/** * Copyright 2005 The Apache Software Foundation * * Licensed 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.hadoop.io;import java.io.IOException;/** Thrown by {@link VersionedWritable#readFields(DataInput)} when the * version of an object being read does not match the current implementation * version as returned by {@link VersionedWritable#getVersion()}. */public class VersionMismatchException extends IOException {  private byte expectedVersion;  private byte foundVersion;  public VersionMismatchException(byte expectedVersionIn, byte foundVersionIn){    expectedVersion = expectedVersionIn;    foundVersion = foundVersionIn;  }  /** Returns a string representation of this object. */  public String toString(){    return "A record version mismatch occured. Expecting v"      + expectedVersion + ", found v" + foundVersion;   }}