Example usage for org.apache.hadoop.mapreduce JobContext getOutputKeyClass

Introduction

In this page you can find the example usage for org.apache.hadoop.mapreduce JobContext getOutputKeyClass.

Prototype

public Class<?> getOutputKeyClass();

Source Link

Document

Get the key class for the job output data.

Usage

From source file:edu.arizona.cs.hadoop.fs.irods.output.HirodsSequenceFileAsBinaryOutputFormat.java

License:Apache License

/**
 * Get the key class for the {@link SequenceFile}
 *
 * @return the key class of the {@link SequenceFile}
 *///from www  . j a va2  s .co  m
static public Class<? extends WritableComparable> getSequenceFileOutputKeyClass(JobContext job) {
    return job.getConfiguration().getClass(KEY_CLASS,
            job.getOutputKeyClass().asSubclass(WritableComparable.class), WritableComparable.class);
}

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From source file:edu.uci.ics.hyracks.dataflow.hadoop.HadoopReducerOperatorDescriptor.java

License:Apache License

public static RecordDescriptor getRecordDescriptor(JobConf conf, IHadoopClassFactory classFactory) {
    String outputKeyClassName = null;
    String outputValueClassName = null;

    if (conf.getUseNewMapper()) {
        JobContext context = new ContextFactory().createJobContext(conf);
        outputKeyClassName = context.getOutputKeyClass().getName();
        outputValueClassName = context.getOutputValueClass().getName();
    } else {//from   w w w  .  jav  a 2s  . c  om
        outputKeyClassName = conf.getOutputKeyClass().getName();
        outputValueClassName = conf.getOutputValueClass().getName();
    }

    RecordDescriptor recordDescriptor = null;
    try {
        if (classFactory == null) {
            recordDescriptor = DatatypeHelper.createKeyValueRecordDescriptor(
                    (Class<? extends Writable>) Class.forName(outputKeyClassName),
                    (Class<? extends Writable>) Class.forName(outputValueClassName));
        } else {
            recordDescriptor = DatatypeHelper.createKeyValueRecordDescriptor(
                    (Class<? extends Writable>) classFactory.loadClass(outputKeyClassName),
                    (Class<? extends Writable>) classFactory.loadClass(outputValueClassName));
        }
    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
    return recordDescriptor;
}

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