edu.ur.ir.groupspace.service.DefaultGroupWorkspaceSearchService.java Source code

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Here is the source code for edu.ur.ir.groupspace.service.DefaultGroupWorkspaceSearchService.java

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/**  
   Copyright 2008 - 2012 University of Rochester
    
   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 edu.ur.ir.groupspace.service;

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

import org.apache.log4j.Logger;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.queryParser.MultiFieldQueryParser;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.NumericUtils;
import org.apache.lucene.util.Version;

import edu.ur.ir.SearchHelper;
import edu.ur.ir.SearchResults;
import edu.ur.ir.groupspace.GroupWorkspace;
import edu.ur.ir.groupspace.GroupWorkspaceSearchService;
import edu.ur.ir.groupspace.GroupWorkspaceService;

/**
 * Default implementation for the gorup workspace search service.
 * 
 * @author Nathan Sarr
 *
 */
public class DefaultGroupWorkspaceSearchService implements GroupWorkspaceSearchService {

    // eclipse generated id
    private static final long serialVersionUID = -7867033472526750057L;

    // File system service for loading file system objects 
    private GroupWorkspaceService groupWorkspaceService;

    // Fields to be searched   
    private String[] fields = { DefaultGroupWorkspaceIndexService.GROUP_NAME,
            DefaultGroupWorkspaceIndexService.GROUP_DESCRIPTION };

    // Analyzer for dealing with analyzing the search 
    private transient Analyzer analyzer;

    //  Get the logger for this class 
    private static final Logger log = Logger.getLogger(DefaultGroupWorkspaceSearchService.class);

    public SearchResults<GroupWorkspace> search(File indexFolder, String query, int offset, int numResults) {
        SearchResults<GroupWorkspace> searchResults = new SearchResults<GroupWorkspace>();
        searchResults.setOriginalQuery(query);
        query = SearchHelper.prepareMainSearchString(query, true);
        ArrayList<GroupWorkspace> groupWorkspaces = new ArrayList<GroupWorkspace>();
        if (log.isDebugEnabled()) {
            log.debug(
                    "User search results executing query " + query + " on index " + indexFolder.getAbsolutePath());
        }

        IndexSearcher searcher = null;
        IndexReader reader = null;
        try {
            FSDirectory directory = FSDirectory.open(indexFolder);
            reader = IndexReader.open(directory, true);
            searcher = new IndexSearcher(reader);
            QueryParser parser = new MultiFieldQueryParser(Version.LUCENE_35, fields, analyzer);
            parser.setDefaultOperator(QueryParser.AND_OPERATOR);

            Query luceneQuery = parser.parse(query);
            TopDocs hits = searcher.search(luceneQuery, 1000);
            searchResults.setTotalHits(hits.totalHits);

            int position = offset;
            int addedResults = 0;
            while (hits.totalHits > position && (addedResults < numResults)) {
                if (log.isDebugEnabled()) {
                    log.debug(" adding document at position " + position);

                }

                Document d = searcher.doc(hits.scoreDocs[position].doc);
                Long groupWorkspaceId = NumericUtils.prefixCodedToLong(d.get(DefaultGroupWorkspaceIndexService.ID));
                log.debug("group workspace id = " + groupWorkspaceId);
                GroupWorkspace groupWorkspace = groupWorkspaceService.get(groupWorkspaceId, false);
                groupWorkspaces.add(groupWorkspace);
                addedResults += 1;
                position += 1;
            }
        } catch (Exception e) {
            log.error(e);
        } finally {
            if (searcher != null) {
                try {
                    searcher.close();
                } catch (IOException e) {
                    log.error("the searcher could not be closed", e);
                }
            }
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    log.error("the reader could not be closed", e);
                }
            }
        }
        searchResults.setObjects(groupWorkspaces);
        return searchResults;
    }

    /**
     * Set the group workspace service.
     * 
     * @param groupWorkspaceService
     */
    public void setGroupWorkspaceService(GroupWorkspaceService groupWorkspaceService) {
        this.groupWorkspaceService = groupWorkspaceService;
    }

    /**
     * Set the analyzer for searching the index.
     * 
     * @param analyzer
     */
    public void setAnalyzer(Analyzer analyzer) {
        this.analyzer = analyzer;
    }

}