /> -->
  <!-- <property name="sslTrustLevel" value="OPEN" /> -->
  <!-- <property name="acceptHeaders"> 
        <list>
         <value>Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8</value>
        </list>
       </property>
  -->
  <!-- <property name="httpBindAddress" value="" /> -->
  <!-- <property name="httpProxyHost" value="" /> -->
  <!-- <property name="httpProxyPort" value="0" /> -->
  <!-- <property name="httpProxyUser" value="" /> -->
  <!-- <property name="httpProxyPassword" value="" /> -->
  <!-- <property name="digestContent" value="true" /> -->
  <!-- <property name="digestAlgorithm" value="sha1" /> -->
 </bean>
 <bean id="extractorHttp" class="org.archive.modules.extractor.ExtractorHTTP">
 </bean>
 <bean id="extractorHtml" class="org.archive.modules.extractor.ExtractorHTML">
  <!-- <property name="extractJavascript" value="true" /> -->
  <!-- <property name="extractValueAttributes" value="true" /> -->
  <!-- <property name="ignoreFormActionUrls" value="false" /> -->
  <!-- <property name="extractOnlyFormGets" value="true" /> -->
  <!-- <property name="treatFramesAsEmbedLinks" value="true" /> -->
  <!-- <property name="ignoreUnexpectedHtml" value="true" /> -->
  <!-- <property name="maxElementLength" value="1024" /> -->
  <!-- <property name="maxAttributeNameLength" value="1024" /> -->
  <!-- <property name="maxAttributeValueLength" value="16384" /> -->
 </bean>
 <bean id="extractorCss" class="org.archive.modules.extractor.ExtractorCSS">
 </bean> 
 <bean id="extractorJs" class="org.archive.modules.extractor.ExtractorJS">
 </bean>
 <bean id="extractorSwf" class="org.archive.modules.extractor.ExtractorSWF">
 </bean>    
 <!-- now, processors are assembled into ordered FetchChain bean -->
 <bean id="fetchProcessors" class="org.archive.modules.FetchChain">
  <property name="processors">
   <list>
    <!-- re-check scope, if so enabled... -->
    <ref bean="preselector"/>
    <!-- ...then verify or trigger prerequisite URIs fetched, allow crawling... -->
    <ref bean="preconditions"/>
    <!-- ...fetch if DNS URI... -->
    <ref bean="fetchDns"/>
    <!-- <ref bean="fetchWhois"/> -->
    <!-- ...fetch if HTTP URI... -->
    <ref bean="fetchHttp"/>
    <!-- ...extract outlinks from HTTP headers... -->
    <ref bean="extractorHttp"/>
    <!-- ...extract outlinks from HTML content... -->
    <ref bean="extractorHtml"/>
    <!-- ...extract outlinks from CSS content... -->
    <ref bean="extractorCss"/>
    <!-- ...extract outlinks from Javascript content... -->
    <ref bean="extractorJs"/>
    <!-- ...extract outlinks from Flash content... -->
    <ref bean="extractorSwf"/>
   </list>
  </property>
 </bean>
  
