/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements. See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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 org.apache.logging.log4j.core.appender;
  
  import org.apache.logging.log4j.Logger;
  import org.apache.logging.log4j.core.config.AppenderRef;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.config.plugins.PluginElement;
  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
  import org.apache.logging.log4j.status.StatusLogger;
  
  /**
   * The array of failover Appenders.
   */
  @Plugin(name = "failovers", category = "Core")
  public final class FailoversPlugin {
  
      private static final Logger LOGGER = StatusLogger.getLogger();
  
      /**
       * Prevent instantiation.
       */
      private FailoversPlugin() {
      }
  
      /**
       * Returns the appender references.
       * @param refs The references to return.
       * @return The appender references.
       */
      @PluginFactory
      public static String[] createFailovers(@PluginElement("AppenderRef") final AppenderRef... refs) {
  
          if (refs == null) {
              LOGGER.error("failovers must contain an appender reference");
              return null;
          }
          final String[] arr = new String[refs.length];
          for (int i = 0; i < refs.length; ++i) {
              arr[i] = refs[i].getRef();
          }
          return arr;
      }
  }