/**
* wiki-tools-lucene: Java package for searching Wikipedia dumps with Lucene
*
* 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.
*/
package cc.wikitools.lucene;
import java.io.File;
import java.io.IOException;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.NumericRangeQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.search.similarities.Similarity;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.search.similarities.LMDirichletSimilarityFactory;
import cc.wikitools.lucene.IndexWikipediaDump.IndexField;
import com.google.common.base.Preconditions;
public class WikipediaSearcher {
private IndexReader reader;
private IndexSearcher searcher;
private QueryParser parserArticle;
private QueryParser parserTitle;
public WikipediaSearcher(File indexLocation) throws IOException {
Preconditions.checkNotNull(indexLocation);
Preconditions.checkArgument(indexLocation.exists());
reader = DirectoryReader.open(FSDirectory.open(indexLocation));
searcher = new IndexSearcher(reader);
NamedList<Double> paramNamedList = new NamedList<Double>();
paramNamedList.add("mu", 2500.0);
SolrParams params = SolrParams.toSolrParams(paramNamedList);
LMDirichletSimilarityFactory factory = new LMDirichletSimilarityFactory();
factory.init(params);
Similarity simLMDir = factory.getSimilarity();
searcher.setSimilarity(simLMDir);
parserArticle = new QueryParser(Version.LUCENE_43, IndexField.TEXT.name, IndexWikipediaDump.ANALYZER);
parserTitle = new QueryParser(Version.LUCENE_43, IndexField.TITLE.name, IndexWikipediaDump.ANALYZER);
}
public TopDocs searchArticle(String q, int numResults) {
try {
Query query = parserArticle.parse(q);
return searcher.search(query, numResults);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public TopDocs searchTitle(String q, int numResults) {
try {
Query query = parserTitle.parse(q);
return searcher.search(query, numResults);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public Document doc(int docid) {
try {
return searcher.doc(docid);
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
public Document getArticle(int id) {
try {
Query query = NumericRangeQuery.newIntRange(IndexField.ID.name, id, id, true, true);
TopDocs rs = searcher.search(query, 1);
if (rs.totalHits == 0) {
return null;
}
ScoreDoc scoreDoc = rs.scoreDocs[0];
Document hit = searcher.doc(scoreDoc.doc);
return hit;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
public void close() {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}