【solr专题之四】关于VelocityResponseWriter
一、關(guān)于Velocity的基本配置
? ? 在Solr中，可以以多種方式返回搜索結(jié)果，如單純的文本回復(fù)（XML、JSON、CSV等），也可以返回velocity，js等格式。而VelocityResponseWriter就是用于將返回velocity類型文本，以便直接用于結(jié)果呈現(xiàn)。
? ? ?在Solr提供的example，其中的一個(gè)RequestHandler--/browse，使用了VelocityResponseWriter。其配置如下：
? ??
<requestHandler name="/browse" class="solr.SearchHandler"><lst name="defaults"><str name="echoParams">explicit</str><!-- VelocityResponseWriter settings --><str name="wt">velocity</str><str name="v.template">browse</str><str name="v.layout">layout</str><str name="title">Solritas_test</str><!-- Query settings --><str name="defType">edismax</str><str name="qf">text^0.5 features^1.0 name^1.2 sku^1.5 id^10.0 manu^1.1 cat^1.4title^10.0 description^5.0 keywords^5.0 author^2.0 resourcename^1.0</str><str name="df">text</str><str name="mm">100%</str><str name="q.alt">*:*</str><str name="rows">10</str><str name="fl">*,score</str><str name="mlt.qf">text^0.5 features^1.0 name^1.2 sku^1.5 id^10.0 manu^1.1 cat^1.4title^10.0 description^5.0 keywords^5.0 author^2.0 resourcename^1.0</str><str name="mlt.fl">text,features,name,sku,id,manu,cat,title,description,keywords,author,resourcename</str><int name="mlt.count">3</int><!-- Faceting defaults --><str name="facet">on</str><str name="facet.field">cat</str><str name="facet.field">manu_exact</str><str name="facet.field">content_type</str><str name="facet.field">author_s</str><str name="facet.query">ipod</str><str name="facet.query">GB</str><str name="facet.mincount">1</str><str name="facet.pivot">cat,inStock</str><str name="facet.range.other">after</str><str name="facet.range">price</str><int name="f.price.facet.range.start">0</int><int name="f.price.facet.range.end">600</int><int name="f.price.facet.range.gap">50</int><str name="facet.range">popularity</str><int name="f.popularity.facet.range.start">0</int><int name="f.popularity.facet.range.end">10</int><int name="f.popularity.facet.range.gap">3</int><str name="facet.range">manufacturedate_dt</str><str name="f.manufacturedate_dt.facet.range.start">NOW/YEAR-10YEARS</str><str name="f.manufacturedate_dt.facet.range.end">NOW</str><str name="f.manufacturedate_dt.facet.range.gap">+1YEAR</str><str name="f.manufacturedate_dt.facet.range.other">before</str><str name="f.manufacturedate_dt.facet.range.other">after</str><!-- Highlighting defaults --><str name="hl">on</str><str name="hl.fl">content features title name</str><str name="hl.encoder">html</str><str name="hl.simple.pre"><b></str><str name="hl.simple.post"></b></str><str name="f.title.hl.fragsize">0</str><str name="f.title.hl.alternateField">title</str><str name="f.name.hl.fragsize">0</str><str name="f.name.hl.alternateField">name</str><str name="f.content.hl.snippets">3</str><str name="f.content.hl.fragsize">200</str><str name="f.content.hl.alternateField">content</str><str name="f.content.hl.maxAlternateFieldLength">750</str><!-- Spell checking defaults --><str name="spellcheck">on</str><str name="spellcheck.extendedResults">false</str><str name="spellcheck.count">5</str><str name="spellcheck.alternativeTermCount">2</str><str name="spellcheck.maxResultsForSuggest">5</str><str name="spellcheck.collate">true</str><str name="spellcheck.collateExtendedResults">true</str><str name="spellcheck.maxCollationTries">5</str><str name="spellcheck.maxCollations">3</str></lst><!-- append spellchecking to our list of components --><arr name="last-components"><str>spellcheck</str></arr></requestHandler>
關(guān)于velocity這個(gè)writer的定義如下：
<!--Custom response writers can be declared as needed...--><queryResponseWriter name="velocity" class="solr.VelocityResponseWriter" startup="lazy"/>處理一個(gè)流程的步驟如下：
1、根據(jù)請(qǐng)求url查找相關(guān)的配置 請(qǐng)求的url為：http://localhost:8983/solr/browse 則在solrConfig.xml中查找 ?/browse的配置，可以得出上述所示的結(jié)果。2、其中有關(guān)velocity的內(nèi)容如下： <requestHandler name="/browse" class="solr.SearchHandler"><lst name="defaults"><str name="echoParams">explicit</str><!-- VelocityResponseWriter settings --><str name="wt">velocity</str><str name="v.template">browse</str><str name="v.layout">layout</str><str name="title">Solritas_test</str>
從上述定義中開始分別查找顯示層的內(nèi)容(vm文件)與處理類的內(nèi)容(wt的實(shí)現(xiàn)類。)
3、定位顯示內(nèi)容模板 根據(jù)v.template屬性，定義到文件browse.vm，注意在配置中省略了后綴名vm。 由于存在v.layout屬性，因此，此屬性的值將作為模板，而v.template中的內(nèi)容將作為$content的內(nèi)容。
-
v.layout: Template name that wraps main template (v.template). Main template renders to a $content that can be used in layout template.
