/**
* Copyright 2014 National University of Ireland, Galway.
*
* This file is part of the SIREn project. Project and contact information:
*
* https://github.com/rdelbru/SIREn
*
* 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 org.sindice.siren.demo;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.core.WhitespaceAnalyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.queryparser.flexible.core.QueryNodeException;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.SearcherManager;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;
import org.sindice.siren.qparser.json.JsonQueryParser;
import org.sindice.siren.qparser.keyword.KeywordQueryParser;
import org.sindice.siren.util.JSONDatatype;
import org.sindice.siren.util.XSDDatatype;
/**
* This class shows how to use the SIREn's parsers to search over JSON data.
* <p>
* There is no specific configuration required for searching over fields indexed
* with the SIREn's posting format.
*/
public class SimpleSearcher {
private final Directory dir;
private final SearcherManager mgr;
public SimpleSearcher(final File path) throws IOException {
dir = FSDirectory.open(path);
mgr = new SearcherManager(dir, null);
}
public void close() throws IOException {
mgr.close();
dir.close();
}
public String[] search(final Query q, final int n) throws IOException {
IndexSearcher searcher = mgr.acquire();
try {
final ScoreDoc[] results = searcher.search(q, null, n).scoreDocs;
final String[] ids = new String[results.length];
for (int i = 0; i < results.length; i++) {
ids[i] = this.retrieve(results[i].doc).get(SimpleIndexer.DEFAULT_ID_FIELD);
}
return ids;
}
finally {
mgr.release(searcher);
searcher = null;
}
}
public Document retrieve(final int docID) throws IOException {
IndexSearcher searcher = mgr.acquire();
try {
return searcher.doc(docID);
}
finally {
mgr.release(searcher);
searcher = null;
}
}
public Query parseKeywordQuery(final String keywordQuery) throws QueryNodeException {
final KeywordQueryParser parser = new KeywordQueryParser();
parser.setDatatypeAnalyzers(this.getDatatypeAnalyzers());
return parser.parse(keywordQuery, SimpleIndexer.DEFAULT_SIREN_FIELD);
}
public Query parseJsonQuery(final String JsonQuery) throws QueryNodeException {
final JsonQueryParser parser = new JsonQueryParser();
final KeywordQueryParser kParser = new KeywordQueryParser();
kParser.setDatatypeAnalyzers(this.getDatatypeAnalyzers());
kParser.setAllowTwig(false);
parser.setKeywordQueryParser(kParser);
return parser.parse(JsonQuery, SimpleIndexer.DEFAULT_SIREN_FIELD);
}
private Map<String, Analyzer> getDatatypeAnalyzers() {
final Map<String, Analyzer> analyzers = new HashMap<String, Analyzer>();
analyzers.put(XSDDatatype.XSD_STRING, new StandardAnalyzer(Version.LUCENE_40));
analyzers.put(JSONDatatype.JSON_FIELD, new WhitespaceAnalyzer(Version.LUCENE_40));
return analyzers;
}
}