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Class DatastoreHelper (2.32.2)
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public final class DatastoreHelper
Static Fields
KEY_PROPERTY_NAME
public static final String KEY_PROPERTY_NAME
The property used in the Datastore to get the key of the entity. *
Field Value
Type Description
String
LOCAL_HOST_ENV_VAR
public static final String LOCAL_HOST_ENV_VAR
Name of the environment variable used to set the local host.
Field Value
Type Description
String
PRIVATE_KEY_FILE_ENV_VAR
public static final String PRIVATE_KEY_FILE_ENV_VAR
Name of the environment variable used to set the private key file.
Field Value
Type Description
String
PROJECT_ID_ENV_VAR
public static final String PROJECT_ID_ENV_VAR
Name of the environment variable used to set the project ID.
Field Value
Type Description
String
SCATTER_PROPERTY_NAME
public static final String SCATTER_PROPERTY_NAME
The property used in the Datastore to give us a random distribution. *
Field Value
Type Description
String
SERVICE_ACCOUNT_ENV_VAR
public static final String SERVICE_ACCOUNT_ENV_VAR
Name of the environment variable used to set the service account.
Field Value
Type Description
String
Static Methods
getBoolean(Value value)
public static boolean getBoolean ( Value value )
Parameter
Name Description
valueValue
Returns
Type Description
boolean the boolean contained in value
getByteString(Value value)
public static ByteString getByteString ( Value value )
Parameter
Name Description
valueValue
Returns
Type Description
ByteString the blob contained in value
getDatastoreFromEnv()
public static Datastore getDatastoreFromEnv ()
getDouble(Value value)
public static double getDouble ( Value value )
Parameter
Name Description
valueValue
Returns
Type Description
double the double contained in value
getEntity(Value value)
public static Entity getEntity ( Value value )
Parameter
Name Description
valueValue
Returns
Type Description
Entity the entity contained in value
getKey(Value value)
public static Key getKey ( Value value )
Parameter
Name Description
valueValue
Returns
Type Description
Key the key contained in value
getKeyComparator()
public static Comparator<Key> getKeyComparator ()
getList(Value value)
public static List<Value> getList ( Value value )
Parameter
Name Description
valueValue
Returns
Type Description
List <Value >the array contained in value as a list.
getLong(Value value)
public static long getLong ( Value value )
Parameter
Name Description
valueValue
Returns
Type Description
long the long contained in value
getOptionsFromEnv()
public static DatastoreOptions . Builder getOptionsFromEnv ()
Constructs a Datastore from environment variables and/or the Compute Engine metadata
server.
The project ID is determined from, in order of preference:
DATASTORE_PROJECT_ID environment variable
Compute Engine
Credentials are taken from, in order of preference:
No credentials (if the DATASTORE_EMULATOR_HOST environment variable is set)
Service Account specified by the DATASTORE_SERVICE_ACCOUNT and DATASTORE_PRIVATE_KEY_FILE
environment variables
Google Application Default as described here .
getProjectIdFromComputeEngine()
public static String getProjectIdFromComputeEngine ()
Gets the project ID from the Compute Engine metadata server. Returns null if the
project ID cannot be determined (because, for instance, the code is not running on Compute
Engine).
Returns
Type Description
String
getQuerySplitter()
public static QuerySplitter getQuerySplitter ()
getServiceAccountCredential(String serviceAccountId, String privateKeyFile)
public static Credential getServiceAccountCredential ( String serviceAccountId , String privateKeyFile )
Constructs credentials for the given account and key.
Parameters
Name Description
serviceAccountIdString service account ID (typically an e-mail address).
privateKeyFileString the file name from which to get the private key.
Returns
Type Description
com.google.api.client.auth.oauth2.Credential valid credentials or null
getServiceAccountCredential(String serviceAccountId, String privateKeyFile, Collection<String> serviceAccountScopes)
public static Credential getServiceAccountCredential ( String serviceAccountId , String privateKeyFile , Collection<String> serviceAccountScopes )
Constructs credentials for the given account and key file.
Parameters
Name Description
serviceAccountIdString service account ID (typically an e-mail address).
privateKeyFileString the file name from which to get the private key.
serviceAccountScopesCollection <String >Collection of OAuth scopes to use with the the service account flow
or null if not.
Returns
Type Description
com.google.api.client.auth.oauth2.Credential valid credentials or null
getServiceAccountCredential(String serviceAccountId, PrivateKey privateKey, Collection<String> serviceAccountScopes)
public static Credential getServiceAccountCredential ( String serviceAccountId , PrivateKey privateKey , Collection<String> serviceAccountScopes )
Constructs credentials for the given account and key.
Parameters
Name Description
serviceAccountIdString service account ID (typically an e-mail address).
privateKeyPrivateKey the private key for the given account.
serviceAccountScopesCollection <String >Collection of OAuth scopes to use with the the service account flow
or null if not.
