org.apache.beam.sdk.transforms

Class FlatMapElements.FlatMapWithFailures<InputT,OutputT,FailureT>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PCollection<InputT>,WithFailures.Result<PCollection<OutputT>,FailureT>>

org.apache.beam.sdk.transforms.FlatMapElements.FlatMapWithFailures<InputT,OutputT,FailureT>

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

Enclosing class:

FlatMapElements<InputT,OutputT>

@Experimental(value=WITH_EXCEPTIONS)
public static class FlatMapElements.FlatMapWithFailures<InputT,OutputT,FailureT>
extends PTransform<PCollection<InputT>,WithFailures.Result<PCollection<OutputT>,FailureT>>

A PTransform that adds exception handling to FlatMapElements.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.PTransform

name

Method Summary

Modifier and Type	Method and Description
FlatMapElements.FlatMapWithFailures<InputT,OutputT,FailureT>	exceptionsVia(ProcessFunction<WithFailures.ExceptionElement<InputT>,FailureT> exceptionHandler) Returns a new FlatMapElements.FlatMapWithFailures transform that catches exceptions raised while mapping elements, passing the raised exception instance and the input element being processed through the given exceptionHandler and emitting the result to a failure collection.
WithFailures.Result<PCollection<OutputT>,FailureT>	expand(PCollection<InputT> input) Override this method to specify how this PTransform should be expanded on the given InputT.
void	populateDisplayData(DisplayData.Builder builder) Register display data for the given transform or component.

Methods inherited from class org.apache.beam.sdk.transforms.PTransform

compose, compose, getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, toString, validate

Methods inherited from class java.lang.Object

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

Method Detail

exceptionsVia

public FlatMapElements.FlatMapWithFailures<InputT,OutputT,FailureT> exceptionsVia(ProcessFunction<WithFailures.ExceptionElement<InputT>,FailureT> exceptionHandler)

Returns a new FlatMapElements.FlatMapWithFailures transform that catches exceptions raised while mapping elements, passing the raised exception instance and the input element being processed through the given exceptionHandler and emitting the result to a failure collection.

Example usage:

 Result<PCollection<String>, String>> result = words.apply(
     FlatMapElements
         .into(TypeDescriptors.strings())
         // Could throw ArrayIndexOutOfBoundsException
         .via((String line) -> Arrays.asList(Arrays.copyOfRange(line.split(" "), 1, 5)))
         .exceptionsInto(TypeDescriptors.strings())
         .exceptionsVia((ExceptionElement<String> ee) -> ee.exception().getMessage()));
 PCollection<String> output = result.output();
 PCollection<String> failures = result.failures();
 

expand

public WithFailures.Result<PCollection<OutputT>,FailureT> expand(PCollection<InputT> input)

Description copied from class: PTransform

Override this method to specify how this PTransform should be expanded on the given InputT.

NOTE: This method should not be called directly. Instead apply the PTransform should be applied to the InputT using the apply method.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

Specified by:

expand in class PTransform<PCollection<InputT>,WithFailures.Result<PCollection<OutputT>,FailureT>>

populateDisplayData

public void populateDisplayData(DisplayData.Builder builder)

Description copied from class: PTransform

Register display data for the given transform or component.

populateDisplayData(DisplayData.Builder) is invoked by Pipeline runners to collect display data via DisplayData.from(HasDisplayData). Implementations may call super.populateDisplayData(builder) in order to register display data in the current namespace, but should otherwise use subcomponent.populateDisplayData(builder) to use the namespace of the subcomponent.

By default, does not register any display data. Implementors may override this method to provide their own display data.

Specified by:

populateDisplayData in interface HasDisplayData

Overrides:

populateDisplayData in class PTransform<PCollection<InputT>,WithFailures.Result<PCollection<OutputT>,FailureT>>

Parameters:

builder - The builder to populate with display data.

See Also:

HasDisplayData