How to give kind name in DatastoreIO.v1.write - google-cloud-dataflow

Question

I am trying to read from a kind in google datastore and apply some transformations and write back to another kind. I am using google dataflow to achieve this. While reading from Datastore, we are able to give Kind. But not able to give Kind while writing. How to achieve this.

Answer 1

EDIT: Oops, I just noticed you were asking for Java. DatastoreIO.v1.write looks at the java equivalent of WriteToDatastore for me, in which case you have to set up your entity (including kind) in the previous step. Check out CreateEntityFn in this example. https://github.com/mbrukman/apache-beam/blob/master/examples/java/src/main/java/org/apache/beam/examples/cookbook/DatastoreWordCount.java#L197
ORIGINAL:
This is how I do it
import apache_beam
from apache_beam.io.gcp.datastore.v1.datastoreio import WriteToDatastore
from google.cloud.proto.datastore.v1 import entity_pb2
from googledatastore import helper
class MakeEntity(object):
def __init__(self, project):
self._project = project
def make(self, element):
try:
entity = entity_pb2.Entity()
helper.add_key_path(entity.key, 'EntityKind', element['id'])
helper.add_properties(entity, {
"created": datetime.datetime.now(),
"email": unicode(element['email'],
"count": int(element['count'],
"amount": float(element['amount'],
})
return entity
except:
logging.error(traceback.format_exc())
raise
def build_pipeline(project, pipeline_options):
p = apache_beam.Pipeline(options=pipeline_options)
_ = \
(p
# other transforms
| 'create entity' >> apache_beam.Map(MakeEntity(project=project).make)
| 'write to datastore' >> WriteToDatastore(project=project))
return p
Edit #2: I adjusted your code to more closely follow the example I linked to. Hopefully this works
public class ModifyEntityKindFn extends DoFn<Entity, Entity> {
#ProcessElement
public void processElement(ProcessContext context) {
Key.Builder keyBuilder = makeKey(NEW_KIND, inputEntity.getKey());
keyBuilder.getPartitionIdBuilder().setNamespaceId(NEW_NAMESPACE);
Entity.Builder entityBuilder = Entity.newBuilder().setKey(keyBuilder.build());
entityBuilder.getMutableProperties().put("content", makeValue(context.element()).build());
context.output(entityBuilder.build());
}
}