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(CompletableFuture<org.apache.flink.runtime.jobgraph.OperatorID> operatorIdFuture, org.apache.flink.api.common.typeutils.TypeSerializer<T> serializer, String accumulatorName, CheckpointConfig checkpointConfig)
CollectResultIterator(AbstractCollectResultBuffer<T> buffer, CompletableFuture<org.apache.flink.runtime.jobgraph.OperatorID> operatorIdFuture, String accumulatorName, int retryMillis)

Method Summary

Modifier and Type	Method	Description
void	close()
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 Detail

CollectResultIterator

public CollectResultIterator(CompletableFuture<org.apache.flink.runtime.jobgraph.OperatorID> operatorIdFuture,
                             org.apache.flink.api.common.typeutils.TypeSerializer<T> serializer,
                             String accumulatorName,
                             CheckpointConfig checkpointConfig)

CollectResultIterator

@VisibleForTesting
public CollectResultIterator(AbstractCollectResultBuffer<T> buffer,
                             CompletableFuture<org.apache.flink.runtime.jobgraph.OperatorID> operatorIdFuture,
                             String accumulatorName,
                             int retryMillis)

Method Detail

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)