org.apache.beam.sdk.extensions.jackson

Class AsJsons.AsJsonsWithFailures<FailureT>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PCollection<InputT>,WithFailures.Result<PCollection<java.lang.String>,FailureT>>

org.apache.beam.sdk.extensions.jackson.AsJsons.AsJsonsWithFailures<FailureT>

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

Enclosing class:

AsJsons<InputT>

public class AsJsons.AsJsonsWithFailures<FailureT>
extends PTransform<PCollection<InputT>,WithFailures.Result<PCollection<java.lang.String>,FailureT>>

A PTransform that adds exception handling to AsJsons.

See Also:

Serialized Form

Field Summary

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

name, resourceHints

Method Summary

Modifier and Type	Method and Description
AsJsons.AsJsonsWithFailures<FailureT>	exceptionsVia(ProcessFunction<WithFailures.ExceptionElement<InputT>,FailureT> exceptionHandler) Returns a new AsJsons.AsJsonsWithFailures transform that catches exceptions raised while writing JSON 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<java.lang.String>,FailureT>	expand(PCollection<InputT> input) Override this method to specify how this PTransform should be expanded on the given InputT.

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

compose, compose, getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, getResourceHints, populateDisplayData, setResourceHints, toString, validate

Methods inherited from class java.lang.Object

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

Method Detail

exceptionsVia

public AsJsons.AsJsonsWithFailures<FailureT> exceptionsVia(ProcessFunction<WithFailures.ExceptionElement<InputT>,FailureT> exceptionHandler)

Returns a new AsJsons.AsJsonsWithFailures transform that catches exceptions raised while writing JSON elements, passing the raised exception instance and the input element being processed through the given exceptionHandler and emitting the result to a failure collection. It is supposed to be used along with AsJsons.exceptionsInto(TypeDescriptor) and get lambda function as exception handler.

See WithFailures documentation for usage patterns of the returned WithFailures.Result.

Example usage:

 WithFailures.Result<PCollection<String>, KV<MyPojo, Map<String, String>>> result =
     pojos.apply(
         AsJsons.of(MyPojo.class)
             .exceptionsInto(
                 TypeDescriptors.kvs(
                     TypeDescriptor.of(MyPojo.class), TypeDescriptors.strings()))
             .exceptionsVia(
                 f -> KV.of(f.element(), f.exception().getClass().getCanonicalName())));

 PCollection<String> output = result.output(); // valid json elements
 PCollection<KV<MyPojo, Map<String, String>>> failures = result.failures();
 

expand

public WithFailures.Result<PCollection<java.lang.String>,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<java.lang.String>,FailureT>>