com.buddycloud.channeldirectory.search.handler.metadata.MetadataQueryHandler.java Source code

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Here is the source code for com.buddycloud.channeldirectory.search.handler.metadata.MetadataQueryHandler.java

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/*
 * Copyright 2011 buddycloud
 *
 * 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.buddycloud.channeldirectory.search.handler.metadata;

import java.net.MalformedURLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import org.apache.solr.client.solrj.SolrQuery;
import org.apache.solr.client.solrj.SolrServer;
import org.apache.solr.client.solrj.SolrServerException;
import org.apache.solr.client.solrj.response.QueryResponse;
import org.apache.solr.common.SolrDocument;
import org.apache.solr.common.SolrDocumentList;
import org.dom4j.Element;
import org.xmpp.packet.IQ;

import com.buddycloud.channeldirectory.commons.solr.SolrServerFactory;
import com.buddycloud.channeldirectory.commons.solr.SolrUtils;
import com.buddycloud.channeldirectory.search.handler.common.ChannelQueryHandler;
import com.buddycloud.channeldirectory.search.handler.response.ChannelData;
import com.buddycloud.channeldirectory.search.rsm.RSM;
import com.buddycloud.channeldirectory.search.rsm.RSMUtils;
import com.buddycloud.channeldirectory.search.rsm.SolrRSMUtils;
import com.buddycloud.channeldirectory.search.utils.XMPPUtils;

/**
 * Handles queries for content metadata.
 * A query should contain a metadata query string, so
 * this handle can return channels related to this search.
 *  
 */
public class MetadataQueryHandler extends ChannelQueryHandler {

    public MetadataQueryHandler(Properties properties) {
        super("http://buddycloud.com/channel_directory/metadata_query", properties);
    }

    @Override
    public IQ handle(IQ iq) {

        Element queryElement = iq.getElement().element("query");
        Element searchElement = queryElement.element("search");

        if (searchElement == null) {
            return XMPPUtils.error(iq, "Query does not contain search element.", getLogger());
        }

        String search = searchElement.getText();

        if (search == null || search.isEmpty()) {
            return XMPPUtils.error(iq, "Search content cannot be empty.", getLogger());
        }

        RSM rsm = RSMUtils.parseRSM(queryElement);

        List<ChannelData> channelObjects;
        try {
            channelObjects = findObjectsByMetadata(rsm, search);
        } catch (Exception e) {
            return XMPPUtils.error(iq, "Search could not be performed, service is unavailable.", getLogger());
        }

        return createIQResponse(iq, channelObjects, rsm);
    }

    private List<ChannelData> findObjectsByMetadata(RSM rsm, String search)
            throws MalformedURLException, SolrServerException {
        SolrServer solrServer = SolrServerFactory.createChannelCore(getProperties());
        SolrQuery solrQuery = new SolrQuery(search);

        SolrRSMUtils.preprocess(solrQuery, rsm);
        QueryResponse queryResponse = solrServer.query(solrQuery);
        SolrRSMUtils.postprocess(queryResponse, rsm);

        return convertResponse(queryResponse);
    }

    private static List<ChannelData> convertResponse(QueryResponse queryResponse) {
        List<ChannelData> channels = new ArrayList<ChannelData>();
        SolrDocumentList results = queryResponse.getResults();

        for (SolrDocument solrDocument : results) {
            channels.add(SolrUtils.convertToChannelData(solrDocument));
        }

        return channels;
    }
}