com.google.cloud.datastore

Interface Batch

All Superinterfaces:

DatastoreBatchWriter, DatastoreWriter

@NotThreadSafe
public interface Batch
extends DatastoreBatchWriter

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.newBuilder(key2).set("name", "John").build();
 entity1 = Entity.newBuilder(entity1).clear().setNull("bla").build();
 Entity entity3 = Entity.newBuilder(key3).set("title", "title").build();
 batch.update(entity1);
 batch.add(entity2, entity3);
 batch.submit();
 

WARNING: This class maintains an internal state in terms of LinkedHashMap and LinkedHashSet which gets updated on every method call performing CRUD operations to record the mutations. Since LinkedHashMap is not thread safe as per its documentation, This class too should not be treated as a thread safe class.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	Batch.Response

Method Summary

Modifier and Type	Method and Description
List<Entity>	add(FullEntity<?>... entities) Datastore add operation: inserts the provided entities.
Entity	add(FullEntity<?> entity) Datastore add operation: inserts the provided entity.
Datastore	getDatastore() Returns the batch associated Datastore.
Batch.Response	submit() Submit the batch to the Datastore.

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

addWithDeferredIdAllocation, delete, isActive, put, put, putWithDeferredIdAllocation, update

Method Detail

add

Entity add(FullEntity<?> entity)

Datastore add operation: inserts the provided entity. This method will automatically allocate an id if necessary. If entity has a complete key and was already marked for deletion in this writer, the operation will be changed to DatastoreBatchWriter.put(com.google.cloud.datastore.FullEntity<?>).

If an entity for entity.getKey() does not exists, entity is inserted. Otherwise, submit() will throw a DatastoreException with BaseServiceException.getReason() equal to "ALREADY_EXISTS".

Specified by:

add in interface DatastoreBatchWriter

Specified by:

add in interface DatastoreWriter

Parameters:

entity - the entity to add

Returns:

an Entity with the same properties and a key that is either newly allocated or the same one if key is already complete

add

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

Datastore add operation: inserts the provided entities. 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 DatastoreBatchWriter.put(com.google.cloud.datastore.FullEntity<?>).

If none of entities' keys exist, all entities are inserted. If any of entities' keys already exists, submit() will throw a DatastoreException with BaseServiceException.getReason() equal to "ALREADY_EXISTS". All entities in entities whose key did not exist are inserted.

Specified by:

add in interface DatastoreBatchWriter

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

See Also:

DatastoreWriter.add(FullEntity)

submit

Batch.Response submit()

Submit the batch to the Datastore.

Throws:

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

getDatastore

Datastore getDatastore()

Returns the batch associated Datastore.