LuceneBasicQueryEnvelope.java :  » Content-Management-System » hippo » org » apache » slide » search » basic » Java Open Source

/*
 * $Header$
 * $Revision: 1749 $
 * $Date: 2006-04-04 08:41:40 -0700 $
 *
 * ====================================================================
 *
 * Copyright 1999-2002 The Apache Software Foundation 
 *
 * 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 org.apache.slide.search.basic;

import java.util.Iterator;

import org.apache.slide.common.Namespace;
import org.apache.slide.common.Scope;
import org.apache.slide.common.ServiceAccessException;
import org.apache.slide.common.SlideRuntimeException;
import org.apache.slide.search.InvalidScopeException;
import org.apache.slide.search.LuceneSearchQueryResult;
import org.apache.slide.search.QueryScope;
import org.apache.slide.search.SearchQueryResult;
import org.apache.slide.search.SearchToken;


/**
 * Envelopes all queries that are necessary, if a scope covers several stores.
 * For example: /mycoll is mapped to an SQL store, /mycoll/xml is mapped to an
 * XML database. A query with scope /mycoll must be divided in two different
 * queries, the result must be joined.
 *
 * @version $Revision: 1749 $
 *
 **/
public class LuceneBasicQueryEnvelope extends BasicQueryEnvelope {
    
    
    
    /*
     * Constructs a LuceneBasicQueryEnvelope
     *
     * @param token  the searchtoken
     * @param queryScope  the scope of this query
     *
     * @throws   InvalidScopeException
     */
    public LuceneBasicQueryEnvelope (SearchToken token, QueryScope[] queryScope)
        throws InvalidScopeException
    {
        super(token,queryScope);
    }
    

    
    /**
     * Executes each involved query and merges the results
     *
     * @return   a SearchQueryResult
     *
     * @throws   ServiceAccessException
     *
     */
    public SearchQueryResult execute() throws ServiceAccessException {
      
        Iterator it = subQueries.keySet().iterator();
        SearchQueryResult result = null;
        
        if (topLevelQuery.orderBy != null) {
            result = new LuceneSearchQueryResult (topLevelQuery.orderBy.getComparator());
        }
        else {
            result = new LuceneSearchQueryResult ();
        }
        
        
        
        while (it.hasNext()) {
            Scope scope = (Scope)it.next();
            
            BasicQuery query = (BasicQuery)subQueries.get (scope);
            query.setScope (calculateSubQueryScope(scope));
            
            SearchQueryResult subResult = query.execute();
            
            result.add (subResult);
            if (subResult.getStatus() != 0) {
                result.setStatus (subResult.getStatus());
                result.setDescription (subResult.getDescription());
            }
        }
        
        return result;
    }
    
    /**
     * creates a subquery
     *
     * @param    namespace           a  Namespace
     * @param    slideScope          a  String
     * @param    token               a  SearchToken
     *
     * @return   a BasicQueryImpl
     *
     * @throws   SlideRuntimeException
     *
     */
    protected BasicQueryImpl createSubQuery (Namespace namespace,
                                           String slideScope,
                                           SearchToken token)
        throws SlideRuntimeException
    {
        BasicQueryImpl q = super.createSubQuery(namespace,slideScope,token);
        
        return q;
    }
    
}