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.mapred;
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     
036      private static final long serialVersionUID = 1L;
037      private List<IOException> problems;
038      
039      /**
040       * Create the exception with the given list.
041       * @param probs the list of problems to report. this list is not copied.
042       */
043      public InvalidInputException(List<IOException> probs) {
044        problems = probs;
045      }
046      
047      /**
048       * Get the complete list of the problems reported.
049       * @return the list of problems, which must not be modified
050       */
051      public List<IOException> getProblems() {
052        return problems;
053      }
054      
055      /**
056       * Get a summary message of the problems found.
057       * @return the concatenated messages from all of the problems.
058       */
059      public String getMessage() {
060        StringBuffer result = new StringBuffer();
061        Iterator<IOException> itr = problems.iterator();
062        while(itr.hasNext()) {
063          result.append(itr.next().getMessage());
064          if (itr.hasNext()) {
065            result.append("\n");
066          }
067        }
068        return result.toString();
069      }
070    }