Class DatastoreHelper (2.7.0)

Version 2.7.0

• 2.24.1 (latest)
• 2.23.0
• 2.22.0
• 2.21.3
• 2.20.2
• 2.19.2
• 2.18.5
• 2.17.6

public final class DatastoreHelper

Helper methods for Datastore.

Inheritance

java.lang.Object > DatastoreHelper

Inherited Members

Object.clone()

Object.equals(Object)

Object.finalize()

Object.getClass()

Object.hashCode()

Object.notify()

Object.notifyAll()

Object.toString()

Object.wait()

Object.wait(long)

Object.wait(long,int)

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
value	Value

Returns

Type	Description
boolean	the boolean contained in value

getByteString(Value value)

public static ByteString getByteString(Value value)

Parameter

Name	Description
value	Value

Returns

Type	Description
ByteString	the blob contained in value

getDatastoreFromEnv()

public static Datastore getDatastoreFromEnv()

See Also: #getOptionsFromEnv()

Returns

Type	Description
Datastore

Exceptions

Type	Description
GeneralSecurityException
IOException

getDouble(Value value)

public static double getDouble(Value value)

Parameter

Name	Description
value	Value

Returns

Type	Description
double	the double contained in value

getEntity(Value value)

public static Entity getEntity(Value value)

Parameter

Name	Description
value	Value

Returns

Type	Description
Entity	the entity contained in value

getKey(Value value)

public static Key getKey(Value value)

Parameter

Name	Description
value	Value

Returns

Type	Description
Key	the key contained in value

getKeyComparator()

public static Comparator<Key> getKeyComparator()

Returns

Type	Description
Comparator<Key>

getList(Value value)

public static List<Value> getList(Value value)

Parameter

Name	Description
value	Value

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
value	Value

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:

1. No credentials (if the DATASTORE_EMULATOR_HOST environment variable is set)
2. Service Account specified by the DATASTORE_SERVICE_ACCOUNT and DATASTORE_PRIVATE_KEY_FILE environment variables
3. Google Application Default as described here.

Returns

Type	Description
DatastoreOptions.Builder

Exceptions

Type	Description
GeneralSecurityException
IOException

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()

Gets a QuerySplitter.

The returned QuerySplitter#getSplits cannot accept a query that contains inequality filters, a sort filter, or a missing kind.

Returns

Type	Description
QuerySplitter

getServiceAccountCredential(String serviceAccountId, String privateKeyFile)

public static Credential getServiceAccountCredential(String serviceAccountId, String privateKeyFile)

Constructs credentials for the given account and key.

Parameters

Name	Description
serviceAccountId	String service account ID (typically an e-mail address).
privateKeyFile	String the file name from which to get the private key.

Returns

Type	Description
com.google.api.client.auth.oauth2.Credential	valid credentials or null

Exceptions

Type	Description
GeneralSecurityException
IOException

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
serviceAccountId	String service account ID (typically an e-mail address).
privateKeyFile	String the file name from which to get the private key.
serviceAccountScopes	Collection<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

Exceptions

Type	Description
GeneralSecurityException
IOException

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
serviceAccountId	String service account ID (typically an e-mail address).
privateKey	PrivateKey the private key for the given account.
serviceAccountScopes	Collection<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

Exceptions

Type	Description
GeneralSecurityException
IOException

getString(Value value)

public static String getString(Value value)

Parameter

Name	Description
value	Value

Returns

Type	Description
String	the string contained in value

getTimestamp(Value value)

public static long getTimestamp(Value value)

Parameter

Name	Description
value	Value

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
ancestor	Key

Returns

Type	Description
Filter.Builder

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
subfilters	Filter[]

Returns

Type	Description
Filter.Builder

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.

Parameter

Name	Description
subfilters	Iterable<Filter>

Returns

Type	Description
Filter.Builder

makeDelete(Key key)

public static Mutation.Builder makeDelete(Key key)

Parameter

Name	Description
key	Key the key of the entity to delete

Returns

Type	Description
Mutation.Builder	a mutation that will delete an entity

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.

Parameters

Name	Description
property	String
operator	PropertyFilter.Operator
value	Value

Returns

Type	Description
Filter.Builder

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.