4、定位ResponseWriter? 從第2步的結(jié)果知道，使用的velocity，然后查找這個(gè)wt的定義，可以得到 <queryResponseWriter name="velocity" class="solr.VelocityResponseWriter" startup="lazy"/> 即VelocityResponseWriter實(shí)現(xiàn)類，其定義如下： public class VelocityResponseWriter extends Object implements QueryResponseWriter
與Solr返回Velocity相關(guān)的類只有4個(gè)：
- PageTool
- SolrParamResourceLoader
- SolrVelocityResourceLoader
- VelocityResponseWriter
以下是關(guān)于VelocityResponseWriter的官方說明：http://wiki.apache.org/solr/VelocityResponseWriter
Introduction
VelocityResponseWriter (aka?Solritas) enables Solr to respond with content generated from?Velocity?templates. Along with technologies like SolrJS, this makes Solr itself capable of driving sophisticated search interfaces without the need for an intermediate application server between the browser and Solr.
See?SOLR-620?for more information.
Contents
Instructions to use, Solr 1.4+
These steps will get you up and running for the examples below:
- Download and install Solr 1.4.x
- Fire up Solr: cd example; java -Dsolr.solr.home=../contrib/velocity/src/main/solr/ -jar start.jar
- Index sample docs: cd example/exampledocs; java -jar post.jar *.xml
- Hit the examples below...
Sample Usage
http://localhost:8983/solr/itas
- Renders browse.vm from conf/velocity. Faceted navigation included.
http://localhost:8983/solr/itas?v.template.header=Custom%20Header
- Renders browse.vm, but overrides the header.vm from conf/velocity with the specified value.
http://localhost:8983/solr/itas?debugQuery=true
- Renders browse.vm, adding in explanation views per hit, and a Velocity context dump at the end.
Using the VelocityResponseWriter in Solr Core
The VelocityResponseWriter is still a contrib component in Solr 1.4.x. In order to use it with the core distributions the following steps need to be followed:
The following jars need to be copied from contrib/velocity/src/main/solr/lib/ to $SOLR_HOME/lib:
- apache-solr-velocity-1.4-dev.jar
- velocity-1.6.1.jar
- velocity-tools-2.0-beta3.jar
- commons-beanutils-1.7.0.jar
- commons-collections-3.2.1.jar
The VelocityResponseWriter uses a more recent version of the commons lang jar than the current version of Solr core, so the jar commons-lang-2.4.jar from .../contrib/velocity/src/main/solr/lib/ should replace $SOLR_HOME/lib/commons-lang-2.1.jar
Add some configuration for this?ResponseWriter?to solrconfig.xml like this:
<queryResponseWriter name="velocity" class="org.apache.solr.request.VelocityResponseWriter"/>
Set up a?RequestHandler?in solrconfig.xml:
<requestHandler name="/itas" class="solr.SearchHandler"> <lst name="defaults"> <str name="v.template">browse</str> <str name="v.properties">velocity.properties</str> <str name="v.contentType">text/html;charset=UTF-8</str> <str name="title">Solritas</str> <str name="wt">velocity</str> <str name="defType">dismax</str> <str name="q.alt">*:*</str> <str name="rows">10</str> <str name="fl">*,score</str> <str name="facet">on</str> <str name="facet.field">title</str> <str name="facet.mincount">1</str> <str name="qf"> text^0.5 title^1.5 </str> </lst> <!--<lst name="invariants">--> <!--<str name="v.base_dir">/solr/contrib/velocity/src/main/templates</str>--> <!--</lst>--> </requestHandler>
Copy the .../contrib/velocity/src/main/solr/conf/velocity directory to $SOLR_HOME/conf/. This directory contains the Velocity templates that will be needed by the VelocityResponseWriter, and also a style sheet, main.css. The templates and style sheet can be edited to customize the display.
