public interface AsyncDatastoreService extends BaseDatastoreService

An asynchronous version of [DatastoreService](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService). All methods return immediately and provide
[Futures](https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html) as their return values.

The key difference between implementations of [AsyncDatastoreService](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.AsyncDatastoreService) and
implementations of [DatastoreService](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService) is that async implementations do not perform implicit
transaction management. The reason is that implicit transaction management requires automatic
commits of some transactions, and without some sort of callback mechanism there is no way to
determine that a put/get/delete that has been implicitly enrolled in a transaction is complete
and therefore ready to be committed. See [ImplicitTransactionManagementPolicy](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.ImplicitTransactionManagementPolicy) for more
information.

## Implements

[BaseDatastoreService](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.BaseDatastoreService)

## Methods

### allocateIds(@Nullable Key parent, String kind, long num)

    public abstract Future<KeyRange> allocateIds(@Nullable Key parent, String kind, long num)

See [DatastoreService#allocateIds(Key, String, long)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_allocateIds_com_google_appengine_api_datastore_Key_java_lang_String_long_).

| **Parameters** ||
|---|---|
| **Name** | **Description** |
| `parent` | `com.google.appengine.api.datastore.@org.jspecify.annotations.Nullable Key` |
| `kind` | `https://docs.oracle.com/javase/8/docs/api/java/lang/String.html` |
| `num` | `https://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.KeyRange>` |   |

### allocateIds(String kind, long num)

    public abstract Future<KeyRange> allocateIds(String kind, long num)

See [DatastoreService#allocateIds(String, long)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_allocateIds_java_lang_String_long_).

| **Parameters** ||
|---|---|
| **Name** | **Description** |
| `kind` | `https://docs.oracle.com/javase/8/docs/api/java/lang/String.html` |
| `num` | `https://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.KeyRange>` |   |

### beginTransaction()

    public abstract Future<Transaction> beginTransaction()

See [DatastoreService#beginTransaction()](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_beginTransaction__).

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Transaction>` |   |

### beginTransaction(TransactionOptions options)

    public abstract Future<Transaction> beginTransaction(TransactionOptions options)

See [DatastoreService#beginTransaction(TransactionOptions)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_beginTransaction_com_google_appengine_api_datastore_TransactionOptions_).

| **Parameter** ||
|---|---|
| **Name** | **Description** |
| `options` | `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.TransactionOptions` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Transaction>` |   |

### delete(@Nullable Transaction txn, Key\[\] keys)

    public abstract Future<Void> delete(@Nullable Transaction txn, Key[] keys)

See [DatastoreService#delete(Transaction, Iterable)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_delete_com_google_appengine_api_datastore_Transaction_java_lang_Iterable_com_google_appengine_api_datastore_Key__).

| **Parameters** ||
|---|---|
| **Name** | **Description** |
| `txn` | `com.google.appengine.api.datastore.@org.jspecify.annotations.Nullable Transaction` |
| `keys` | `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key[]` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.oracle.com/javase/8/docs/api/java/lang/Void.html>` |   |

### delete(@Nullable Transaction txn, Iterable\<Key\> keys)

    public abstract Future<Void> delete(@Nullable Transaction txn, Iterable<Key> keys)

See [DatastoreService#delete(Transaction, Iterable)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_delete_com_google_appengine_api_datastore_Transaction_java_lang_Iterable_com_google_appengine_api_datastore_Key__).

| **Parameters** ||
|---|---|
| **Name** | **Description** |
| `txn` | `com.google.appengine.api.datastore.@org.jspecify.annotations.Nullable Transaction` |
| `keys` | `https://docs.oracle.com/javase/8/docs/api/java/lang/Iterable.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key>` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.oracle.com/javase/8/docs/api/java/lang/Void.html>` |   |

### delete(Key\[\] keys)

    public abstract Future<Void> delete(Key[] keys)

See [DatastoreService#delete(Key...)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_delete_).

| **Parameter** ||
|---|---|
| **Name** | **Description** |
| `keys` | `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key[]` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.oracle.com/javase/8/docs/api/java/lang/Void.html>` |   |

### delete(Iterable\<Key\> keys)

    public abstract Future<Void> delete(Iterable<Key> keys)

See [DatastoreService#delete(Iterable)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_delete_java_lang_Iterable_com_google_appengine_api_datastore_Key__).

| **Parameter** ||
|---|---|
| **Name** | **Description** |
| `keys` | `https://docs.oracle.com/javase/8/docs/api/java/lang/Iterable.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key>` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.oracle.com/javase/8/docs/api/java/lang/Void.html>` |   |

### get(@Nullable Transaction txn, Key key)

    public abstract Future<Entity> get(@Nullable Transaction txn, Key key)

