package org.apache.solr.spelling;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.store.FSDirectory;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.core.SolrCore;
import org.apache.solr.search.SolrIndexSearcher;
import org.apache.lucene.search.spell.HighFrequencyDictionary;
import java.io.File;
import java.io.IOException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* <p>
* A spell checker implementation that loads words from Solr as well as arbitary Lucene indices.
* </p>
*
* <p>
* Refer to <a href="http://wiki.apache.org/solr/SpellCheckComponent">SpellCheckComponent</a>
* for more details.
* </p>
*
* @since solr 1.3
**/
public class IndexBasedSpellChecker extends AbstractLuceneSpellChecker {
private static final Logger log = LoggerFactory.getLogger(IndexBasedSpellChecker.class);
public static final String THRESHOLD_TOKEN_FREQUENCY = "thresholdTokenFrequency";
protected float threshold;
protected IndexReader reader;
@Override
public String init(NamedList config, SolrCore core) {
super.init(config, core);
threshold = config.get(THRESHOLD_TOKEN_FREQUENCY) == null ? 0.0f
: (Float) config.get(THRESHOLD_TOKEN_FREQUENCY);
initSourceReader();
return name;
}
private void initSourceReader() {
if (sourceLocation != null) {
try {
FSDirectory luceneIndexDir = FSDirectory.open(new File(sourceLocation));
this.reader = IndexReader.open(luceneIndexDir);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
@Override
public void build(SolrCore core, SolrIndexSearcher searcher) {
IndexReader reader = null;
try {
if (sourceLocation == null) {
// Load from Solr's index
reader = searcher.getReader();
} else {
// Load from Lucene index at given sourceLocation
reader = this.reader;
}
// Create the dictionary
dictionary = new HighFrequencyDictionary(reader, field,
threshold);
spellChecker.clearIndex();
spellChecker.indexDictionary(dictionary, new IndexWriterConfig(core.getSolrConfig().luceneMatchVersion, null), false);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
@Override
protected IndexReader determineReader(IndexReader reader) {
IndexReader result = null;
if (sourceLocation != null) {
result = this.reader;
} else {
result = reader;
}
return result;
}
@Override
public void reload(SolrCore core, SolrIndexSearcher searcher) throws IOException {
super.reload(core, searcher);
//reload the source
initSourceReader();
}
public float getThreshold() {
return threshold;
}
}