Package org.apache.hadoop.mapreduce.lib.output

Class NullOutputFormat<K,V>

java.lang.Object
org.apache.hadoop.mapreduce.OutputFormat<K,V>
org.apache.hadoop.mapreduce.lib.output.NullOutputFormat<K,V>
@Public @Stable public class NullOutputFormat<K,V> extends OutputFormat<K,V>
Consume all outputs and put them in /dev/null.

  • Constructor Details

    • NullOutputFormat

      public NullOutputFormat()

  • Method Details

    • getRecordWriter

      public RecordWriter<K,V> getRecordWriter(TaskAttemptContext context)
      Description copied from class: OutputFormat
      Get the RecordWriter for the given task.
      Specified by:
      getRecordWriter in class OutputFormat<K,V>
      Parameters:
      context - the information about the current task.
      Returns:
      a RecordWriter to write the output for the job.

    • checkOutputSpecs

      public void checkOutputSpecs(JobContext context)
      Description copied from class: OutputFormat
      Check for validity of the output-specification for the job.

      This is to validate the output specification for the job when it is a job is submitted. Typically checks that it does not already exist, throwing an exception when it already exists, so that output is not overwritten.

      Implementations which write to filesystems which support delegation tokens usually collect the tokens for the destination path(s) and attach them to the job context's JobConf.
      Specified by:
      checkOutputSpecs in class OutputFormat<K,V>
      Parameters:
      context - information about the job

    • getOutputCommitter

      public OutputCommitter getOutputCommitter(TaskAttemptContext context)
      Description copied from class: OutputFormat
      Get the output committer for this output format. This is responsible for ensuring the output is committed correctly.
      Specified by:
      getOutputCommitter in class OutputFormat<K,V>
      Parameters:
      context - the task context
      Returns:
      an output committer