com.google.cloud.datastore

Interface Batch

public interface Batch

An interface to represent a batch of write operations. Any write operation that is applied on a batch will only be sent to the Datastore upon submit(). A usage example:

 Entity entity1 = datastore.get(key1);
 Batch batch = datastore.newBatch();
 Entity entity2 = Entity.builder(key2).set("name", "John").build();
 entity1 = Entity.builder(entity1).clear().setNull("bla").build();
 Entity entity3 = Entity.builder(key3).set("title", "title").build();
 batch.update(entity1);
 batch.add(entity2, entity3);
 batch.submit();
  

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	Batch.Response

Method Summary

Methods

Modifier and Type	Method and Description
boolean	active() Returns true if still active (write operations were not sent to the Datastore).
List<Entity>	add(FullEntity<?>... entity) Datastore add operation.
void	addWithDeferredIdAllocation(FullEntity<?>... entity) Datastore add operation.
Datastore	datastore() Returns the batch associated Datastore.
void	delete(Key... key) A datastore delete operation.
void	put(Entity... entity) A Datastore put (a.k.a upsert) operation.
Batch.Response	submit() Submit the batch to the Datastore.
void	update(Entity... entity) A Datastore update operation.

Methods inherited from interface com.google.cloud.datastore.DatastoreWriter

add

Method Detail

submit

Batch.Response submit()

Submit the batch to the Datastore.

Throws:

DatastoreException - if there was any failure or if batch is not longer active

datastore

Datastore datastore()

Returns the batch associated Datastore.

addWithDeferredIdAllocation

void addWithDeferredIdAllocation(FullEntity<?>... entity)

Datastore add operation. This method will also allocate id for any entity with an incomplete key. As oppose to DatastoreWriter.add(FullEntity), this method will defer any necessary id allocation to submit time.

Throws:

IllegalArgumentException - if any of the given entities is missing a key

DatastoreException - if a given entity with a complete key was already added to this writer or if not active

add

List<Entity> add(FullEntity<?>... entity)

Datastore add operation. This method will automatically allocate id for any entity with an incomplete key. For entities with complete keys that were marked for deletion in this writer the operation will be changed to put(com.google.cloud.datastore.Entity...).

Specified by:

add in interface DatastoreWriter

Returns:

a list of Entity ordered by input with the same properties and a key that is either newly allocated or the same one if was already complete

Throws:

DatastoreException - if a given entity with the same complete key was already added to this writer, if writer is not active or if id allocation for an entity with an incomplete key failed.

See Also:

DatastoreWriter.add(FullEntity)

update

void update(Entity... entity)

A Datastore update operation. The operation will fail if an entity with the same key does not already exist. This operation will be converted to put(com.google.cloud.datastore.Entity...) operation for entities that were already added or put in this writer

Specified by:

update in interface DatastoreWriter

Throws:

DatastoreException - if an entity is marked for deletion in this writer or if not active

delete

void delete(Key... key)

A datastore delete operation. It is OK request a deletion of a non-existing entity. This operation will also remove from this batch any prior writes for entities with the same keys

Specified by:

delete in interface DatastoreWriter

Throws:

DatastoreException - if not active

put

void put(Entity... entity)

A Datastore put (a.k.a upsert) operation. The operation will add or modify the entities. This operation will also remove from this writer any prior writes for the same entities.

Specified by:

put in interface DatastoreWriter

Throws:

DatastoreException - if not active

active

boolean active()

Returns true if still active (write operations were not sent to the Datastore).