solr-8 RequestHandlers and SearchComponents in SolrConfig

solr中通过url实现的每个request(包括查询和索引)都需要对应一个request handle,这里定义了请求对应的类和默认参数等
url请求路径为host/solr/collectionname/requestname
而每一个search都需要一个searchcomponents来驱动
默认的search components如下
query solr.QueryComponent Described in the section Query Syntax and Parsing
facet solr.FacetComponent Described in the section Faceting.
mlt solr.MoreLikeThisComponent Described in the section MoreLikeThis.
highlight solr.HighlightComponent Described in the section Highlighting.
stats solr.StatsComponent Described in the section The Stats Component.
debug solr.DebugComponent Described in the section on Common Query Parameters
expand solr.ExpandComponent Described in the section Collapse and Expand Results.