[JRuby][Solr] BinaryResponseWriterで書き出したものをRackサーバーで返す

response_writer_wrapper.rb

java_import Java::java.io.ByteArrayOutputStream
java_import Java::java.io.OutputStreamWriter
java_import Java::java.util.HashMap
java_import Java::org.apache.solr.common.SolrDocument
java_import Java::org.apache.solr.common.SolrDocumentList
java_import Java::org.apache.solr.common.params.SolrParams
java_import Java::org.apache.solr.common.util.NamedList
java_import Java::org.apache.solr.request.SolrQueryRequestBase
java_import Java::org.apache.solr.response.SolrQueryResponse
java_import Java::org.apache.solr.response.XMLResponseWriter
java_import Java::org.apache.solr.response.BinaryResponseWriter

module Solr
  class ResponseWriterWrapper
    # Abstractなクラスを継承
    class MySolrQueryRequest < SolrQueryRequestBase; end
    class MySolrParams < SolrParams
      def get param
        nil
      end
      def getParams param
        []
      end
      def getParameterNamesIterator
        HashMap.new.keySet.iterator
      end
    end

    # SolrQueryRequest
    def request
      MySolrQueryRequest.new nil, MySolrParams.new
    end

    # SolrQueryResponse
    def response data
      docList = SolrDocumentList.new
      data.each {|d|
        doc = SolrDocument.new
        d.each {|k,v| doc.setField k, v }
        docList.add doc
      }
      docList.setNumFound data.size
      docList.setStart 0
      docList.setMaxScore 1.0
      res = SolrQueryResponse.new
      res.add "response", docList
      res
    end

    def responseWriter
      BinaryResponseWriter.new
    end

    def write data
      outputStream = ByteArrayOutputStream.new
      responseWriter.write outputStream, request, response(data)
      byteArray = outputStream.toByteArray
      String.from_java_bytes byteArray
    end
  end
end

server.rb

require "webrick"
require "yaml"
require "./solr/response_writer_wrapper"

server = WEBrick::HTTPServer.new(
  Port: 8080,
  Logger: WEBrick::Log.new('/dev/null'),
  AccessLog: []
)
server.mount_proc("/") {|req, res|
  res["Content-Type"] = "application/octet-stream"
  data = YAML.load <<EOM
- poi_code: G0123456789
  category1_code:
    - M01
EOM
  puts data
  res.body = Solr::ResponseWriterWrapper.new.write data
}
server.start