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    
019    package org.apache.hadoop.io;
020    
021    import java.io.IOException;
022    
023    import org.apache.hadoop.classification.InterfaceAudience;
024    import 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
031    public 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    }