    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements. See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache license, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License. You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the license for the specific language governing permissions and
    015     * limitations under the license.
    016     */
    017    package org.apache.logging.log4j.nosql.appender.mongodb;
    018
    019    import org.apache.logging.log4j.Level;
    020    import org.apache.logging.log4j.Logger;
    021    import org.apache.logging.log4j.core.appender.AppenderLoggingException;
    022    import org.apache.logging.log4j.nosql.appender.NoSqlConnection;
    023    import org.apache.logging.log4j.nosql.appender.NoSqlObject;
    024    import org.apache.logging.log4j.status.StatusLogger;
    025    import org.apache.logging.log4j.util.Strings;
    026    import org.bson.BSON;
    027    import org.bson.Transformer;
    028
    029    import com.mongodb.BasicDBObject;
    030    import com.mongodb.DB;
    031    import com.mongodb.DBCollection;
    032    import com.mongodb.Mongo;
    033    import com.mongodb.MongoException;
    034    import com.mongodb.WriteConcern;
    035    import com.mongodb.WriteResult;
    036
    037    /**
    038     * The MongoDB implementation of {@link NoSqlConnection}.
    039     */
    040    public final class MongoDbConnection implements NoSqlConnection<BasicDBObject, MongoDbObject> {
    041
    042        private static final Logger LOGGER = StatusLogger.getLogger();
    043
    044        static {
    045            BSON.addEncodingHook(Level.class, new Transformer() {
    046                @Override
    047                public Object transform(final Object o) {
    048                    if (o instanceof Level) {
    049                        return ((Level) o).name();
    050                    }
    051                    return o;
    052                }
    053            });
    054        }
    055
    056        private final DBCollection collection;
    057        private final Mongo mongo;
    058        private final WriteConcern writeConcern;
    059
    060        public MongoDbConnection(final DB database, final WriteConcern writeConcern, final String collectionName) {
    061            this.mongo = database.getMongo();
    062            this.collection = database.getCollection(collectionName);
    063            this.writeConcern = writeConcern;
    064        }
    065
    066        @Override
    067        public MongoDbObject createObject() {
    068            return new MongoDbObject();
    069        }
    070
    071        @Override
    072        public MongoDbObject[] createList(final int length) {
    073            return new MongoDbObject[length];
    074        }
    075
    076        @Override
    077        public void insertObject(final NoSqlObject<BasicDBObject> object) {
    078            try {
    079                final WriteResult result = this.collection.insert(object.unwrap(), this.writeConcern);
    080                if (Strings.isNotEmpty(result.getError())) {
    081                    throw new AppenderLoggingException("Failed to write log event to MongoDB due to error: " +
    082                            result.getError() + '.');
    083                }
    084            } catch (final MongoException e) {
    085                throw new AppenderLoggingException("Failed to write log event to MongoDB due to error: " + e.getMessage(),
    086                        e);
    087            }
    088        }
    089
    090        @Override
    091        public void close() {
    092            // there's no need to call this.mongo.close() since that literally closes the connection
    093            // MongoDBClient uses internal connection pooling
    094            // for more details, see LOG4J2-591
    095        }
    096
    097        @Override
    098        public boolean isClosed() {
    099            return !this.mongo.getConnector().isOpen();
    100        }
    101
    102        /**
    103         * To prevent class loading issues during plugin discovery, this code cannot live within MongoDbProvider. This
    104         * is because of how Java treats references to Exception classes different from references to other classes. When
    105         * Java loads a class, it normally won't load that class's dependent classes until and unless A) they are used, B)
    106         * the class being loaded extends or implements those classes, or C) those classes are the types of static members
    107         * in the class. However, exceptions that a class uses are always loaded when the class is loaded, even before
    108         * they are actually used.
    109         *
    110         * @param database The database to authenticate
    111         * @param username The username to authenticate with
    112         * @param password The password to authenticate with
    113         */
    114        static void authenticate(final DB database, final String username, final String password) {
    115            try {
    116                if (!database.authenticate(username, password.toCharArray())) {
    117                    LOGGER.error("Failed to authenticate against MongoDB server. Unknown error.");
    118                }
    119            } catch (final MongoException e) {
    120                LOGGER.error("Failed to authenticate against MongoDB: " + e.getMessage(), e);
    121            } catch (final IllegalStateException e) {
    122                LOGGER.error("Factory-supplied MongoDB database connection already authenticated with different" +
    123                        "credentials but lost connection.", e);
    124            }
    125        }
    126    }