Returns
Type Description
com.google.api.client.auth.oauth2.Credential valid credentials or null
getString(Value value)
public static String getString ( Value value )
Parameter
Name Description
valueValue
Returns
Type Description
String the string contained in value
getTimestamp(Value value)
public static long getTimestamp ( Value value )
Parameter
Name Description
valueValue
Returns
Type Description
long the timestamp in microseconds contained in value
makeAncestorFilter(Key ancestor)
public static Filter . Builder makeAncestorFilter ( Key ancestor )
Makes an ancestor filter.
Parameter
Name Description
ancestorKey
makeAndFilter(Filter[] subfilters)
public static Filter . Builder makeAndFilter ( Filter [] subfilters )
Make a composite filter from the given sub-filters using AND to combine filters.
Parameter
Name Description
subfiltersFilter []
makeAndFilter(Iterable<Filter> subfilters)
public static Filter . Builder makeAndFilter ( Iterable<Filter> subfilters )
Make a composite filter from the given sub-filters using AND to combine filters.
makeDelete(Key key)
public static Mutation . Builder makeDelete ( Key key )
Parameter
Name Description
keyKey the key of the entity to delete
makeFilter(String property, PropertyFilter.Operator operator, Value value)
public static Filter . Builder makeFilter ( String property , PropertyFilter . Operator operator , Value value )
Make a filter on a property for use in a query.
makeFilter(String property, PropertyFilter.Operator operator, Value.Builder value)
public static Filter . Builder makeFilter ( String property , PropertyFilter . Operator operator , Value . Builder value )
Make a filter on a property for use in a query.
makeInsert(Entity entity)
public static Mutation . Builder makeInsert ( Entity entity )
Parameter
Name Description
entityEntity the entity to insert
makeKey(Object[] elements)
public static Key . Builder makeKey ( Object [] elements )
Make a key from the specified path of kind/id-or-name pairs and/or Keys.
The id-or-name values must be either String, Long, Integer or Short.
The last id-or-name value may be omitted, in which case an entity without an id is created
(for use with automatic id allocation).
The PartitionIds of all Keys in the path must be equal. The returned Key.Builder will use
this PartitionId.
Parameter
Name Description
elementsObject []
makeOrder(String property, PropertyOrder.Direction direction)
public static PropertyOrder . Builder makeOrder ( String property , PropertyOrder . Direction direction )
Make a sort order for use in a query.
makePropertyReference(String propertyName)
public static PropertyReference . Builder makePropertyReference ( String propertyName )
Make a property reference for use in a query.
Parameter
Name Description
propertyNameString
makeUpdate(Entity entity)
public static Mutation . Builder makeUpdate ( Entity entity )
Parameter
Name Description
entityEntity the entity to update
makeUpsert(Entity entity)
public static Mutation . Builder makeUpsert ( Entity entity )
Parameter
Name Description
entityEntity the entity to upsert
makeValue(boolean value)
public static Value . Builder makeValue ( boolean value )
Parameter
Name Description
valueboolean
makeValue(Entity entity)
public static Value . Builder makeValue ( Entity entity )
Parameter
Name Description
entityEntity
makeValue(Entity.Builder entity)
public static Value . Builder makeValue ( Entity . Builder entity )
makeValue(Key key)
public static Value . Builder makeValue ( Key key )
Parameter
Name Description
keyKey
makeValue(Key.Builder key)
public static Value . Builder makeValue ( Key . Builder key )
makeValue(Value value1, Value value2, Value[] rest)
public static Value . Builder makeValue ( Value value1 , Value value2 , Value [] rest )
Make a list value containing the specified values.
makeValue(Value.Builder value1, Value.Builder value2, Value.Builder[] rest)
public static Value . Builder makeValue ( Value . Builder value1 , Value . Builder value2 , Value . Builder [] rest )
Make an array value containing the specified values.
makeValue(ByteString blob)
public static Value . Builder makeValue ( ByteString blob )
makeValue(LatLng value)
public static Value . Builder makeValue ( LatLng value )
Parameter
Name Description
valuecom.google.type.LatLng
makeValue(LatLng.Builder value)
public static Value . Builder makeValue ( LatLng . Builder value )
Parameter
Name Description
valuecom.google.type.LatLng.Builder
makeValue(double value)
public static Value . Builder makeValue ( double value )
Make a floating point value.
Parameter
Name Description
valuedouble
makeValue(Iterable<Value> values)
public static Value . Builder makeValue ( Iterable<Value> values )
Make an array value containing the specified values.
makeValue(String value)
public static Value . Builder makeValue ( String value )
Parameter
Name Description
valueString
makeValue(Date date)
public static Value . Builder makeValue ( Date date )
Make a timestamp value given a date.
Parameter
Name Description
dateDate
makeValue(long key)
public static Value . Builder makeValue ( long key )
Parameter
Name Description
keylong
toDate(Value value)
public static Date toDate ( Value value )
Convert a timestamp value into a Date clipping off the microseconds.
Parameter
Name Description
valueValue a timestamp value to convert
Returns
Type Description
Date the resulting Date
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Last updated 2025-10-30 UTC.
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