Package org.apache.flink.streaming.api.operators.collect

Class CollectResultIterator<T>

java.lang.Object

org.apache.flink.streaming.api.operators.collect.CollectResultIterator<T>

All Implemented Interfaces:

AutoCloseable, Iterator<T>, org.apache.flink.util.CloseableIterator<T>

public class CollectResultIterator<T>
extends Object
implements org.apache.flink.util.CloseableIterator<T>

An iterator which iterates through the results of a query job.

The behavior of the iterator is slightly different under different checkpointing mode.

• If the user does not specify any checkpointing, results are immediately delivered but exceptions will be thrown when the job restarts.
• If the user specifies exactly-once checkpointing, results are guaranteed to be exactly-once but they're only visible after the corresponding checkpoint completes.
• If the user specifies at-least-once checkpointing, results are immediately delivered but the same result may be delivered multiple times.

NOTE: After using this iterator, the close method MUST be called in order to release job related resources.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.util.CloseableIterator

org.apache.flink.util.CloseableIterator.IteratorAdapter<E extends Object>

Field Summary

Fields inherited from interface org.apache.flink.util.CloseableIterator

EMPTY_INSTANCE

Constructor Summary

Constructors

Constructor	Description
CollectResultIterator(String operatorUid, org.apache.flink.api.common.typeutils.TypeSerializer<T> serializer, String accumulatorName, CheckpointConfig checkpointConfig, long resultFetchTimeout)
CollectResultIterator(AbstractCollectResultBuffer<T> buffer, String operatorUid, String accumulatorName, int retryMillis)

Method Summary

Modifier and Type	Method	Description
void	close()
CollectResultIterator<T>	copy()
boolean	hasNext()
T	next()
void	setJobClient(org.apache.flink.core.execution.JobClient jobClient)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Constructor Details

CollectResultIterator

public CollectResultIterator(String operatorUid,
 org.apache.flink.api.common.typeutils.TypeSerializer<T> serializer,
 String accumulatorName,
 CheckpointConfig checkpointConfig,
 long resultFetchTimeout)

CollectResultIterator

@VisibleForTesting
public CollectResultIterator(AbstractCollectResultBuffer<T> buffer,
 String operatorUid,
 String accumulatorName,
 int retryMillis)

Method Details

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<T>

next

public T next()

Specified by:

next in interface Iterator<T>

close

public void close()
           throws Exception

Specified by:

close in interface AutoCloseable

Throws:

Exception

setJobClient

public void setJobClient(org.apache.flink.core.execution.JobClient jobClient)

copy

public CollectResultIterator<T> copy()