MapReduceBase (Apache Hadoop Main 3.5.0 API)
Description: declaration: package: org.apache.hadoop.mapred, class: MapReduceBase

Package org.apache.hadoop.mapred

# Class MapReduceBase

java.lang.Object
org.apache.hadoop.mapred.MapReduceBase

All Implemented Interfaces:
  `Closeable`, `AutoCloseable`, `Closeable`, `JobConfigurable`

Direct Known Subclasses:
  `IdentityMapper`, `IdentityReducer`, `InverseMapper`, `LongSumReducer`, `RegexMapper`, `TokenCountMapper`

@Public @Stable public class MapReduceBase extends Object implements Closeable, JobConfigurable
Base class for `Mapper` and `Reducer` implementations.

Provides default no-op implementations for a few methods, most non-trivial applications need to override some of them.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `MapReduceBase()`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `close()`
  Default implementation that does nothing.
  `void`
  `configure(JobConf job)`
  Default implementation that does nothing.

  ### Methods inherited from class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Constructor Details

  - ### MapReduceBase

    public MapReduceBase()

- ## Method Details

  - ### close

    public void close() throws IOException
    Default implementation that does nothing.
    Specified by:
      `close` in interface `AutoCloseable`
    Specified by:
      `close` in interface `Closeable`
    Throws:
      `IOException`

  - ### configure

    public void configure(JobConf job)
    Default implementation that does nothing.
    Specified by:
      `configure` in interface `JobConfigurable`
    Parameters:
      `job` - the configuration