org.cee.store.lucene.LuceneStoreBase.java Source code

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Here is the source code for org.cee.store.lucene.LuceneStoreBase.java

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package org.cee.store.lucene;

/*
 * #%L
 * Content Extraction Engine - News Store Lucene
 * %%
 * Copyright (C) 2013 Andreas Behnke
 * %%
 * 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.
 * #L%
 */

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexableField;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.SearcherManager;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.TopDocs;
import org.cee.store.EntityKey;

import com.google.gson.Gson;

public abstract class LuceneStoreBase {

    protected static final Gson GSON = new Gson();

    private IndexWriter indexWriter;

    private SearcherManager searcherManager;

    private Object searcherManagerLock = new Object();

    private LuceneAnalyzers analyzers;

    private SearcherManager getSearcherManager() throws IOException {
        if (searcherManager == null) {
            synchronized (searcherManagerLock) {
                if (searcherManager == null) {
                    searcherManager = new SearcherManager(indexWriter, false, null);
                }
            }
        }
        return searcherManager;
    }

    protected IndexSearcher aquireSearcher() throws IOException {
        return getSearcherManager().acquire();
    }

    protected void releaseSearcher(IndexSearcher searcher) throws IOException {
        getSearcherManager().release(searcher);
    }

    protected String getStringFieldOrNull(Document document, String fieldName) {
        IndexableField field = document.getField(fieldName);
        if (field == null) {
            return null;
        } else {
            return field.stringValue();
        }
    }

    public IndexWriter getIndexWriter() {
        return indexWriter;
    }

    public void setIndexWriter(IndexWriter indexWriter) {
        this.indexWriter = indexWriter;
    }

    public LuceneAnalyzers getAnalyzers() {
        return analyzers;
    }

    public void setAnalyzers(LuceneAnalyzers analysers) {
        this.analyzers = analysers;
    }

    protected Document getSingleDocument(IndexSearcher searcher, Query query) throws IOException {
        TopDocs topDocs = searcher.search(query, 1);
        if (topDocs.totalHits == 0) {
            return null;
        } else {
            return searcher.doc(topDocs.scoreDocs[0].doc);
        }
    }

    protected boolean containsDocument(Query query, IndexSearcher searcher) throws IOException {
        TopDocs topDocs = searcher.search(query, 1);
        if (topDocs.totalHits == 0) {
            return false;
        } else {
            return true;
        }
    }

    protected boolean containsDocument(Query query) throws IOException {
        IndexSearcher searcher = aquireSearcher();
        try {
            return containsDocument(query, searcher);
        } finally {
            releaseSearcher(searcher);
        }
    }

    protected long documentCount(Query query) throws IOException {
        IndexSearcher searcher = aquireSearcher();
        try {
            TopDocs topDocs = searcher.search(query, LuceneConstants.MAX_RESULT_SIZE);
            return topDocs.totalHits;
        } finally {
            releaseSearcher(searcher);
        }
    }

    protected List<EntityKey> getSortedDocuments(Query query, Sort sort, String keyField, String nameField)
            throws IOException {
        List<EntityKey> entityKeys = new ArrayList<EntityKey>();
        IndexSearcher searcher = aquireSearcher();
        try {
            TopDocs topDocs = searcher.search(query, LuceneConstants.MAX_RESULT_SIZE, sort);
            for (ScoreDoc scoreDoc : topDocs.scoreDocs) {
                Document doc = searcher.doc(scoreDoc.doc);
                String key = doc.get(keyField);
                String name = doc.get(nameField);
                entityKeys.add(EntityKey.get(key, name));
            }
        } finally {
            releaseSearcher(searcher);
        }
        return entityKeys;
    }

    protected Analyzer getAnalyzer(String language) {
        return analyzers.getAnalayserForLanguage(language);
    }

    protected void deleteDocuments(Query query) throws IOException {
        indexWriter.deleteDocuments(query);
    }

    protected void addDocument(Document document, String language) throws IOException {
        Analyzer analyzer = analyzers.getAnalayserForLanguage(language);
        indexWriter.addDocument(document, analyzer);
    }

    protected void commit() throws IOException {
        indexWriter.commit();
        getSearcherManager().maybeRefreshBlocking();
    }
}