Apache Solr 实现去掉重复的搜索结果

　打上SOLR-236_collapsing.patch补丁，实现 solr 搜索结果折叠、除去重复的搜索结果，可以实现类似google搜索结果的“站内的其它相关信息 ”。solr collapsing patch 是用 hash 某个字段来实现折叠重复结果的。下面我演示下应用这个补丁并搜索试用下。

 

其实 solr 上已经有了这功能的实现：solr 1.3 collapse patch， 请看：https://issues.apache.org/jira/browse/SOLR-236 ，我这里下载是了新的：https://issues.apache.org/jira/secure/attachment/12403590/SOLR-236_collapsing.patch 。

下载 好后就需要打上补丁了，先准备一份源码在D:/apache-solr-1.3.0目录下。没有可以去下载：http: //archive.apache.org/dist/lucene/solr/1.3.0/apache-solr-1.3.0.zip。把SOLR- 236_collapsing.patch文件放在D:/apache-solr-1.3.0目录下， 打补丁有我知道的有两种：用linux工具 patch（windows 下有 cygwin）；用 ant 的 patch。

windows cygwin 的 patch：

D:\apache-solr-1.3.0>patch -p0 < SOLR-236_collapsing.patch
patching file src/test/org/apache/solr/search/TestDocSet.java
patching file src/java/org/apache/solr/search/CollapseFilter.java
patching file src/java/org/apache/solr/search/DocSet.java
patching file src/java/org/apache/solr/search/NegatedDocSet.java
patching file src/java/org/apache/solr/search/SolrIndexSearcher.java
patching file src/java/org/apache/solr/common/params/CollapseParams.java
patching file src/java/org/apache/solr/handler/component/CollapseComponent.java

ant patch，把下面的内容保存为 patch-build.xml 放到 D:\apache-solr-1.3.0 目录下：

  xml   version = “1.0″   encoding = “UTF-8″ ?>
 < project   name = “solr-patch”   default = “apply-patch”   basedir = “.” >

     < target   name = “apply-patch”   description = “Apply a patch file.  Set -Dpatch.file” >
         < patch   patchfile = “${patch.file}”   strip = “0″ />
      target >
  project >

ant 打补丁：

D:\apache-solr-1.3.0>ant -Dpatch.file=SOLR-236_collapsing.patch -f patch-build.xml
Buildfile: patch-build.xml

apply-patch:
[patch] patching file src/test/org/apache/solr/search/TestDocSet.java
[patch] patching file src/java/org/apache/solr/search/CollapseFilter.java
[patch] patching file src/java/org/apache/solr/search/DocSet.java
[patch] patching file src/java/org/apache/solr/search/NegatedDocSet.java
[patch] patching file src/java/org/apache/solr/search/SolrIndexSearcher.java
[patch] patching file src/java/org/apache/solr/common/params/CollapseParams.java
[patch] patching file src/java/org/apache/solr/handler/component/CollapseComponent.java

BUILD SUCCESSFUL
Total time: 0 seconds

源码打上了补丁，然后用 ant 构建源码：

D:\apache-solr-1.3.0>ant dist

在 D:/apache-solr-1.3.0/dist 目录下可以找到编译好的 solr 了。然后把 solr 放到 tomcat 中去运行它，把下面的内容保存在 TOMCAT_HOME/conf/Catalina/localhost/solr.xml 文件中：

 < Context   docBase = “D:\apache-solr-1.3.0\dist\apache-solr-1.3.0.war”   reloadable = “true”   >
     < Environment   name = “solr/home”   type = “java.lang.String”   value = “D:\apache-solr-1.3.0\example\solr”   override = “true”   />
  Context >

修改 D:\apache-solr-1.3.0\example\solr\conf\solrconfig.xml 使 solr 可以支持 collapse。

定义搜索组件，在 QueryComponent 附近：

 < searchComponent   name = “collapse”   class = “org.apache.solr.handler.component.CollapseComponent”   />

定义一个 handler 使用上面的搜索组件：

 < requestHandler   name = “collapse”   class = “solr.SearchHandler” >

    < lst   name = “defaults” >
      < str   name = “echoParams” > explicit  str >
     lst >
   < arr   name = “components” >
     < str > collapse  str >
     < str > debug  str >
    arr >
  requestHandler >

