public class ToJson<T> extends PTransform<PCollection<T>,PCollection<java.lang.String>>
PTransform
that serializes UTF-8 JSON objects from a Schema
-aware
PCollection (i.e. PCollection.hasSchema()
returns true). JSON format is compatible with
JsonToRow
.
For specifics of JSON serialization see RowJson.RowJsonSerializer
.
annotations, displayData, name, resourceHints
Modifier and Type | Method and Description |
---|---|
PCollection<java.lang.String> |
expand(PCollection<T> rows)
Override this method to specify how this
PTransform should be expanded on the given
InputT . |
static <T> ToJson<T> |
of() |
addAnnotation, compose, compose, getAdditionalInputs, getAnnotations, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, getResourceHints, populateDisplayData, setDisplayData, setResourceHints, toString, validate, validate
public static <T> ToJson<T> of()
public PCollection<java.lang.String> expand(PCollection<T> rows)
PTransform
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).
expand
in class PTransform<PCollection<T>,PCollection<java.lang.String>>