 <!-- DISPOSITION CHAIN -->
 <!-- first, processors are declared as top-level named beans  -->
 <bean id="warcWriter" class="org.archive.modules.writer.MirrorWriterProcessor">
  <!-- <property name="compress" value="true" /> -->
  <!-- <property name="prefix" value="IAH" /> -->
  <!-- <property name="suffix" value="${HOSTNAME}" /> -->
  <!-- <property name="maxFileSizeBytes" value="1000000000" /> -->
  <!-- <property name="poolMaxActive" value="1" /> -->
  <!-- <property name="MaxWaitForIdleMs" value="500" /> -->
  <!-- <property name="skipIdenticalDigests" value="false" /> -->
  <!-- <property name="maxTotalBytesToWrite" value="0" /> -->
  <!-- <property name="directory" value="${launchId}" /> -->
  <!-- <property name="storePaths">
        <list>
         <value>warcs</value>
        </list>
       </property> -->
  <!-- <property name="writeRequests" value="true" /> -->
  <!-- <property name="writeMetadata" value="true" /> -->
  <!-- <property name="writeRevisitForIdenticalDigests" value="true" /> -->
  <!-- <property name="writeRevisitForNotModified" value="true" /> -->
 </bean>
 <bean id="candidates" class="org.archive.crawler.postprocessor.CandidatesProcessor">
  <!-- <property name="seedsRedirectNewSeeds" value="true" /> -->
 </bean>
 <bean id="disposition" class="org.archive.crawler.postprocessor.DispositionProcessor">
  <!-- <property name="delayFactor" value="5.0" /> -->
  <!-- <property name="minDelayMs" value="3000" /> -->
  <!-- <property name="respectCrawlDelayUpToSeconds" value="300" /> -->
  <!-- <property name="maxDelayMs" value="30000" /> -->
  <!-- <property name="maxPerHostBandwidthUsageKbSec" value="0" /> -->
 </bean>
 <!-- <bean id="rescheduler" class="org.archive.crawler.postprocessor.ReschedulingProcessor">
       <property name="rescheduleDelaySeconds" value="-1" />
      </bean> -->
 <!-- now, processors are assembled into ordered DispositionChain bean -->
 <bean id="dispositionProcessors" class="org.archive.modules.DispositionChain">
  <property name="processors">
   <list>
    <!-- write to aggregate archival files... -->
    <ref bean="warcWriter"/>
    <!-- ...send each outlink candidate URI to CandidateChain, 
         and enqueue those ACCEPTed to the frontier... -->
    <ref bean="candidates"/>
    <!-- ...then update stats, shared-structures, frontier decisions -->
    <ref bean="disposition"/>
    <!-- <ref bean="rescheduler" /> -->
   </list>
  </property>
 </bean>
 
 <!-- CRAWLCONTROLLER: Control interface, unifying context -->
 <bean id="crawlController" 
   class="org.archive.crawler.framework.CrawlController">
  <!-- <property name="maxToeThreads" value="25" /> -->
  <!-- <property name="pauseAtStart" value="true" /> -->
  <!-- <property name="runWhileEmpty" value="false" /> -->
  <!-- <property name="recorderInBufferBytes" value="524288" /> -->
  <!-- <property name="recorderOutBufferBytes" value="16384" /> -->
  <!-- <property name="scratchDir" value="scratch" /> -->
 </bean>
 
 <!-- FRONTIER: Record of all URIs discovered and queued-for-collection -->
 <bean id="frontier" 
   class="org.archive.crawler.frontier.BdbFrontier">
  <!-- <property name="queueTotalBudget" value="-1" /> -->
  <!-- <property name="balanceReplenishAmount" value="3000" /> -->
  <!-- <property name="errorPenaltyAmount" value="100" /> -->
  <!-- <property name="precedenceFloor" value="255" /> -->
  <!-- <property name="queuePrecedencePolicy">
        <bean class="org.archive.crawler.frontier.precedence.BaseQueuePrecedencePolicy" />
       </property> -->
  <!-- <property name="snoozeLongMs" value="300000" /> -->
  <!-- <property name="retryDelaySeconds" value="900" /> -->
  <!-- <property name="maxRetries" value="30" /> -->
  <!-- <property name="recoveryLogEnabled" value="true" /> -->
  <!-- <property name="maxOutlinks" value="6000" /> -->
  <!-- <property name="extractIndependently" value="false" /> -->
  <!-- <property name="outbound">
        <bean class="java.util.concurrent.ArrayBlockingQueue">
         <constructor-arg value="200"/>
         <constructor-arg value="true"/>
        </bean>
       </property> -->
  <!-- <property name="inbound">
        <bean class="java.util.concurrent.ArrayBlockingQueue">
         <constructor-arg value="40000"/>
         <constructor-arg value="true"/>
        </bean>
       </property> -->
  <!-- <property name="dumpPendingAtClose" value="false" /> -->
 </bean>
 
