com.conductor.hadoop.DelegatingRecordReader.java Source code

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Here is the source code for com.conductor.hadoop.DelegatingRecordReader.java

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/**
 * 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 com.conductor.hadoop;

import java.io.IOException;

import org.apache.hadoop.mapreduce.*;
import org.apache.hadoop.util.ReflectionUtils;

/**
 * This class is taken directly from the Hadoop source code so that we can leverage {@link TaggedInputSplit} which is
 * package-private in the Hadoop library.
 * 
 * @see org.apache.hadoop.mapreduce.lib.input.DelegatingRecordReader
 * @see com.conductor.kafka.hadoop.MultipleKafkaInputFormat
 */
public class DelegatingRecordReader<K, V> extends RecordReader<K, V> {
    RecordReader<K, V> originalRR;

    @SuppressWarnings("unchecked")
    public DelegatingRecordReader(InputSplit split, TaskAttemptContext context)
            throws IOException, InterruptedException {
        // Find the InputFormat and then the RecordReader from the TaggedInputSplit.
        TaggedInputSplit taggedInputSplit = (TaggedInputSplit) split;
        InputFormat<K, V> inputFormat = (InputFormat<K, V>) ReflectionUtils
                .newInstance(taggedInputSplit.getInputFormatClass(), context.getConfiguration());
        originalRR = inputFormat.createRecordReader(taggedInputSplit.getInputSplit(), context);
    }

    @Override
    public void close() throws IOException {
        originalRR.close();
    }

    @Override
    public K getCurrentKey() throws IOException, InterruptedException {
        return originalRR.getCurrentKey();
    }

    @Override
    public V getCurrentValue() throws IOException, InterruptedException {
        return originalRR.getCurrentValue();
    }

    @Override
    public float getProgress() throws IOException, InterruptedException {
        return originalRR.getProgress();
    }

    @Override
    public void initialize(InputSplit split, TaskAttemptContext context) throws IOException, InterruptedException {
        originalRR.initialize(((TaggedInputSplit) split).getInputSplit(), context);
    }

    @Override
    public boolean nextKeyValue() throws IOException, InterruptedException {
        return originalRR.nextKeyValue();
    }

}