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    package org.apache.hadoop.mapreduce.lib.input;
019    
020    import java.io.IOException;
021    import java.util.List;
022    import java.util.Iterator;
023    
024    import org.apache.hadoop.classification.InterfaceAudience;
025    import org.apache.hadoop.classification.InterfaceStability;
026    
027    /**
028     * This class wraps a list of problems with the input, so that the user
029     * can get a list of problems together instead of finding and fixing them one 
030     * by one.
031     */
032    @InterfaceAudience.Public
033    @InterfaceStability.Stable
034    public class InvalidInputException extends IOException {
035      private static final long serialVersionUID = -380668190578456802L;
036      private List<IOException> problems;
037      
038      /**
039       * Create the exception with the given list.
040       * @param probs the list of problems to report. this list is not copied.
041       */
042      public InvalidInputException(List<IOException> probs) {
043        problems = probs;
044      }
045      
046      /**
047       * Get the complete list of the problems reported.
048       * @return the list of problems, which must not be modified
049       */
050      public List<IOException> getProblems() {
051        return problems;
052      }
053      
054      /**
055       * Get a summary message of the problems found.
056       * @return the concatenated messages from all of the problems.
057       */
058      public String getMessage() {
059        StringBuffer result = new StringBuffer();
060        Iterator<IOException> itr = problems.iterator();
061        while(itr.hasNext()) {
062          result.append(itr.next().getMessage());
063          if (itr.hasNext()) {
064            result.append("\n");
065          }
066        }
067        return result.toString();
068      }
069    }