code: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.godhuli.rhipe;
  
  import org.apache.hadoop.io.Writable;
  import org.apache.hadoop.io.WritableComparable;
  import org.apache.hadoop.mapreduce.InputSplit;
  import org.apache.hadoop.mapreduce.RecordReader;
  import org.apache.hadoop.mapreduce.TaskAttemptContext;
  import org.apache.hadoop.mapreduce.lib.input.SequenceFileRecordReader;
  
  import java.io.IOException;
  
  /**
   * This class converts the input keys and values to their String forms by
   * calling toString() method. This class to SequenceFileAsTextInputFormat
   * class is as LineRecordReader class to TextInputFormat class.
   */
  public class SequenceFileAsRHTextRecordReader extends RecordReader<RHText, RHText> {
  
      private final SequenceFileRecordReader<WritableComparable<?>, Writable> sequenceFileRecordReader;
  
      private RHText key;
      private RHText value;
  
      public SequenceFileAsRHTextRecordReader() throws IOException {
          sequenceFileRecordReader = new SequenceFileRecordReader<WritableComparable<?>, Writable>();
      }
  
      public void initialize(final InputSplit split, final TaskAttemptContext context) throws IOException, InterruptedException {
          sequenceFileRecordReader.initialize(split, context);
      }
  
      @Override
      public RHText getCurrentKey() throws IOException, InterruptedException {
          return key;
      }
  
      @Override
      public RHText getCurrentValue() throws IOException, InterruptedException {
          return value;
      }
  
      /**
       * Read key/value pair in a line.
       */
      public synchronized boolean nextKeyValue() throws IOException, InterruptedException {
          if (!sequenceFileRecordReader.nextKeyValue()) {
              return false;
          }
          if (key == null) {
              key = new RHText();
          }
          if (value == null) {
              value = new RHText();
          }
          key.setAndFinis(sequenceFileRecordReader.getCurrentKey().toString());
          value.setAndFinis(sequenceFileRecordReader.getCurrentValue().toString());
          return true;
      }
  
      public float getProgress() throws IOException, InterruptedException {
          return sequenceFileRecordReader.getProgress();
      }
  
      public synchronized void close() throws IOException {
          sequenceFileRecordReader.close();
      }
  }
  