/*
* Copyright 2008-2011 Grant Ingersoll, Thomas Morton and Drew Farris
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* -------------------
* To purchase or learn more about Taming Text, by Grant Ingersoll, Thomas Morton and Drew Farris, visit
* http://www.manning.com/ingersoll
*/
package com.tamingtext.qa;
import java.io.IOException;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import opennlp.tools.cmdline.parser.ParserTool;
import opennlp.tools.parser.Parse;
import opennlp.tools.parser.Parser;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.index.Term;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.spans.SpanNearQuery;
import org.apache.lucene.search.spans.SpanQuery;
import org.apache.lucene.search.spans.SpanTermQuery;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.SolrException.ErrorCode;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.schema.SchemaField;
import org.apache.solr.search.QParser;
/**
* The QuestionQParser takes in a natural language question and produces a Lucene {@link org.apache.lucene.search.spans.SpanNearQuery}
*
*/
public class QuestionQParser extends QParser implements QAParams {
private Parser parser;
private AnswerTypeClassifier atc;
private Map<String,String> atm;
public QuestionQParser(String qstr, SolrParams localParams, SolrParams params, SolrQueryRequest req,
Parser parser, AnswerTypeClassifier atc,
Map<String,String> answerTypeMap) {
super(qstr, localParams, params, req);
this.parser = parser;
this.atc = atc;
this.atm = answerTypeMap;
}
@Override
public Query parse() throws ParseException {
//<start id="qqp.parse"/>
Parse parse = ParserTool.parseLine(qstr, parser, 1)[0];//<co id="qqp.parseLine"/>
/*
<calloutlist>
<callout arearefs="qqp.parseLine"><para>Parse the question using the <classname>TreebankParser</classname>. The resulting <classname>Parse</classname> object can then be utilized by the classifier to determine the Answer Type.</para></callout>
</calloutlist>
*/
//<end id="qqp.parse"/>
//<start id="qqp.answerType"/>
String type = atc.computeAnswerType(parse);
String mt = atm.get(type);
//<end id="qqp.answerType"/>
String field = params.get(QUERY_FIELD);
SchemaField sp = req.getSchema().getFieldOrNull(field);
if (sp == null) {
throw new SolrException(ErrorCode.SERVER_ERROR,"Undefined field: "+field);
}
//<start id="qqp.query"/>
List<SpanQuery> sql = new ArrayList<SpanQuery>();
if (mt != null) {//<co id="qqp.handleAT"/>
String[] parts = mt.split("\\|");
if (parts.length == 1) {
sql.add(new SpanTermQuery(new Term(field, mt.toLowerCase())));
} else {
for (int pi = 0; pi < parts.length; pi++) {
sql.add(new SpanTermQuery(new Term(field, parts[pi])));
}
}
}
try {
Analyzer analyzer = sp.getType().getQueryAnalyzer();
TokenStream ts = analyzer.tokenStream(field,
new StringReader(qstr));
while (ts.incrementToken()) {//<co id="qqp.addTerms"/>
String term = ((CharTermAttribute)
ts.getAttribute(CharTermAttribute.class)).toString();
sql.add(new SpanTermQuery(new Term(field, term)));
}
} catch (IOException e) {
throw new ParseException(e.getLocalizedMessage());
}
return new SpanNearQuery(sql.toArray(new SpanQuery[sql.size()]), params.getInt(QAParams.SLOP, 10), true);//<co id="qqp.spanNear"/>
/*
<calloutlist>
<callout arearefs="qqp.handleAT"><para>Add the AnswerType to the query</para></callout>
<callout arearefs="qqp.addTerms"><para>Add the original query terms to the query</para></callout>
<callout arearefs="qqp.spanNear"><para>Query the index looking for all of the parts near each other</para></callout>
</calloutlist>
*/
//<end id="qqp.query"/>
}
}