com.bugull.mongo.lucene.holder.IndexSearcherHolder.java Source code

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Here is the source code for com.bugull.mongo.lucene.holder.IndexSearcherHolder.java

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/*
 * Copyright (c) www.bugull.com
 * 
 * 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 com.bugull.mongo.lucene.holder;

import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.search.IndexSearcher;

/**
 * Cache(Map) contains IndexSearcher.
 * 
 * @author Frank Wen(xbwen@hotmail.com)
 */
public class IndexSearcherHolder {

    private final static Logger logger = LogManager.getLogger(IndexSearcherHolder.class.getName());

    private final ConcurrentMap<String, IndexSearcher> map = new ConcurrentHashMap<String, IndexSearcher>();

    private static class Holder {
        final static IndexSearcherHolder instance = new IndexSearcherHolder();
    }

    public static IndexSearcherHolder getInstance() {
        return Holder.instance;
    }

    public IndexSearcher get(String name) {
        IndexSearcher searcher = map.get(name);
        if (searcher != null) {
            return searcher;
        }

        synchronized (this) {
            searcher = map.get(name);
            if (searcher == null) {
                IndexWriter writer = IndexWriterHolder.getInstance().get(name);
                IndexReader reader = null;
                try {
                    reader = IndexReader.open(writer, true);
                } catch (CorruptIndexException ex) {
                    logger.error("Something is wrong when open lucene IndexWriter", ex);
                } catch (IOException ex) {
                    logger.error("Something is wrong when open lucene IndexWriter", ex);
                }
                searcher = new IndexSearcher(reader);
                map.put(name, searcher);
            }
        }
        return searcher;
    }

    public Map<String, IndexSearcher> getAll() {
        return map;
    }

    public void put(String name, IndexSearcher searcher) {
        map.put(name, searcher);
    }

}