# Package org.apache.hadoop.mapreduce.lib.map

- Class Summary
  Class | Description
  --- | ---
  InverseMapper<K,V> | A `Mapper` that swaps keys and values.
  MultithreadedMapper<K1,V1,K2,V2> | Multithreaded implementation for @link org.apache.hadoop.mapreduce.Mapper.
  RegexMapper<K> | A `Mapper` that extracts text matching a regular expression.
  TokenCounterMapper | Tokenize the input values and emit each word with a count of 1.
  WrappedMapper<KEYIN,VALUEIN,KEYOUT,VALUEOUT> | A `Mapper` which wraps a given one to allow custom `Mapper.Context` implementations.

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