Field collapsing classloading issues

[karan singh]

I applied the SOLR field collapsing patch to solr 3.1.0.                        
                                                                                
I'm not really sure about what to add in solrconfig.xml. Right now I've added 
the following :                                        <searchComponent 
name="queryComponent" class="solr.CollapseComponent" />                         
                                  <requestHandler name="hand" 
class="solr.SearchHandler" startup="lazy">                          <lst 
name="defaults">                                                   <bool 
name="ha">true</bool>                     </lst>                                
                  <arr name="components">                                 
<str>queryComponent</str>                       </arr>                      
</requestHandler>                                          On running this, I 
get the following error :                                  SEVERE: 
org.apache.solr.common.SolrException: Error loading class 
'solr.CollapseComponent'                                    Any ideas?