content: /*
   * Copyright (c) 2013 - 2014, Allen A. George <allen dot george at gmail dot com>
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *     * Redistributions of source code must retain the above copyright
   *       notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above copyright
   *       notice, this list of conditions and the following disclaimer in the
   *       documentation and/or other materials provided with the distribution.
   *     * Neither the name of libraft nor the
   *       names of its contributors may be used to endorse or promote products
   *       derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package io.libraft;
  
  import javax.annotation.Nullable;
  
  /**
   * Thrown when a {@link Command} is submitted to a {@link Raft} instance
   * and it is not the leader.
   */
  @SuppressWarnings("unused")
  public final class NotLeaderException extends RaftException {
  
      private static final long serialVersionUID = 6131822943716006815L;
  
      private String self;
      private @Nullable String leader;
  
      private NotLeaderException() { }
  
      private NotLeaderException(String message) {
          super(message);
      }
  
      private NotLeaderException(Throwable cause) {
          super(cause);
      }
  
      private NotLeaderException(String message, Throwable cause) {
          super(message, cause);
      }
  
      /**
       * Constructor
       *
       * @param self unique id of the server
       * @param leader unique id of the current leader server (if known)
       */
      public NotLeaderException(String self, @Nullable String leader) {
          super(leader != null
                  ?
                  String.format("%s not leader - current leader: %s", self, leader)
                  :
                  String.format("%s not leader - cluster has no leader", self)
          );
          this.self = self;
          this.leader = leader;
      }
  
      /**
       * @return the unique id of the server that threw the exception (i.e. the follower server)
       */
      public String getSelf() {
          return self;
      }
  
      /**
       * @return the unique id of the current leader server, or {@code null} if the current leader is unknown
       */
      public @Nullable String getLeader() {
          return leader;
      }
  }
  