org.apache.flink.streaming.api.functions.source

Class RichSourceFunction<OUT>

java.lang.Object

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

org.apache.flink.streaming.api.functions.source.RichSourceFunction<OUT>

Type Parameters:

OUT - The type of the records produced by this source.

All Implemented Interfaces:

Serializable, Function, RichFunction, SourceFunction<OUT>

Direct Known Subclasses:

ContinuousFileMonitoringFunction, MessageAcknowledgingSourceBase, PubSubSource, TwitterSource, WikipediaEditsSource

@Public
public abstract class RichSourceFunction<OUT>
extends AbstractRichFunction
implements SourceFunction<OUT>

Base class for implementing a parallel data source that has access to context information (via AbstractRichFunction.getRuntimeContext()) and additional life-cycle methods (AbstractRichFunction.open(org.apache.flink.configuration.Configuration) and AbstractRichFunction.close().

This class is useful when implementing parallel sources where different parallel subtasks need to perform different work. Typical patterns for that are:

• Use AbstractRichFunction.getRuntimeContext() to obtain the runtime context.
• Use RuntimeContext.getNumberOfParallelSubtasks() to determine the current parallelism. It is strongly encouraged to use this method, rather than hard-wiring the parallelism, because the configured parallelism may change depending on program configuration. The parallelism may also change after recovering failures, when fewer than desired parallel worker as available.
• Use RuntimeContext.getIndexOfThisSubtask() to determine which subtask the current instance of the function executes.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.streaming.api.functions.source.SourceFunction

SourceFunction.SourceContext<T>

Constructor Summary

Constructors

Constructor and Description
RichSourceFunction()

Method Summary

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

Methods inherited from interface org.apache.flink.streaming.api.functions.source.SourceFunction

cancel, run

Constructor Detail

RichSourceFunction

public RichSourceFunction()