Parameters

Name	Description
property	String
operator	PropertyFilter.Operator
value	Value.Builder

Returns

Type	Description
Filter.Builder

makeInsert(Entity entity)

public static Mutation.Builder makeInsert(Entity entity)

Parameter

Name	Description
entity	Entity the entity to insert

Returns

Type	Description
Mutation.Builder	a mutation that will insert an entity

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
elements	Object[]

Returns

Type	Description
Key.Builder

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.

Parameters

Name	Description
property	String
direction	PropertyOrder.Direction

Returns

Type	Description
PropertyOrder.Builder

makePropertyReference(String propertyName)

public static PropertyReference.Builder makePropertyReference(String propertyName)

Make a property reference for use in a query.

Parameter

Name	Description
propertyName	String

Returns

Type	Description
PropertyReference.Builder

makeUpdate(Entity entity)

public static Mutation.Builder makeUpdate(Entity entity)

Parameter

Name	Description
entity	Entity the entity to update

Returns

Type	Description
Mutation.Builder	a mutation that will update an entity

makeUpsert(Entity entity)

public static Mutation.Builder makeUpsert(Entity entity)

Parameter

Name	Description
entity	Entity the entity to upsert

Returns

Type	Description
Mutation.Builder	a mutation that will upsert an entity

makeValue(boolean value)

public static Value.Builder makeValue(boolean value)

Make a boolean value.

Parameter

Name	Description
value	boolean

Returns

Type	Description
Value.Builder

makeValue(Entity entity)

public static Value.Builder makeValue(Entity entity)

Make an entity value.

Parameter

Name	Description
entity	Entity

Returns

Type	Description
Value.Builder

makeValue(Entity.Builder entity)

public static Value.Builder makeValue(Entity.Builder entity)

Make a entity value.

Parameter

Name	Description
entity	Entity.Builder

Returns

Type	Description
Value.Builder

makeValue(Key key)

public static Value.Builder makeValue(Key key)

Make a key value.

Parameter

Name	Description
key	Key

Returns

Type	Description
Value.Builder

makeValue(Key.Builder key)

public static Value.Builder makeValue(Key.Builder key)

Make a key value.

Parameter

Name	Description
key	Key.Builder

Returns

Type	Description
Value.Builder

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.

Parameters

Name	Description
value1	Value
value2	Value
rest	Value[]

Returns

Type	Description
Value.Builder

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.

Parameters

Name	Description
value1	Value.Builder
value2	Value.Builder
rest	Builder[]

Returns

Type	Description
Value.Builder

makeValue(ByteString blob)

public static Value.Builder makeValue(ByteString blob)

Make a ByteString value.

Parameter

Name	Description
blob	ByteString

Returns

Type	Description
Value.Builder

makeValue(LatLng value)

public static Value.Builder makeValue(LatLng value)

Makes a GeoPoint value.

Parameter

Name	Description
value	com.google.type.LatLng

Returns

Type	Description
Value.Builder

makeValue(LatLng.Builder value)

public static Value.Builder makeValue(LatLng.Builder value)

Makes a GeoPoint value.

Parameter

Name	Description
value	com.google.type.LatLng.Builder

Returns

Type	Description
Value.Builder

makeValue(double value)

public static Value.Builder makeValue(double value)

Make a floating point value.

Parameter

Name	Description
value	double

Returns

Type	Description
Value.Builder

makeValue(Iterable<Value> values)

public static Value.Builder makeValue(Iterable<Value> values)

Make an array value containing the specified values.

Parameter

Name	Description
values	Iterable<Value>

Returns

Type	Description
Value.Builder

makeValue(String value)

public static Value.Builder makeValue(String value)

Make a string value.

Parameter

Name	Description
value	String

Returns

Type	Description
Value.Builder

makeValue(Date date)

public static Value.Builder makeValue(Date date)

Make a timestamp value given a date.

Parameter

Name	Description
date	Date

Returns

Type	Description
Value.Builder

makeValue(long key)

public static Value.Builder makeValue(long key)

Make an integer value.

Parameter

Name	Description
key	long

Returns

Type	Description
Value.Builder

toDate(Value value)

public static Date toDate(Value value)

Convert a timestamp value into a Date clipping off the microseconds.

Parameter

Name	Description
value	Value a timestamp value to convert

Returns

Type	Description
Date	the resulting Date