Package com.google.cloud.datastore

A client to the Google Cloud Datastore.

See: Description

Interface Summary

Interface	Description
Batch	An interface to represent a batch of write operations.
Batch.Response
Datastore	An interface for Google Cloud Datastore.
Datastore.TransactionCallable<T>	A callback for running with a transactional DatastoreReaderWriter.
DatastoreFactory	An interface for Datastore factories.
DatastoreReader	An interface to represent Google Cloud Datastore read operations.
DatastoreReaderWriter	An interface that combines both Google Cloud Datastore read and write operations.
DatastoreWriter	An interface to represent Google Cloud Datastore write operations.
QueryResults<V>	The result of a Google Cloud Datastore query submission.
StructuredQuery.Builder<V>	Interface for StructuredQuery builders.
Transaction	A Google cloud datastore transaction.
Transaction.Response
ValueBuilder<V,P extends Value<V>,B extends ValueBuilder<V,P,B>>	A common interface for Value builders.

Class Summary

Class	Description
BaseDatastoreBatchWriter	Base class for DatastoreBatchWriter.
BaseEntity<K extends IncompleteKey>	A base class for entities (key and properties).
BaseEntity.Builder<K extends IncompleteKey,B extends BaseEntity.Builder<K,B>>
BaseKey	Base class for keys.
BaseKey.Builder<B extends BaseKey.Builder<B>>	Base class for key builders.
Blob	A Google Cloud Datastore Blob.
BlobValue
BlobValue.Builder
BooleanValue
BooleanValue.Builder
Cursor	A Google Cloud Datastore cursor.
DatastoreOptions
DatastoreOptions.Builder
DatastoreOptions.DefaultDatastoreFactory
DatastoreOptions.DefaultDatastoreRpcFactory
DateTime	A Google Cloud Datastore timestamp (represented in micro-seconds).
DateTimeValue
DateTimeValue.Builder
DoubleValue
DoubleValue.Builder
Entity	An entity is the Google Cloud Datastore persistent data object for a specific key.
Entity.Builder
EntityQuery	An implementation of a Google Cloud Datastore entity query that can be constructed by providing all the specific query elements.
EntityQuery.Builder	A EntityQuery builder for queries that return Entity results.
EntityValue
EntityValue.Builder
FullEntity<K extends IncompleteKey>	A full entity is a BaseEntity that holds all the properties associated with a Datastore entity (as opposed to ProjectionEntity).
FullEntity.Builder<K extends IncompleteKey>
GqlQuery<V>	A Google Cloud Datastore GQL query.
GqlQuery.Builder<V>	A GQL query builder.
IncompleteKey	An incomplete key (without a name or id).
IncompleteKey.Builder
Key	A key that is guaranteed to be complete and could be used to reference a Google Cloud Datastore Entity.
Key.Builder
KeyFactory	A helper for creating keys for a specific Datastore, using its associated projectId and namespace.
KeyQuery	An implementation of a Google Cloud Datastore key-only query that can be constructed by providing all the specific query elements.
KeyQuery.Builder	A KeyQuery builder for queries that return Key results.
KeyValue
KeyValue.Builder
LatLng	A Google Cloud Datastore LatLng (represented by latitude and longitude in degrees).
LatLngValue
LatLngValue.Builder
ListValue	A Google Cloud Datastore list value.
ListValue.Builder
LongValue
LongValue.Builder
NullValue
NullValue.Builder
PathElement	Represents a single element in a key's path.
ProjectionEntity	A projection entity is a result of a Google Cloud Datastore projection query.
ProjectionEntity.Builder
ProjectionEntityQuery	An implementation of a Google Cloud Datastore projection entity query that can be constructed by providing all the specific query elements.
ProjectionEntityQuery.Builder	A ProjectionEntityQuery builder for queries that return ProjectionEntity results.
Query<V>	A Google Cloud Datastore query.
Query.ResultType<V>	This class represents the expected type of the result.
RawValue
RawValue.Builder
ReadOption	Specifies options for read operations in Datastore, namely getting/fetching entities and running queries.
ReadOption.EventualConsistency	Specifies eventual consistency for reads from Datastore.
StringValue
StringValue.Builder
StructuredQuery<V>	An implementation of a Google Cloud Datastore Query that can be constructed by providing all the specific query elements.
StructuredQuery.CompositeFilter	A class representing a filter composed of a combination of other filters.
StructuredQuery.Filter
StructuredQuery.OrderBy
StructuredQuery.PropertyFilter	A class representing a filter based on a single property or ancestor.
Value<V>	Base class for all Google Cloud Datastore value types.

Enum Summary

Enum	Description
StructuredQuery.OrderBy.Direction
ValueType	The type of a Datastore property.

Exception Summary

Exception	Description
DatastoreException	Datastore service exception.

Package com.google.cloud.datastore Description

A client to the Google Cloud Datastore.

Here's a simple usage example for using google-cloud from App/Compute Engine. This example shows how to create a Datastore entity. For the complete source code see CreateEntity.java.

 Datastore datastore = DatastoreOptions.defaultInstance().service();
 KeyFactory keyFactory = datastore.newKeyFactory().kind("keyKind");
 Key key = keyFactory.newKey("keyName");
 Entity entity = Entity.builder(key)
     .set("name", "John Doe")
     .set("age", 30)
     .set("access_time", DateTime.now())
     .build();
 datastore.put(entity);
  

This second example shows how to get and update a Datastore entity if it exists. For the complete source code see UpdateEntity.java.

 Datastore datastore = DatastoreOptions.defaultInstance().service();
 KeyFactory keyFactory = datastore.newKeyFactory().kind("keyKind");
 Key key = keyFactory.newKey("keyName");
 Entity entity = datastore.get(key);
 if (entity != null) {
   System.out.println("Updating access_time for " + entity.getString("name"));
   entity = Entity.builder(entity)
       .set("access_time", DateTime.now())
       .build();
   datastore.update(entity);
 } 

When using google-cloud from outside of App/Compute Engine, you have to specify a project ID and provide credentials.

See Also:

Google Cloud Datastore