 <!-- URI UNIQ FILTER: Used by frontier to remember already-included URIs --> 
 <bean id="uriUniqFilter" 
   class="org.archive.crawler.util.BdbUriUniqFilter">
 </bean>
 
 <!--
   EXAMPLE SETTINGS OVERLAY SHEETS
   Sheets allow some settings to vary by context - usually by URI context,
   so that different sites or sections of sites can be treated differently. 
   Here are some example Sheets for common purposes. The SheetOverlaysManager
   (below) automatically collects all Sheet instances declared among the 
   original beans, but others can be added during the crawl via the scripting 
   interface.
  -->

<!-- forceRetire: any URI to which this sheet's settings are applied 
     will force its containing queue to 'retired' status. -->
<bean id='forceRetire' class='org.archive.spring.Sheet'>
 <property name='map'>
  <map>
   <entry key='disposition.forceRetire' value='true'/>
  </map>
 </property>
</bean>

<!-- smallBudget: any URI to which this sheet's settings are applied 
     will give its containing queue small values for balanceReplenishAmount 
     (causing it to have shorter 'active' periods while other queues are 
     waiting) and queueTotalBudget (causing the queue to enter 'retired' 
     status once that expenditure is reached by URI attempts and errors) -->
<bean id='smallBudget' class='org.archive.spring.Sheet'>
 <property name='map'>
  <map>
   <entry key='frontier.balanceReplenishAmount' value='20'/>
   <entry key='frontier.queueTotalBudget' value='100'/>
  </map>
 </property>
</bean>

<!-- veryPolite: any URI to which this sheet's settings are applied 
     will cause its queue to take extra-long politeness snoozes -->
<bean id='veryPolite' class='org.archive.spring.Sheet'>
 <property name='map'>
  <map>
   <entry key='disposition.delayFactor' value='10'/>
   <entry key='disposition.minDelayMs' value='10000'/>
   <entry key='disposition.maxDelayMs' value='1000000'/>
   <entry key='disposition.respectCrawlDelayUpToSeconds' value='3600'/>
  </map>
 </property>
</bean>

<!-- highPrecedence: any URI to which this sheet's settings are applied 
     will give its containing queue a slightly-higher than default 
     queue precedence value. That queue will then be preferred over 
     other queues for active crawling, never waiting behind lower-
     precedence queues. -->
<bean id='highPrecedence' class='org.archive.spring.Sheet'>
 <property name='map'>
  <map>
   <entry key='frontier.balanceReplenishAmount' value='20'/>
   <entry key='frontier.queueTotalBudget' value='100'/>
  </map>
 </property>
</bean>

<!--
   EXAMPLE SETTINGS OVERLAY SHEET-ASSOCIATION
   A SheetAssociation says certain URIs should have certain overlay Sheets
   applied. This example applies two sheets to URIs matching two SURT-prefixes.
   New associations may also be added mid-crawl using the scripting facility.
  -->

<!--
<bean class='org.archive.crawler.spring.SurtPrefixesSheetAssociation'>
 <property name='surtPrefixes'>
  <list>
   <value>http://(org,example,</value>
   <value>http://(com,example,www,)/</value>
  </list>
 </property>
 <property name='targetSheetNames'>
  <list>
   <value>veryPolite</value>
   <value>smallBudget</value>
  </list>
 </property>
</bean>
-->

 <!-- 
   OPTIONAL BUT RECOMMENDED BEANS
  -->
  
 <!-- ACTIONDIRECTORY: disk directory for mid-crawl operations
      Running job will watch directory for new files with URIs, 
      scripts, and other data to be processed during a crawl. -->
 <bean id="actionDirectory" class="org.archive.crawler.framework.ActionDirectory">
  <!-- <property name="actionDir" value="action" /> -->
  <!-- <property name="doneDir" value="${launchId}/actions-done" /> -->
  <!-- <property name="initialDelaySeconds" value="10" /> -->
  <!-- <property name="delaySeconds" value="30" /> -->
 </bean> 
 
