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

Class PlanUnwrappingReduceOperator.ReduceWrapper<T,K>

java.lang.Object

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

org.apache.flink.api.java.operators.translation.WrappingFunction<ReduceFunction<T>>

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

All Implemented Interfaces:

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

Enclosing class:

PlanUnwrappingReduceOperator<T,K>

public static final class PlanUnwrappingReduceOperator.ReduceWrapper<T,K>
extends WrappingFunction<ReduceFunction<T>>
implements ReduceFunction<Tuple2<K,T>>

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.flink.api.java.operators.translation.WrappingFunction

wrappedFunction

Method Summary

Modifier and Type	Method and Description
Tuple2<K,T>	reduce(Tuple2<K,T> value1, Tuple2<K,T> value2) The core method of ReduceFunction, combining two values into one value of the same type.

Methods inherited from class org.apache.flink.api.java.operators.translation.WrappingFunction

close, getWrappedFunction, open, setRuntimeContext

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

getIterationRuntimeContext, getRuntimeContext

Methods inherited from class java.lang.Object

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

Method Detail

reduce

public Tuple2<K,T> reduce(Tuple2<K,T> value1,
                          Tuple2<K,T> value2)
                   throws Exception

Description copied from interface: ReduceFunction

The core method of ReduceFunction, combining two values into one value of the same type. The reduce function is consecutively applied to all values of a group until only a single value remains.

Specified by:

reduce in interface ReduceFunction<Tuple2<K,T>>

Parameters:

value1 - The first value to combine.

value2 - The second value to combine.

Returns:

The combined value of both input values.

Throws:

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