org.apache.flink.streaming.api.scala.function.util

Class ScalaAllWindowFunctionWrapper<IN,OUT,W extends Window>

java.lang.Object

org.apache.flink.streaming.api.scala.function.util.ScalaAllWindowFunctionWrapper<IN,OUT,W>

All Implemented Interfaces:

Serializable, Function, RichFunction, AllWindowFunction<IN,OUT,W>

public final class ScalaAllWindowFunctionWrapper<IN,OUT,W extends Window>
extends Object
implements AllWindowFunction<IN,OUT,W>, RichFunction

A wrapper function that exposes a Scala WindowFunction as a JavaWindow function.

The Scala and Java Window functions differ in their type of "Iterable": - Scala WindowFunction: scala.Iterable - Java WindowFunction: java.lang.Iterable

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ScalaAllWindowFunctionWrapper(AllWindowFunction<IN,OUT,W> func)

Method Summary

Modifier and Type	Method and Description
void	apply(W window, Iterable<IN> input, Collector<OUT> out) Evaluates the window and outputs none or several elements.
void	close() Tear-down method for the user code.
IterationRuntimeContext	getIterationRuntimeContext() Gets a specialized version of the RuntimeContext, which has additional information about the iteration in which the function is executed.
RuntimeContext	getRuntimeContext() Gets the context that contains information about the UDF's runtime, such as the parallelism of the function, the subtask index of the function, or the name of the of the task that executes the function.
void	open(Configuration parameters) Initialization method for the function.
void	setRuntimeContext(RuntimeContext t) Sets the function's runtime context.

Methods inherited from class java.lang.Object

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

Constructor Detail

ScalaAllWindowFunctionWrapper

public ScalaAllWindowFunctionWrapper(AllWindowFunction<IN,OUT,W> func)

Method Detail

apply

public void apply(W window,
                  Iterable<IN> input,
                  Collector<OUT> out)

Description copied from interface: AllWindowFunction

Evaluates the window and outputs none or several elements.

Specified by:

apply in interface AllWindowFunction<IN,OUT,W extends Window>

Parameters:

window - The window that is being evaluated.

input - The elements in the window being evaluated.

out - A collector for emitting elements.

open

public void open(Configuration parameters)

Description copied from interface: RichFunction

Initialization method for the function. It is called before the actual working methods (like map or join) and thus suitable for one time setup work. For functions that are part of an iteration, this method will be invoked at the beginning of each iteration superstep.

The configuration object passed to the function can be used for configuration and initialization. The configuration contains all parameters that were configured on the function in the program composition.

 public class MyMapper extends FilterFunction<String> {
 
     private String searchString;
     
     public void open(Configuration parameters) {
         this.searchString = parameters.getString("foo");
     }
     
     public boolean filter(String value) {
         return value.equals(searchString);
     }
 }
 

By default, this method does nothing.

Specified by:

open in interface RichFunction

Parameters:

parameters - The configuration containing the parameters attached to the contract.

See Also:

Configuration

close

public void close()

Description copied from interface: RichFunction

Tear-down method for the user code. It is called after the last call to the main working methods (e.g. map or join). For functions that are part of an iteration, this method will be invoked after each iteration superstep.

This method can be used for clean up work.

Specified by:

close in interface RichFunction

setRuntimeContext

public void setRuntimeContext(RuntimeContext t)

Description copied from interface: RichFunction

Sets the function's runtime context. Called by the framework when creating a parallel instance of the function.

Specified by:

setRuntimeContext in interface RichFunction

Parameters:

t - The runtime context.

getRuntimeContext

public RuntimeContext getRuntimeContext()

Description copied from interface: RichFunction

Gets the context that contains information about the UDF's runtime, such as the parallelism of the function, the subtask index of the function, or the name of the of the task that executes the function.

The RuntimeContext also gives access to the Accumulators and the DistributedCache.

Specified by:

getRuntimeContext in interface RichFunction

Returns:

The UDF's runtime context.

getIterationRuntimeContext

public IterationRuntimeContext getIterationRuntimeContext()

Description copied from interface: RichFunction

Gets a specialized version of the RuntimeContext, which has additional information about the iteration in which the function is executed. This IterationRuntimeContext is only available if the function is part of an iteration. Otherwise, this method throws an exception.

Specified by:

getIterationRuntimeContext in interface RichFunction

Returns:

The IterationRuntimeContext.