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【Solr基础教程之X】关于VelocityResponseWriter

2024-07-13 09:47:58 223人阅读

在Solr中，可以以多种方式返回搜索结果，如单纯的文本回复（XML、JSON、CSV等），也可以返回velocity，js等格式。而VelocityResponseWriter就是用于将返回velocity类型文本，以便直接用于结果呈现。

在Solr提供的example，其中的一个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^1.4
          title^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^1.4
         title^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>

关于velocity这个writer的定义如下：

  <!--
     Custom response writers can be declared as needed...
    -->
    <queryResponseWriter name="velocity" class="solr.VelocityResponseWriter" startup="lazy"/>

处理一个流程的步骤如下：

1、根据请求url查找相关的配置

请求的url为：http://localhost:8983/solr/browse

则在solrConfig.xml中查找 /browse的配置，可以得出上述所示的结果。

2、其中有关velocity的内容如下：

  <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>

从上述定义中开始分别查找显示层的内容(vm文件)与处理类的内容(wt的实现类。)

3、定位显示内容模板

根据v.template属性，定义到文件browse.vm，注意在配置中省略了后缀名vm。

由于存在v.layout属性，因此，此属性的值将作为模板，而v.template中的内容将作为$content的内容。

v.layout: Template name that wraps main template (v.template). Main template renders to a $content that can be used in layout template.

layout.vm的内容如下：

#**
 *  Overall HTML page layout
 *#

<html>
<head>
  #parse("head.vm")
</head>
  <body>
    <div id="admin"><a href=http://www.mamicode.com/"#url_root/#/#core_name">Solr Admin

4、定位ResponseWriter

从第2步的结果知道，使用的velocity，然后查找这个wt的定义，可以得到

即VelocityResponseWriter实现类，其定义如下：

public class VelocityResponseWriter
extends Object
implements QueryResponseWriter

与Solr返回Velocity相关的类只有4个：

PageTool
SolrParamResourceLoader
SolrVelocityResourceLoader
VelocityResponseWriter

以下是关于VelocityResponseWriter的官方说明：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

Introduction
Instructions to use, Solr 1.4+
1. Sample Usage
  1. Using the VelocityResponseWriter in Solr Core
Instructions to use, Solr 4.0+
1. Sample Usage
Options (All Versions)
Velocity Context
TODO

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)

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
debugQuery: if true, default view displays explanations for each hit and additional debugging information in the footer.
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

【Solr基础教程之X】关于VelocityResponseWriter

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首页 > 代码库 > 【Solr基础教程之X】关于VelocityResponseWriter

【Solr基础教程之X】关于VelocityResponseWriter

Introduction

Instructions to use, Solr 1.4+

Sample Usage

Using the VelocityResponseWriter in Solr Core

Instructions to use, Solr 4.0+

Sample Usage

Options (All Versions)

Velocity Context

TODO

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