/** * 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.hadoop.contrib.dlucene;import java.io.IOException;import org.apache.lucene.analysis.Analyzer;import org.apache.lucene.analysis.standard.StandardAnalyzer;import org.apache.lucene.document.Document;import org.apache.lucene.document.Field;import org.apache.lucene.index.IndexWriter;import org.apache.lucene.queryParser.ParseException;import org.apache.lucene.queryParser.QueryParser;import org.apache.lucene.search.Hits;import org.apache.lucene.search.IndexSearcher;import org.apache.lucene.search.Query;import org.apache.lucene.store.RAMDirectory;public class LuceneIndex {  RAMDirectory rd = null;    private Document createDocument(String author, String title, String topic) {    Document document = new Document();    document.add(new Field("author", author, Field.Store.YES,        Field.Index.TOKENIZED));    document.add(new Field("title", title, Field.Store.YES,        Field.Index.TOKENIZED));    document.add(new Field("topic", topic, Field.Store.YES,        Field.Index.TOKENIZED));    return document;  }  public LuceneIndex() throws IOException {    rd = new RAMDirectory();    Analyzer analyzer = new StandardAnalyzer();    IndexWriter writer = new IndexWriter(rd, analyzer, true);    writer.close();  }  private void indexDocument(Document document) throws Exception {    Analyzer analyzer = new StandardAnalyzer();    IndexWriter writer = new IndexWriter(rd, analyzer, false);    writer.addDocument(document);    writer.optimize();    writer.close();  }  public void indexArticle(String author, String title, String topic)      throws Exception {    Document document = createDocument(author, title, topic);    indexDocument(document);  }  public Hits search(String searchCriteria) throws IOException, ParseException {    IndexSearcher is = new IndexSearcher(rd);    Analyzer analyzer = new StandardAnalyzer();    QueryParser parser = new QueryParser("article", analyzer);    Query query = parser.parse(searchCriteria);    Hits hits = is.search(query);    return hits;  }}