QueryResponseWriter
A QueryResponseWriter is a Solr Plugin that defines the response format for any request.
Configuration
Multiple writers (including multiple instances of the same QueryResponseWriter class with different configurations) can be specified in the solrconfig.xml
<queryResponseWriter name="foo" default="true" class="my.package.CustomResponseWriter"/> <queryResponseWriter name="bar" class="my.package.AnotherCustomResponseWriter"/> <queryResponseWriter name="blat" class="my.package.AnotherCustomResponseWriter"> <int name="some_init_param">5</int> </queryResponseWriter>
Response Writer Resolution
Clients access specific QueryResponseWriters using the 'wt' parameter For the above example, running on localhost:8983/solr/, you could access:
http://localhost:8983/solr/select/?wt=foo&q=solr http://localhost:8983/solr/select/?wt=bar&q=solr http://localhost:8983/solr/select/?wt=blat&q=solr http://localhost:8983/solr/select/?q=solr
Solr selects a handler to process a request using the following steps...
- look for a writer with a name matching the "wt"
- look for a writer configured with
default="true"
- look for a writer configured with name="standard"
- use an anonymous instance of XmlResponseWriter
List of Writers Available
The Javadocs contain a complete list of Response Writers. Many of which have their own wiki pages...