org.apache.shindig.social.websockbackend.spi.cypher.WsCypherGroupSPI.java Source code

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/*
 *  Copyright 2015 Institute of Information Systems, Hof University
 *
 *  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.
 *  under the License.
 */
package org.apache.shindig.social.websockbackend.spi.cypher;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.Future;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.servlet.http.HttpServletResponse;

import org.apache.shindig.auth.SecurityToken;
import org.apache.shindig.protocol.ProtocolException;
import org.apache.shindig.protocol.RestfulCollection;
import org.apache.shindig.social.opensocial.model.Group;
import org.apache.shindig.social.opensocial.spi.CollectionOptions;
import org.apache.shindig.social.opensocial.spi.GroupService;
import org.apache.shindig.social.opensocial.spi.UserId;
import org.apache.shindig.social.websockbackend.Constants;
import org.apache.shindig.social.websockbackend.model.dto.GroupDTO;
import org.apache.shindig.social.websockbackend.util.CollOptsConverter;

import com.google.common.util.concurrent.Futures;
import com.google.inject.Inject;
import com.google.inject.Singleton;

import de.hofuniversity.iisys.neo4j.websock.queries.IQueryCallback;
import de.hofuniversity.iisys.neo4j.websock.queries.IQueryHandler;
import de.hofuniversity.iisys.neo4j.websock.query.EQueryType;
import de.hofuniversity.iisys.neo4j.websock.query.WebsockQuery;
import de.hofuniversity.iisys.neo4j.websock.result.TableResult;
import de.hofuniversity.iisys.neo4j.websock.session.WebsockConstants;

/**
 * Implementation of the GroupService interface retrieving group data from a remote Neo4j graph
 * database over a websocket using Cypher.
 */
@Singleton
public class WsCypherGroupSPI implements GroupService {
    private static final String GROUPS_QUERY_NAME = "cGroups";
    private static final String GROUPS_QUERY = "START person=node:" + Constants.PERSON_NODES + "(id = {id})\n"
            + "MATCH person-[:MEMBER_OF]->group\n" + "RETURN group";

    private final IQueryHandler fQueryHandler;

    private final Logger fLogger;

    /**
     * Creates a new Cypher group service using the given query handler to retrieve data from a Neo4j
     * instance over a websocket using Cypher. The given query handler must not be null.
     *
     * @param qHandler
     *          query handler to use
     */
    @Inject
    public WsCypherGroupSPI(IQueryHandler qHandler) {
        if (qHandler == null) {
            throw new NullPointerException("Query handler was null");
        }

        this.fQueryHandler = qHandler;
        this.fLogger = Logger.getLogger(this.getClass().getName());

        // initialize stored procedures
        // delete query
        final WebsockQuery wsQuery = new WebsockQuery(EQueryType.STORE_PROCEDURE);
        wsQuery.setPayload(WsCypherGroupSPI.GROUPS_QUERY);
        wsQuery.setParameter(WebsockConstants.PROCEDURE_NAME, WsCypherGroupSPI.GROUPS_QUERY_NAME);

        try {
            this.fQueryHandler.sendMessage(wsQuery).get();
        } catch (final Exception e) {
            e.printStackTrace();
            this.fLogger.log(Level.SEVERE, "server error", e);
            throw new RuntimeException(
                    "could not store procedure \"" + wsQuery.getParameter(WebsockConstants.PROCEDURE_NAME), e);
        }
    }

    @SuppressWarnings("unchecked")
    @Override
    public Future<RestfulCollection<Group>> getGroups(UserId userId, CollectionOptions options, Set<String> fields,
            SecurityToken token) throws ProtocolException {
        final List<Group> groupList = new ArrayList<Group>();
        final WebsockQuery wsQuery = new WebsockQuery(EQueryType.PROCEDURE_CALL);

        if (options != null) {
            CollOptsConverter.convert(options, wsQuery);
        }

        // set parameters
        wsQuery.setPayload(WsCypherGroupSPI.GROUPS_QUERY_NAME);
        wsQuery.setParameter("id", userId.getUserId(token));

        // execute
        final IQueryCallback callback = this.fQueryHandler.sendQuery(wsQuery);
        TableResult result = null;

        try {
            result = (TableResult) callback.get();
        } catch (final Exception e) {
            e.printStackTrace();
            this.fLogger.log(Level.SEVERE, "server error", e);
            throw new ProtocolException(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "could not retrieve result",
                    e);
        }

        // wrap results
        Map<String, Object> gMap = null;
        for (final List<Object> gList : result.getResults()) {
            gMap = (Map<String, Object>) gList.get(0);
            groupList.add(new GroupDTO(gMap));
        }

        final RestfulCollection<Group> rColl = new RestfulCollection<Group>(groupList);
        rColl.setStartIndex(result.getFirst());
        rColl.setTotalResults(result.getTotal());
        rColl.setItemsPerPage(result.getMax());
        return Futures.immediateFuture(rColl);
    }
}