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...

  1. look for a writer with a name matching the "wt"
  2. look for a writer configured with default="true"
  3. look for a writer configured with name="standard"
  4. 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...

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