dk.au.cs.karibu.backend.mongo.MongoDBStorage.java Source code

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Here is the source code for dk.au.cs.karibu.backend.mongo.MongoDBStorage.java

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/*
 * Copyright 2013 Henrik Baerbak Christensen, Aarhus 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.
 */

package dk.au.cs.karibu.backend.mongo;

import java.util.List;

import org.apache.commons.lang.exception.ExceptionUtils;
import org.slf4j.*;

import com.mongodb.*;

import dk.au.cs.karibu.backend.*;

/** MongoDB implementation of the Storage interface. 
 *  
 * Regarding connecting to replica sets, tutorial at
 *  
 * http://dev.af83.com/2010/11/02/mini-howto-using-the-replica-set-of-mongodb-in-java.html 
 *  
 * is a good source. 
 *  
 * @author Henrik Baerbak Christensen, Aarhus University 
 */
public class MongoDBStorage implements ProcessingStrategy, StatisticStorageStrategy {

    // --*-- Fields --*--

    private static final String KARIBU_STATISTIC_COLLECTION_NAME = "karibu.statistic";

    private Mongo mongoDB;
    private DB database;
    private DBCollection coll;
    private Logger log;

    // --*-- Constructors --*--

    /** Connect the storage to a MongoDB replica set 
     *  
     * @param configuration properties of the configuration 
     */
    public MongoDBStorage(MongoConfiguration configuration) {
        log = LoggerFactory.getLogger(MongoDBStorage.class);
        log.info("MongoDB initializing with configuration: " + configuration.toString());

        createConnection(configuration);
    }

    // --*-- Methods --*--

    private void createConnection(MongoConfiguration conf) {

        String databaseName = conf.getDatabaseName();
        List<ServerAddress> addr = conf.getServerAddressList();

        // connect to the database server 
        mongoDB = null;
        try {
            mongoDB = new MongoClient(addr);
        } catch (MongoException e) {
            String theTrace = ExceptionUtils.getStackTrace(e);
            log.error("MongoException. " + theTrace);
            System.exit(-1);
        }
        // get handle to the required database 
        database = mongoDB.getDB(databaseName);
        // authenticate in case there is a username in the config
        if (conf.getUsername() != null) {
            boolean auth = database.authenticate(conf.getUsername(), conf.getPassword().toCharArray());
            if (!auth) {
                log.error("Mongo authentication failed for username: " + conf.getUsername() + " on DB: "
                        + conf.getDatabaseName());
                System.out.println("MongoDB authentication failed. Review log.");
                // Fail fast!
                System.exit(-1);
            }
        }

        // From javadoc:  
        // By default, all read and write operations will be made on the primary,  
        // but it's possible to read from secondaries by changing the read preference 
        mongoDB.setReadPreference(ReadPreference.secondaryPreferred());

        // From javadoc: Exceptions are raised for network issues, and server errors;  
        // waits on a server for the write operation 
        mongoDB.setWriteConcern(WriteConcern.SAFE);

        log.info("MongoDB connected...");

        // Register a shutdown hook to close the mongo  
        // connection 
        Runtime.getRuntime().addShutdownHook(new Thread() {
            public void run() {
                log.info("MongoDB disconnected...");
                mongoDB.close();
            }
        });

    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void process(String producerCode, BasicDBObject dbo) {
        // get a collection object to work with 
        coll = database.getCollection(producerCode);
        // Insert it into Mongo 
        WriteResult writeResult = coll.insert(dbo);
        CommandResult err = writeResult.getCachedLastError();
        if (!err.ok()) {
            log.error("MongoDB insert failed with result: " + err.toString());
        }
    }

    // Temporary methods - should not hit production code 
    @Deprecated
    public DBCollection getCollection(String collectionName) {
        return database.getCollection(collectionName);
    }

    @Override
    public void store(BasicDBObject dbo) {
        // get the karibu statistics collection object
        coll = database.getCollection(KARIBU_STATISTIC_COLLECTION_NAME);
        // Insert it into Mongo 
        WriteResult writeResult = coll.insert(dbo);
        CommandResult err = writeResult.getCachedLastError();
        if (!err.ok()) {
            log.error("MongoDB insert failed with result: " + err.toString());
        }
        // System.err.println("Will store "+dbo);
    }
}