org.apache.flink.streaming.api.scala

Class CoGroupedStreams<T1,T2>

java.lang.Object

org.apache.flink.streaming.api.scala.CoGroupedStreams<T1,T2>

public class CoGroupedStreams<T1,T2>
extends Object

CoGroupedStreams represents two DataStreams that have been co-grouped. A streaming co-group operation is evaluated over elements in a window.

To finalize the co-group operation you also need to specify a KeySelector for both the first and second input and a WindowAssigner

Note: Right now, the groups are being built in memory so you need to ensure that they don't get too big. Otherwise the JVM might crash.

Example:

 val one: DataStream[(String, Int)]  = ...
 val two: DataStream[(String, Int)] = ...

 val result = one.coGroup(two)
     .where(new MyFirstKeySelector())
     .equalTo(new MyFirstKeySelector())
     .window(TumblingEventTimeWindows.of(Time.of(5, TimeUnit.SECONDS)))
     .apply(new MyCoGroupFunction())
 } 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	CoGroupedStreams.Where<KEY> A co-group operation that has KeySelectors defined for the first input.

Constructor Summary

Constructors

Constructor and Description
CoGroupedStreams(DataStream<T1> input1, DataStream<T2> input2)

Method Summary

Modifier and Type	Method and Description
<F> F	clean(F f) Returns a "closure-cleaned" version of the given function.
<KEY> CoGroupedStreams.Where<KEY>	where(scala.Function1<T1,KEY> keySelector, TypeInformation<KEY> evidence$1) Specifies a KeySelector for elements from the first input.

Methods inherited from class java.lang.Object

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

Constructor Detail

CoGroupedStreams

public CoGroupedStreams(DataStream<T1> input1,
                        DataStream<T2> input2)

Method Detail

where

public <KEY> CoGroupedStreams.Where<KEY> where(scala.Function1<T1,KEY> keySelector,
                                               TypeInformation<KEY> evidence$1)

Specifies a KeySelector for elements from the first input.

clean

public <F> F clean(F f)

Returns a "closure-cleaned" version of the given function. Cleans only if closure cleaning is not disabled in the ExecutionConfig.