com.bbc.remarc.db.MongoClient.java Source code

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Here is the source code for com.bbc.remarc.db.MongoClient.java

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/*
 * Copyright (C) 2016 BBC
 *
 * 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.bbc.remarc.db;

import java.net.UnknownHostException;

import org.apache.log4j.Logger;

import com.bbc.remarc.util.Configuration;
import com.mongodb.DB;
import com.mongodb.Mongo;

/**
 * Singleton instance of Mongo connection pool. 
 * Initialised as ServletContextListener
 * @author Peter Brock
 * @author Mark Fearnley
 *
 */
public class MongoClient {

    private static Logger log = Logger.getLogger(MongoClient.class);

    private static Mongo mongo;
    private static DB mongoDB;

    private static boolean authenticated;
    private static String username;
    private static String password;
    private static String db;
    private static String host;
    private static String portStr;
    private static Integer port;

    private MongoClient() {
    }

    /**
     * Connect to mongo instance using env variables if present
     * or fall back to local instance
     * @return
     * @throws UnknownHostException
     */
    public static synchronized Mongo connect() {

        if (mongo == null) {

            log.debug("Creating new MongoDB connection");

            host = System.getenv(Configuration.ENV_MONGO_HOST_OPENSHIFT);
            if (host == null || "".equals(host)) {
                log.info("Not running on OpenShift. Falling back to local mongodb");

                username = System.getenv(Configuration.ENV_MONGO_USER_LOCAL);
                password = System.getenv(Configuration.ENV_MONGO_PWD_LOCAL);
                db = System.getenv(Configuration.ENV_MONGO_DB_LOCAL);
                host = System.getenv(Configuration.ENV_MONGO_HOST_LOCAL);
                portStr = System.getenv(Configuration.ENV_MONGO_PORT_LOCAL);

                if (username == null || "".equals(username)) {
                    log.debug("No username found in local environment variables, assuming default");
                    username = "remarc";
                }

                if (password == null || "".equals(password)) {
                    log.debug("No password found in local environment variables, assuming default");
                    password = "dementia";
                }

                if (db == null || "".equals(db)) {
                    log.debug("No database found in local environment variables, assuming default");
                    db = "remarc";
                }

                if (host == null || "".equals(host)) {
                    log.debug("No host found in local environment variables, assuming default");
                    host = "localhost";
                }

                if (portStr == null || "".equals(portStr)) {
                    log.debug("No port found in local environment variables, assuming default");
                    portStr = "27017";
                }

                port = Integer.decode(portStr);

            } else {

                log.info("Running on OpenShift. Configuring connection");

                portStr = System.getenv(Configuration.ENV_MONGO_PORT_OPENSHIFT);
                port = Integer.decode(portStr);

                username = System.getenv(Configuration.ENV_MONGO_USER_OPENSHIFT);
                password = System.getenv(Configuration.ENV_MONGO_PWD_OPENSHIFT);
                db = System.getenv(Configuration.ENV_MONGO_DB_OPENSHIFT);

            }

            try {
                mongo = new Mongo(host, port);
            } catch (UnknownHostException ex) {
                throw new RuntimeException("Failed to connect to db", ex);
            }

        }

        return mongo;
    }

    /**
     * Get hold of the remarc database instance
     * @return
     */
    public static synchronized DB getDB() {

        if (mongoDB == null) {

            if (mongo == null) {

                connect();
            }

            log.debug("Retrieving database");
            mongoDB = mongo.getDB(db);

            // only authenticate if we're not already authenticated
            if (!authenticated) {

                log.debug("Not authenticated against database. Authenticating now.");
                authenticated = mongoDB.authenticate(username, password.toCharArray());

                if (!authenticated) {
                    throw new RuntimeException("Failed to authenticate against db");
                }
            }

        }

        return mongoDB;

    }

    /**
     * Shutdown the mongo instance
     */
    public static void disconnect() {

        log.info("Disconnecting mongo client");
        if (mongo != null) {
            mongo.close();
        }
    }
}