    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.core.appender;
    018
    019    import org.apache.logging.log4j.Logger;
    020    import org.apache.logging.log4j.core.config.AppenderRef;
    021    import org.apache.logging.log4j.core.config.plugins.Plugin;
    022    import org.apache.logging.log4j.core.config.plugins.PluginElement;
    023    import org.apache.logging.log4j.core.config.plugins.PluginFactory;
    024    import org.apache.logging.log4j.status.StatusLogger;
    025
    026    /**
    027     * The array of failover Appenders.
    028     */
    029    @Plugin(name = "failovers", category = "Core")
    030    public final class FailoversPlugin {
    031
    032        private static final Logger LOGGER = StatusLogger.getLogger();
    033
    034        /**
    035         * Prevent instantiation.
    036         */
    037        private FailoversPlugin() {
    038        }
    039
    040        /**
    041         * Returns the appender references.
    042         * @param refs The references to return.
    043         * @return The appender references.
    044         */
    045        @PluginFactory
    046        public static String[] createFailovers(@PluginElement("AppenderRef") final AppenderRef... refs) {
    047
    048            if (refs == null) {
    049                LOGGER.error("failovers must contain an appender reference");
    050                return null;
    051            }
    052            final String[] arr = new String[refs.length];
    053            for (int i = 0; i < refs.length; ++i) {
    054                arr[i] = refs[i].getRef();
    055            }
    056            return arr;
    057        }
    058    }