 <!--  CRAWLLIMITENFORCER: stops crawl when it reaches configured limits -->
 <bean id="crawlLimiter" class="org.archive.crawler.framework.CrawlLimitEnforcer">
  <!-- <property name="maxBytesDownload" value="0" /> -->
  <!-- <property name="maxDocumentsDownload" value="0" /> -->
  <!-- <property name="maxTimeSeconds" value="0" /> -->
 </bean>
 
 <!-- CHECKPOINTSERVICE: checkpointing assistance -->
 <bean id="checkpointService" 
   class="org.archive.crawler.framework.CheckpointService">
  <!-- <property name="checkpointIntervalMinutes" value="-1"/> -->
  <!-- <property name="checkpointsDir" value="checkpoints"/> -->
 </bean>
 
 <!-- 
   OPTIONAL BEANS
    Uncomment and expand as needed, or if non-default alternate 
    implementations are preferred.
  -->
  
 <!-- CANONICALIZATION POLICY -->
 <!--
 <bean id="canonicalizationPolicy" 
   class="org.archive.modules.canonicalize.RulesCanonicalizationPolicy">
   <property name="rules">
    <list>
     <bean class="org.archive.modules.canonicalize.LowercaseRule" />
     <bean class="org.archive.modules.canonicalize.StripUserinfoRule" />
     <bean class="org.archive.modules.canonicalize.StripWWWNRule" />
     <bean class="org.archive.modules.canonicalize.StripSessionIDs" />
     <bean class="org.archive.modules.canonicalize.StripSessionCFIDs" />
     <bean class="org.archive.modules.canonicalize.FixupQueryString" />
    </list>
  </property>
 </bean>
 -->
 

 <!-- QUEUE ASSIGNMENT POLICY -->
 <!--
 <bean id="queueAssignmentPolicy" 
   class="org.archive.crawler.frontier.SurtAuthorityQueueAssignmentPolicy">
  <property name="forceQueueAssignment" value="" />
  <property name="deferToPrevious" value="true" />
  <property name="parallelQueues" value="1" />
 </bean>
 -->
 
 <!-- URI PRECEDENCE POLICY -->
 <!--
 <bean id="uriPrecedencePolicy" 
   class="org.archive.crawler.frontier.precedence.CostUriPrecedencePolicy">
 </bean>
 -->
 
 <!-- COST ASSIGNMENT POLICY -->
 <!--
 <bean id="costAssignmentPolicy" 
   class="org.archive.crawler.frontier.UnitCostAssignmentPolicy">
 </bean>
 -->
 
 <!-- CREDENTIAL STORE: HTTP authentication or FORM POST credentials -->
 <!-- 
 <bean id="credentialStore" 
   class="org.archive.modules.credential.CredentialStore">
 </bean>
 -->
 
 <!-- DISK SPACE MONITOR: 
      Pauses the crawl if disk space at monitored paths falls below minimum threshold -->
 <!-- 
 <bean id="diskSpaceMonitor" class="org.archive.crawler.monitor.DiskSpaceMonitor">
   <property name="pauseThresholdMiB" value="500" />
   <property name="monitorConfigPaths" value="true" />
   <property name="monitorPaths">
     <list>
       <value>PATH</value>
     </list>
   </property>
 </bean>
 -->
 
 <!-- 
   REQUIRED STANDARD BEANS
    It will be very rare to replace or reconfigure the following beans.
  -->

