org.apache.beam.sdk.extensions.jackson

Class ParseJsons<OutputT>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PCollection<java.lang.String>,PCollection<OutputT>>

org.apache.beam.sdk.extensions.jackson.ParseJsons<OutputT>

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

public class ParseJsons<OutputT>
extends PTransform<PCollection<java.lang.String>,PCollection<OutputT>>

PTransform for parsing JSON Strings. Parse PCollection of Strings in JSON format into a PCollection of objects represented by those JSON Strings using Jackson.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	ParseJsons.ParseJsonsWithFailures<FailureT> A PTransform that adds exception handling to ParseJsons.

Field Summary

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

name, resourceHints

Method Summary

Modifier and Type	Method and Description
<NewFailureT> ParseJsons.ParseJsonsWithFailures<NewFailureT>	exceptionsInto(TypeDescriptor<NewFailureT> failureTypeDescriptor) Returns a new ParseJsons.ParseJsonsWithFailures transform that catches exceptions raised while parsing elements, with the given type descriptor used for the failure collection but the exception handler yet to be specified using ParseJsons.ParseJsonsWithFailures.exceptionsVia(ProcessFunction).
ParseJsons.ParseJsonsWithFailures<KV<java.lang.String,java.util.Map<java.lang.String,java.lang.String>>>	exceptionsVia() Returns a new ParseJsons.ParseJsonsWithFailures transform that catches exceptions raised while parsing elements, passing the raised exception instance and the input element being processed through the default exception handler DefaultExceptionAsMapHandler and emitting the result to a failure collection.
<FailureT> ParseJsons.ParseJsonsWithFailures<FailureT>	exceptionsVia(InferableFunction<WithFailures.ExceptionElement<java.lang.String>,FailureT> exceptionHandler) Returns a new ParseJsons.ParseJsonsWithFailures transform that catches exceptions raised while parsing elements, passing the raised exception instance and the input element being processed through the given exceptionHandler and emitting the result to a failure collection.
PCollection<OutputT>	expand(PCollection<java.lang.String> input) Override this method to specify how this PTransform should be expanded on the given InputT.
static <OutputT> ParseJsons<OutputT>	of(java.lang.Class<? extends OutputT> outputClass) Creates a ParseJsons PTransform that will parse JSON Strings into a PCollection<OutputT> using a Jackson ObjectMapper.
ParseJsons<OutputT>	withMapper(ObjectMapper mapper) Use custom Jackson ObjectMapper instead of the default one.

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

of

public static <OutputT> ParseJsons<OutputT> of(java.lang.Class<? extends OutputT> outputClass)

Creates a ParseJsons PTransform that will parse JSON Strings into a PCollection<OutputT> using a Jackson ObjectMapper.

withMapper

public ParseJsons<OutputT> withMapper(ObjectMapper mapper)

Use custom Jackson ObjectMapper instead of the default one.

exceptionsInto

@Experimental(value=WITH_EXCEPTIONS)
public <NewFailureT> ParseJsons.ParseJsonsWithFailures<NewFailureT> exceptionsInto(TypeDescriptor<NewFailureT> failureTypeDescriptor)

Returns a new ParseJsons.ParseJsonsWithFailures transform that catches exceptions raised while parsing elements, with the given type descriptor used for the failure collection but the exception handler yet to be specified using ParseJsons.ParseJsonsWithFailures.exceptionsVia(ProcessFunction).

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

exceptionsVia

@Experimental(value=WITH_EXCEPTIONS)
public <FailureT> ParseJsons.ParseJsonsWithFailures<FailureT> exceptionsVia(InferableFunction<WithFailures.ExceptionElement<java.lang.String>,FailureT> exceptionHandler)

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

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

Example usage:

 WithFailures.Result<PCollection<MyPojo>, KV<String, Map<String, String>>> result =
     json.apply(
         ParseJsons.of(MyPojo.class)
             .exceptionsVia(new WithFailures.ExceptionAsMapHandler<String>() {}));

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

exceptionsVia

@Experimental(value=WITH_EXCEPTIONS)
public ParseJsons.ParseJsonsWithFailures<KV<java.lang.String,java.util.Map<java.lang.String,java.lang.String>>> exceptionsVia()

Returns a new ParseJsons.ParseJsonsWithFailures transform that catches exceptions raised while parsing elements, passing the raised exception instance and the input element being processed through the default exception handler DefaultExceptionAsMapHandler and emitting the result to a failure collection.

See DefaultExceptionAsMapHandler for more details about default handler behavior.

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

Example usage:

 WithFailures.Result<PCollection<MyPojo>, KV<String, Map<String, String>>> result =
     json.apply(
         ParseJsons.of(MyPojo.class)
             .exceptionsVia());

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

expand

public PCollection<OutputT> expand(PCollection<java.lang.String> 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<java.lang.String>,PCollection<OutputT>>