Package 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.

  • Method Details

    • 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:

    • 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.