 <!-- STATISTICSTRACKER: standard stats/reporting collector -->
 <bean id="statisticsTracker" 
   class="org.archive.crawler.reporting.StatisticsTracker" autowire="byName">
  <!-- <property name="reports">
        <list>
         <bean id="crawlSummaryReport" class="org.archive.crawler.reporting.CrawlSummaryReport" />
         <bean id="seedsReport" class="org.archive.crawler.reporting.SeedsReport" />
         <bean id="hostsReport" class="org.archive.crawler.reporting.HostsReport" />
         <bean id="sourceTagsReport" class="org.archive.crawler.reporting.SourceTagsReport" />
         <bean id="mimetypesReport" class="org.archive.crawler.reporting.MimetypesReport" />
         <bean id="responseCodeReport" class="org.archive.crawler.reporting.ResponseCodeReport" />
         <bean id="processorsReport" class="org.archive.crawler.reporting.ProcessorsReport" />
         <bean id="frontierSummaryReport" class="org.archive.crawler.reporting.FrontierSummaryReport" />
         <bean id="frontierNonemptyReport" class="org.archive.crawler.reporting.FrontierNonemptyReport" />
         <bean id="toeThreadsReport" class="org.archive.crawler.reporting.ToeThreadsReport" />
        </list>
       </property> -->
  <!-- <property name="reportsDir" value="${launchId}/reports" /> -->
  <!-- <property name="liveHostReportSize" value="20" /> -->
  <!-- <property name="intervalSeconds" value="20" /> -->
  <!-- <property name="keepSnapshotsCount" value="5" /> -->
  <!-- <property name="liveHostReportSize" value="20" /> -->
 </bean>
 
 <!-- CRAWLERLOGGERMODULE: shared logging facility -->
 <bean id="loggerModule" 
   class="org.archive.crawler.reporting.CrawlerLoggerModule">
  <!-- <property name="path" value="${launchId}/logs" /> -->
  <!-- <property name="crawlLogPath" value="crawl.log" /> -->
  <!-- <property name="alertsLogPath" value="alerts.log" /> -->
  <!-- <property name="progressLogPath" value="progress-statistics.log" /> -->
  <!-- <property name="uriErrorsLogPath" value="uri-errors.log" /> -->
  <!-- <property name="runtimeErrorsLogPath" value="runtime-errors.log" /> -->
  <!-- <property name="nonfatalErrorsLogPath" value="nonfatal-errors.log" /> -->
  <!-- <property name="logExtraInfo" value="false" /> -->
 </bean>
 
 <!-- SHEETOVERLAYMANAGER: manager of sheets of contextual overlays
      Autowired to include any SheetForSurtPrefix or 
      SheetForDecideRuled beans -->
 <bean id="sheetOverlaysManager" autowire="byType"
   class="org.archive.crawler.spring.SheetOverlaysManager">
 </bean>

 <!-- BDBMODULE: shared BDB-JE disk persistence manager -->
 <bean id="bdb" 
  class="org.archive.bdb.BdbModule">
  <!-- <property name="dir" value="state" /> -->
  <!-- <property name="cachePercent" value="60" /> -->
  <!-- <property name="useSharedCache" value="true" /> -->
  <!-- <property name="expectedConcurrency" value="25" /> -->
 </bean>
 
 <!-- BDBCOOKIESTORAGE: disk-based cookie storage for FetchHTTP -->
 <bean id="cookieStorage" 
   class="org.archive.modules.fetcher.BdbCookieStorage">
  <!-- <property name="cookiesLoadFile"><null/></property> -->
  <!-- <property name="cookiesSaveFile"><null/></property> -->
  <!-- <property name="bdb">
        <ref bean="bdb"/>
       </property> -->
 </bean>
 
 <!-- SERVERCACHE: shared cache of server/host info -->
 <bean id="serverCache" 
   class="org.archive.modules.net.BdbServerCache">
  <!-- <property name="bdb">
        <ref bean="bdb"/>
       </property> -->
 </bean>

 <!-- CONFIG PATH CONFIGURER: required helper making crawl paths relative
      to crawler-beans.cxml file, and tracking crawl files for web UI -->
 <bean id="configPathConfigurer" 
   class="org.archive.spring.ConfigPathConfigurer">
 </bean>
 
</beans>

粗看上去，我們大概能夠明白新版本的采集任務配置在bean屬性里面，bean之間還存在一些依賴關系

前面部分顯然是加載任務種子

<bean id="longerOverrides" class="org.springframework.beans.factory.config.PropertyOverrideConfigurer"></bean>

