/**
* 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.
*/
package org.apache.solr.spelling;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.lucene.analysis.WhitespaceAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.spell.PlainTextDictionary;
import org.apache.lucene.store.RAMDirectory;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.core.SolrCore;
import org.apache.solr.core.SolrResourceLoader;
import org.apache.solr.schema.FieldType;
import org.apache.solr.schema.IndexSchema;
import org.apache.solr.util.HighFrequencyDictionary;
import org.apache.solr.search.SolrIndexSearcher;
/**
* <p>
* A spell checker implementation that loads words from a text file (one word per line).
* </p>
*
* @since solr 1.3
**/
public class FileBasedSpellChecker extends AbstractLuceneSpellChecker {
private static final Logger log = Logger.getLogger(FileBasedSpellChecker.class.getName());
public static final String SOURCE_FILE_CHAR_ENCODING = "characterEncoding";
private String characterEncoding;
public static final String WORD_FIELD_NAME = "word";
public String init(NamedList config, SolrCore core) {
super.init(config, core);
characterEncoding = (String) config.get(SOURCE_FILE_CHAR_ENCODING);
return name;
}
public void build(SolrCore core, SolrIndexSearcher searcher) {
try {
loadExternalFileDictionary(core.getSchema(), core.getResourceLoader());
spellChecker.clearIndex();
spellChecker.indexDictionary(dictionary);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
/**
* Override to return null, since there is no reader associated with a file based index
*/
@Override
protected IndexReader determineReader(IndexReader reader) {
return null;
}
@SuppressWarnings("unchecked")
private void loadExternalFileDictionary(IndexSchema schema, SolrResourceLoader loader) {
IndexSearcher searcher = null;
try {
// Get the field's analyzer
if (fieldTypeName != null
&& schema.getFieldTypeNoEx(fieldTypeName) != null) {
FieldType fieldType = schema.getFieldTypes()
.get(fieldTypeName);
// Do index-time analysis using the given fieldType's analyzer
RAMDirectory ramDir = new RAMDirectory();
IndexWriter writer = new IndexWriter(ramDir, fieldType.getAnalyzer(),
true, IndexWriter.MaxFieldLength.UNLIMITED);
writer.setMergeFactor(300);
writer.setMaxBufferedDocs(150);
List<String> lines = loader.getLines(sourceLocation, characterEncoding);
for (String s : lines) {
Document d = new Document();
d.add(new Field(WORD_FIELD_NAME, s, Field.Store.NO, Field.Index.TOKENIZED));
writer.addDocument(d);
}
writer.optimize();
writer.close();
dictionary = new HighFrequencyDictionary(IndexReader.open(ramDir),
WORD_FIELD_NAME, 0.0f);
} else {
// check if character encoding is defined
if (characterEncoding == null) {
dictionary = new PlainTextDictionary(loader.openResource(sourceLocation));
} else {
dictionary = new PlainTextDictionary(new InputStreamReader(loader.openResource(sourceLocation), characterEncoding));
}
}
} catch (IOException e) {
log.log(Level.SEVERE, "Unable to load spellings", e);
} finally {
try {
if (searcher != null)
searcher.close();
} catch (IOException e) {
// Ignore
}
}
}
public String getCharacterEncoding() {
return characterEncoding;
}
}