IndexSearcherCache.java

/*
 * 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 net.tooan.ynpay.third.mongodb.cache;

import net.tooan.ynpay.third.jfinal.log.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;

import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

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

    private final static Logger logger = Logger.getLogger(IndexSearcherCache.class);

    private static IndexSearcherCache instance = new IndexSearcherCache();

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

    private IndexSearcherCache() {

    }

    public static IndexSearcherCache getInstance() {
        return instance;
    }

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

        synchronized (this) {
            searcher = cache.get(name);
            if (searcher == null) {
                IndexWriter writer = IndexWriterCache.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);
                cache.put(name, searcher);
            }
        }
        return searcher;
    }

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

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

}