Instructions to use, Solr 4.0+
These steps will get you up and running for the examples below:
-
Check out Solr trunk: svn co?http://svn.apache.org/viewvc/lucene/dev/branches/branch_4x/
- Build Solr: ant clean example
- Fire up Solr: cd example; java -jar start.jar
- Index sample docs: cd example/exampledocs; java -jar post.jar *.xml
- Hit the examples below...
Sample Usage
http://localhost:8983/solr/browse
- Renders browse.vm from conf/velocity. Faceted navigation included.
http://localhost:8983/solr/browse?v.template.header=Custom%20Header
- Renders browse.vm, but overrides the header.vm from conf/velocity with the specified value.
http://localhost:8983/solr/browse?debugQuery=true
- Renders browse.vm, adding in explanation views per hit, and a Velocity context dump at the end.
Options (All Versions)
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v.template: template name to use, without the .vm suffix. If not specified, "default"[.vm] will be used.
-
v.template.<name>: overrides a file system template
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debugQuery: if true, default view displays explanations for each hit and additional debugging information in the footer.
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v.json: Escapes and wraps Velocity generated response with v.json parameter as a?JavaScript?function.
-
v.layout: Template name that wraps main template (v.template). Main template renders to a $content that can be used in layout template.
-
v.base_dir: overwrites default template load path (conf/velocity/).
-
v.properties: specifies a Velocity properties file to be applied, found using the Solr resource loader mechanism. If not specified, no .properties file is loaded. Example: v.properties=velocity.properties where velocity.properties can be found using Solr's resource loader mechanism, for example in the conf/ directory (not conf/velocity which is for templates only). The .properties file could also be located inside a JAR in the lib/ directory, or other locations.
-
v.contentType: sets the value of the HTTP response's Content-Type header (in case (x)html pages should be UTF-8 (instead of ISO-8859-1) encoded, make sure you set this option to?text/xml;charset=UTF-8?(for XHTML) and?text/html;charset=UTF-8?(for HTML), respectively)
Velocity Context
-
esc: a Velocity?EscapeTool?instance
-
date: a Velocity?ComparisonDateTool?instance
-
list: a Velocity?ListTool?instance
-
math: a Velocity?MathTool?instance
-
number: a Velocity?NumberTool?instance
-
page: a?PageTool?instance. page only is added to the context when response is a?QueryResponse.
-
request: a?SolrQueryRequest
-
response: a?QueryResponse?most of the time, but in some cases where?QueryResponse?doesn't like the request handlers output (AnalysisRequestHandler, for example, causes a?ClassCastException?parsing "response") the response will be a?SolrResponseBase?object.
-
sort: a Velocity?SortTool?instance
TODO
- Ajax suggest
- Integrate/adapt to SolrJS
- Tie in SIMILE Timeline and SIMILE Exhibit
- Add links in default footer to this wiki page, the Solr request as XML format, and SOLR-620
- Fix multi-valued fields issue, and fl parameter usage.
- Work on "dist" target so this works easily with a nightly build.
- Make Velocity tools and engine configuration pluggable
二、Velocity文件定位過程
1、根據(jù)上述分析，首先定位layout.xml
<html> <head>#parse("head.vm") </head><body><div id="admin"><a href="#url_root/#/#core_name">Solr Admin</a></div><div id="header">#parse("header.vm")</div><div id="tabs">#parse("tabs.vm")</div><div id="content">$content</div><div id="footer">#parse("footer.vm")</div></body> </html>2、其中content的內(nèi)容即為browse.vm <div class="pagination">#parse("pagination_top.vm") </div>## Show Error Message, if any <div class="error">#parse("error.vm") </div>## Render Results, actual matching docs <div class="results">#parse("results_list.vm") </div><div class="pagination">#parse("pagination_bottom.vm") </div>
3、browse.vm中最主要的搜索結(jié)果為results_list.vm #*** Render the main Results List*### Usually displayed inside <div class="results">#if($response.response.get('grouped'))#foreach($grouping in $response.response.get('grouped'))#parse("hit_grouped.vm")#end#else#foreach($doc in $response.results)#parse("hit.vm")## Can get an extremely simple view of the doc## which might be nicer for debugging##parse("hit_plain.vm")#end#end
