org.apache.beam.sdk.transforms

Annotation Type DoFn.StartBundle

@Documented
 @Retention(value=RUNTIME)
 @Target(value=METHOD)
public static @interface DoFn.StartBundle

Annotation for the method to use to prepare an instance for processing a batch of elements. The method annotated with this must satisfy the following constraints:

• If one of the parameters is of type DoFn.StartBundleContext, then it will be passed a context object for the current execution.
• If one of the parameters is of type DoFn.BundleFinalizer, then it will be passed a mechanism to register a callback that will be invoked after the runner successfully commits the output of this bundle. See Apache Beam Portability API: How to Finalize Bundles for further details.