<bean id="metadata" class="org.archive.modules.CrawlMetadata" autowire="byName"></bean>

<bean id="seeds" class="org.archive.modules.seeds.TextSeedModule"></bean>

scope控制CrawlURI是ACCEPT NONE, 還是REJECT的決策，在org.archive.modules.Processor 的process(CrawlURI uri) 方法被調用

<bean id="scope" class="org.archive.modules.deciderules.DecideRuleSequence"></bean>

再下面部分是處理器鏈及相關處理器的依賴關系

我通過打印輸出了Heritrix3.1.0的處理器鏈的結構，下面可以看到FetchChain、DispositionChain、CandidateChain三類處理器鏈各自所依賴的處理器（CandidateChain處理器鏈實際是DispositionChain處理器鏈中的CandidatesProcessor處理器所引用的）修正

FetchChain:org.archive.modules.FetchChain

org.archive.crawler.prefetch.Preselector
org.archive.crawler.prefetch.PreconditionEnforcer
org.archive.modules.fetcher.FetchDNS
org.archive.modules.fetcher.FetchHTTP
org.archive.modules.extractor.ExtractorHTTP
org.archive.modules.extractor.ExtractorHTML
org.archive.modules.extractor.ExtractorCSS
org.archive.modules.extractor.ExtractorJS
org.archive.modules.extractor.ExtractorSWF

Frontier:org.archive.crawler.frontier.BdbFrontier

DispositionChain:org.archive.modules.DispositionChain

org.archive.modules.writer.MirrorWriterProcessor
org.archive.crawler.postprocessor.CandidatesProcessor
org.archive.crawler.postprocessor.DispositionProcessor

CandidateChain:org.archive.modules.CandidateChain

org.archive.crawler.prefetch.CandidateScoper
org.archive.crawler.prefetch.FrontierPreparer

正好與上面的crawler-beans.cxml文件相互印證

crawler-beans.cxml文件后面部分的主要是為前面的處理器設置值（用於自定義設置相關采集地址與處理器對象的屬性值的映射）

<bean id='forceRetire' class='org.archive.spring.Sheet'></bean>

<bean id='smallBudget' class='org.archive.spring.Sheet'></bean>

<bean id='veryPolite' class='org.archive.spring.Sheet'></bean>

<bean id='highPrecedence' class='org.archive.spring.Sheet'></bean>

后面這個名稱為sheetOverlaysManager的bean是管理上面的Sheet部分與處理器的屬性值的加載的

<bean id="sheetOverlaysManager" autowire="byType" class="org.archive.crawler.spring.SheetOverlaysManager"></bean>

后面的比較容易理解，其實crawler-beans.cxml文件里面的英文注釋已經比較清楚了

<bean id="actionDirectory" class="org.archive.crawler.framework.ActionDirectory"></bean>

<bean id="crawlLimiter" class="org.archive.crawler.framework.CrawlLimitEnforcer"></bean>

<bean id="checkpointService" class="org.archive.crawler.framework.CheckpointService"></bean>

<bean id="statisticsTracker" class="org.archive.crawler.reporting.StatisticsTracker" autowire="byName"></bean>

<bean id="loggerModule" class="org.archive.crawler.reporting.CrawlerLoggerModule"></bean>

<bean id="bdb" class="org.archive.bdb.BdbModule"></bean>

<bean id="cookieStorage" class="org.archive.modules.fetcher.BdbCookieStorage">

<bean id="serverCache"    class="org.archive.modules.net.BdbServerCache"></bean>

<bean id="configPathConfigurer" class="org.archive.spring.ConfigPathConfigurer"></bean>

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本系列Heritrix 3.1.0 源碼解析系本人原創

轉載請注明出處 博客園 刺蝟的溫馴

本文鏈接 http://www.cnblogs.com/chenying99/archive/2013/04/10/3013284.html

DispositionChain