org.apache.flink.api.java.operators.translation

Class KeyExtractingMapper<T,K>

java.lang.Object

org.apache.flink.api.common.functions.AbstractRichFunction

org.apache.flink.api.common.functions.RichMapFunction<T,Tuple2<K,T>>

org.apache.flink.api.java.operators.translation.KeyExtractingMapper<T,K>

All Implemented Interfaces:

Serializable, Function, MapFunction<T,Tuple2<K,T>>, RichFunction

@Internal
public final class KeyExtractingMapper<T,K>
extends RichMapFunction<T,Tuple2<K,T>>

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
KeyExtractingMapper(KeySelector<T,K> keySelector)

Method Summary

Modifier and Type	Method and Description
Tuple2<K,T>	map(T value) The mapping method.

Methods inherited from class org.apache.flink.api.common.functions.AbstractRichFunction

close, getIterationRuntimeContext, getRuntimeContext, open, setRuntimeContext

Methods inherited from class java.lang.Object

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

Constructor Detail

KeyExtractingMapper

public KeyExtractingMapper(KeySelector<T,K> keySelector)

Method Detail

map

public Tuple2<K,T> map(T value)
                throws Exception

Description copied from interface: MapFunction

The mapping method. Takes an element from the input data set and transforms it into exactly one element.

Specified by:

map in interface MapFunction<T,Tuple2<K,T>>

Specified by:

map in class RichMapFunction<T,Tuple2<K,T>>

Parameters:

value - The input value.

Returns:

The transformed value

Throws:

Exception - This method may throw exceptions. Throwing an exception will cause the operation to fail and may trigger recovery.