安装启动 tomcat，现在提交一些数据给它，用官方的示例数据就可以了。运行：

D:\apache-solr-1.3.0\example\exampledocs>java -Durl=http://localhost:8080/solr/update -Dcommit=yes -jar post.jar *.xml
SimplePostTool: version 1.2
SimplePostTool: WARNING: Make sure your XML documents are encoded in UTF-8, other encodings are not currently supported
SimplePostTool: POSTing files to http://localhost:8080/solr/update..
SimplePostTool: POSTing file hd.xml
SimplePostTool: POSTing file ipod_other.xml
SimplePostTool: POSTing file ipod_video.xml
SimplePostTool: POSTing file mem.xml
SimplePostTool: POSTing file monitor.xml
SimplePostTool: POSTing file monitor2.xml
SimplePostTool: POSTing file mp500.xml
SimplePostTool: POSTing file sd500.xml
SimplePostTool: POSTing file solr.xml
SimplePostTool: POSTing file spellchecker.xml
SimplePostTool: POSTing file utf8-example.xml
SimplePostTool: POSTing file vidcard.xml
SimplePostTool: COMMITting Solr index changes..

http://localhost:8080/solr/admin/stats.jsp   有结果了？ 有了。然后开始查询试试看。

查询：http://localhost:8080/solr/select/?q=*%3A*&indent=on&qt=collapse&collapse=true&collapse.field=popularity&collapse.threshold=1

结果：

  xml   version = “1.0″   encoding = “UTF-8″ ?>
 < response >

 < lst   name = “responseHeader” >
  < int   name = “status” > 0  int >
  < int   name = “QTime” > 0  int >
  < lst   name = “params” >
   < str   name = “collapse.field” > popularity  str >
   < str   name = “fl” > id  str >
   < str   name = “collapse.threshold” > 1  str >
   < str   name = “indent” > on  str >
   < str   name = “q” > *:*  str >
   < str   name = “qt” > collapse  str >
   < str   name = “collapse” > true  str >
   lst >
  lst >
 < lst   name = “collapse_counts” >
  < str   name = “field” > popularity  str >
  < lst   name = “doc” >
   < int   name = “SP2514N” > 4  int >
   < int   name = “F8V7067-APL-KIT” > 1  int >
   < int   name = “MA147LL/A” > 1  int >
   < int   name = “TWINX2048-3200PRO” > 1  int >
   < int   name = “VS1GB400C3″ > 3  int >
   < int   name = “1″ > 10  int >
   lst >
  < lst   name = “count” >
   < int   name = “6″ > 4  int >
   < int   name = “1″ > 1  int >
   < int   name = “10″ > 1  int >
   < int   name = “5″ > 1  int >
   < int   name = “7″ > 3  int >
   < int   name = “0″ > 10  int >
   lst >
  < str   name = “debug” > HashDocSet(6) Time(ms): 0/0/0/0  str >
  lst >
 < result   name = “response”   numFound = “6″   start = “0″ >
  < doc >
   < str   name = “id” > SP2514N  str >
   doc >
  < doc >
   < str   name = “id” > F8V7067-APL-KIT  str >
   doc >
  < doc >
   < str   name = “id” > MA147LL/A  str >
   doc >
  < doc >
   < str   name = “id” > TWINX2048-3200PRO  str >
   doc >
  < doc >
   < str   name = “id” > VS1GB400C3  str >
   doc >
  < doc >
   < str   name = “id” > 1  str >
   doc >
  result >
  response >

可以看到 collapse_counts 相关的输出：

 < lst   name = “collapse_counts” >
  < str   name = “field” > popularity  str >
  < lst   name = “doc” >
   < int   name = “SP2514N” > 4  int >
 …
   lst >
  < lst   name = “count” >
   < int   name = “6″ > 4  int >
   < int   name = “1″ > 1  int >
   < int   name = “10″ > 1  int >
   < int   name = “5″ > 1  int >
   < int   name = “7″ > 3  int >
   < int   name = “0″ > 10  int >
   lst >
  < str   name = “debug” > HashDocSet(6) Time(ms): 0/0/0/0  str >
  lst >

上面的 count 下的内容（它的顺序是result/doc的顺序），表示 popularity=6 相同的结果还有 4 个，与 popularity=1 相同的结果还有 1 个，依此类推。这样就可以显示给用户的界面里提示“相同的其它内容不有N个”。

使用的参数有：

 #启用 collapse 组件
 collapse=true
 #用那个字段来 hash 去除重量内容
 collapse.field=popularity
 #要结果中可以最多出现几个相同的文档
 collapse.threshold=1

当然还有其它参数，请看：org.apache.solr.common.params.CollapseParams 类。

原文出处：http://blog.chenlb.com/2009/04/apply-solr-collapsing-patch-remove-duplicate-result.html