001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.io;
020
021import java.io.IOException;
022
023import org.apache.hadoop.classification.InterfaceAudience;
024import org.apache.hadoop.classification.InterfaceStability;
025
026/** Thrown by {@link VersionedWritable#readFields(DataInput)} when the
027 * version of an object being read does not match the current implementation
028 * version as returned by {@link VersionedWritable#getVersion()}. */
029@InterfaceAudience.Public
030@InterfaceStability.Stable
031public class VersionMismatchException extends IOException {
032
033  private byte expectedVersion;
034  private byte foundVersion;
035
036  public VersionMismatchException(byte expectedVersionIn, byte foundVersionIn){
037    expectedVersion = expectedVersionIn;
038    foundVersion = foundVersionIn;
039  }
040
041  /** Returns a string representation of this object. */
042  @Override
043  public String toString(){
044    return "A record version mismatch occurred. Expecting v"
045      + expectedVersion + ", found v" + foundVersion; 
046  }
047}