一般情況下使用hit.vm作呈現(xiàn)，它對(duì)頁面作了一些美工。
在某些情況下，如debug的時(shí)候，就使用hit_plain.vm進(jìn)行呈現(xiàn)，此時(shí)將所有的屬性呈現(xiàn)出來。
二者的對(duì)比效果如下：
5、再看看hit.vm
#*** Called for each matching document but then* calls one of product_doc, join_doc or richtext_doc* depending on which fields the doc has*##set($docId = $doc.getFieldValue('id'))<div class="result-document">## Has a "name" field ?#if($doc.getFieldValue('name'))#parse("product_doc.vm")## Has a "compName_s" field ?#elseif($doc.getFieldValue('compName_s'))#parse("join_doc.vm")## Fallback to richtext_doc#else#parse("richtext_doc.vm")#end</div>
#*** Render a complex document in the results list*### Load Mime-Type List and Mapping #parse('mime_type_lists.vm') ## Sets: ## * supportedMimeTypes, AKA supportedtypes ## * mimeExtensionsMap, AKA extMap## Title #if($doc.getFieldValue('title'))#set($title = $esc.html($doc.getFirstValue('title'))) #else#set($title = "["+$doc.getFieldValue('id')+"]") #end## URL #if($doc.getFieldValue('url'))#set($url = $doc.getFieldValue('url')) #elseif($doc.getFieldValue('resourcename'))#set($url = "file:///$doc.getFieldValue('resourcename')") #else#set($url = "$doc.getFieldValue('id')") #end## Sort out Mime-Type #set($ct = $list.get($doc.getFirstValue('content_type').split(";"),0)) #set($filename = $doc.getFieldValue('resourcename')) #set($filetype = false) #set($filetype = $mimeExtensionsMap.get($ct))## TODO: falling back to file extension is convenient, ## except when you don't have an icon for that extension ## example "application/vnd.openxmlformats-officedocument.wordprocessingml.document" ## document with a .docx extension. ## It'd be nice to fall back to an "unknown" or the existing "file" type ## We sort of do this below, but only if the filename has no extension ## (anything after the last dot).#if(!$filetype)#set($filetype = $filename.substring($filename.lastIndexOf(".")).substring(1)) #end## #if(!$filetype) ## #set($filetype = "file") ## #end ## #if(!$supportedMimeTypes.contains($filetype)) ## #set($filetype = "file") ## #end## Row 1: Icon and Title and mlt link <div class="result-title">## Icon## Small file type icons from http://www.splitbrain.org/projects/file_icons (public domain)<img src="#{url_root}/img/filetypes/${filetype}.png" align="center">## Title, hyperlinked<a href="${url}" target="_blank"><b>$title</b></a>## Link for MLT / More Like This / Find Similar<span class="mlt">#if($params.getBool('mlt', false) == false)<a href="#lensNoQ&q=id:%22$docId%22&mlt=true">More Like This</a>#end</span></div>## Row 2?: ID / URL <div>#Id: #field('id')##自己修改##Time: #field('tstamp') </div>## Resource Name <div>#if($doc.getFieldValue('resourcename'))Resource name: $filename #elseif($url)URL: $url#end#if($ct)($ct)#end </div>## Author #if($doc.getFieldValue('author'))<div>Author: #field('author')</div> #end## Last_Modified Date #if($doc.getFieldValue('last_modified'))<div>last-modified:#field('last_modified')</div> #end## Main content of doc <div class="result-body">#field('content') </div>## Display Similar Documents / MLT = More Like This <div class="mlt">#set($mlt = $mltResults.get($docId))#set($mltOn = $params.getBool('mlt'))#if($mltOn == true)<div class="field-name">Similar Items</div>#end## If has MLT enabled An Entries to show#if ($mltOn && $mlt && $mlt.size() > 0)<ul>#foreach($mltHit in $mlt)#set($mltId = $mltHit.getFieldValue('id'))<li><div><a href="#url_for_home?q=id:$mltId">$mltId</a></div><div><span class="field-name">Title:</span>$mltHit.getFieldValue('title')</div><div><span class="field-name">Author:</span>$mltHit.getFieldValue('author')<span class="field-name">Description:</span>$mltHit.getFieldValue('description')</div></li>#end ## end for each mltHit in $mlt</ul>## Else MLT Enabled but no mlt results for this query#elseif($mltOn && $mlt.size() == 0)<div>No Similar Items Found</div>#end </div> ## div class=mlt#parse('debug.vm') 由于本文件是example自帶的呈現(xiàn)文件，其屬性也按照自帶的schemal.xml定義，并不適用于nutch的schema。
因此，若要改變呈現(xiàn)的內(nèi)容，可以直接修改此文件。如將
## Row 2?: ID / URL <div>#Id: #field('id') </div>改為： ## Row 2?: ID / URL <div>##自己修改#Time: #field('tstamp') </div>則在頁面不再顯示id，而是顯示時(shí)間。
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