Package org.apache.flink.state.api.functions

Class KeyedStateBootstrapFunction<K,IN>

java.lang.Object

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

org.apache.flink.state.api.functions.KeyedStateBootstrapFunction<K,IN>

Type Parameters:

K - Type of the keys.

IN - Type of the input.

All Implemented Interfaces:

Serializable, Function, RichFunction

@PublicEvolving
public abstract class KeyedStateBootstrapFunction<K,IN>
extends AbstractRichFunction

A function that writes keyed state to a new operator.

For every element #processElement(Object, Context) is invoked. This can write data to state and set timers.

NOTE: A KeyedStateBootstrapFunction is always a RichFunction. Therefore, access to the RuntimeContext is always available and setup and teardown methods can be implemented. See RichFunction.open(OpenContext) and RichFunction.close().

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	KeyedStateBootstrapFunction.Context	Information available in an invocation of #processElement(Object, Context).

Constructor Summary

Constructors

Constructor	Description
KeyedStateBootstrapFunction()

Method Summary

Modifier and Type	Method	Description
abstract void	processElement(IN value, KeyedStateBootstrapFunction.Context ctx)	Process one element from the input stream.

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

Constructor Detail

KeyedStateBootstrapFunction

public KeyedStateBootstrapFunction()

Method Detail

processElement

public abstract void processElement(IN value,
                                    KeyedStateBootstrapFunction.Context ctx)
                             throws Exception

Process one element from the input stream.

This function can update internal state or set timers using the KeyedStateBootstrapFunction.Context parameter.

Parameters:

value - The input value.

ctx - A KeyedStateBootstrapFunction.Context that allows querying the timestamp of the element and getting a TimerService for registering timers and querying the time. The context is only valid during the invocation of this method, do not store it.

Throws:

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