See [DatastoreService#get(Transaction, Key)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_get_com_google_appengine_api_datastore_Transaction_com_google_appengine_api_datastore_Key_).

| **Parameters** ||
|---|---|
| **Name** | **Description** |
| `txn` | `com.google.appengine.api.datastore.@org.jspecify.annotations.Nullable Transaction` |
| `key` | `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Entity>` |   |

### get(@Nullable Transaction txn, Iterable\<Key\> keys)

    public abstract Future<Map<Key,Entity>> get(@Nullable Transaction txn, Iterable<Key> keys)

See [DatastoreService#get(Transaction, Iterable)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_get_com_google_appengine_api_datastore_Transaction_java_lang_Iterable_com_google_appengine_api_datastore_Key__).

| **Parameters** ||
|---|---|
| **Name** | **Description** |
| `txn` | `com.google.appengine.api.datastore.@org.jspecify.annotations.Nullable Transaction` |
| `keys` | `https://docs.oracle.com/javase/8/docs/api/java/lang/Iterable.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key>` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.oracle.com/javase/8/docs/api/java/util/Map.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key,https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Entity>>` |   |

### get(Key key)

    public abstract Future<Entity> get(Key key)

See [DatastoreService#get(Key)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_get_com_google_appengine_api_datastore_Key_).

| **Parameter** ||
|---|---|
| **Name** | **Description** |
| `key` | `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Entity>` |   |

### get(Iterable\<Key\> keys)

    public abstract Future<Map<Key,Entity>> get(Iterable<Key> keys)

See [DatastoreService#get(Iterable)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_get_java_lang_Iterable_com_google_appengine_api_datastore_Key__).

| **Parameter** ||
|---|---|
| **Name** | **Description** |
| `keys` | `https://docs.oracle.com/javase/8/docs/api/java/lang/Iterable.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key>` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.oracle.com/javase/8/docs/api/java/util/Map.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key,https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Entity>>` |   |

### getDatastoreAttributes()

    public abstract Future<DatastoreAttributes> getDatastoreAttributes()

See [DatastoreService#getDatastoreAttributes()](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_getDatastoreAttributes__).

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreAttributes>` |   |

### getIndexes()

    public abstract Future<Map<Index,Index.IndexState>> getIndexes()

See [DatastoreService#getIndexes()](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_getIndexes__).

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.oracle.com/javase/8/docs/api/java/util/Map.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Index,https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Index.IndexState>>` |   |

### put(@Nullable Transaction txn, Entity entity)

    public abstract Future<Key> put(@Nullable Transaction txn, Entity entity)

See [DatastoreService#put(Transaction, Entity)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_put_com_google_appengine_api_datastore_Transaction_com_google_appengine_api_datastore_Entity_).

| **Parameters** ||
|---|---|
| **Name** | **Description** |
| `txn` | `com.google.appengine.api.datastore.@org.jspecify.annotations.Nullable Transaction` |
| `entity` | `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Entity` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key>` |   |

### put(@Nullable Transaction txn, Iterable\<Entity\> entities)

    public abstract Future<List<Key>> put(@Nullable Transaction txn, Iterable<Entity> entities)

See [DatastoreService#put(Transaction, Iterable)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_put_com_google_appengine_api_datastore_Transaction_java_lang_Iterable_com_google_appengine_api_datastore_Entity__).

| **Parameters** ||
|---|---|
| **Name** | **Description** |
| `txn` | `com.google.appengine.api.datastore.@org.jspecify.annotations.Nullable Transaction` |
| `entities` | `https://docs.oracle.com/javase/8/docs/api/java/lang/Iterable.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Entity>` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.oracle.com/javase/8/docs/api/java/util/List.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key>>` |   |

### put(Entity entity)

    public abstract Future<Key> put(Entity entity)

See [DatastoreService#put(Entity)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_put_com_google_appengine_api_datastore_Entity_).

| **Parameter** ||
|---|---|
| **Name** | **Description** |
| `entity` | `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Entity` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key>` |   |

### put(Iterable\<Entity\> entities)

    public abstract Future<List<Key>> put(Iterable<Entity> entities)

See [DatastoreService#put(Iterable)](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.DatastoreService#com_google_appengine_api_datastore_DatastoreService_put_java_lang_Iterable_com_google_appengine_api_datastore_Entity__).

| **Parameter** ||
|---|---|
| **Name** | **Description** |
| `entities` | `https://docs.oracle.com/javase/8/docs/api/java/lang/Iterable.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Entity>` |

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/Future.html<https://docs.oracle.com/javase/8/docs/api/java/util/List.html<https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.datastore.Key>>` |   |