org.springframework.cloud.gcp.data.datastore.core

Interface DatastoreOperations

All Known Implementing Classes:

DatastoreTemplate

public interface DatastoreOperations

An interface of operations that can be done with Cloud Datastore.

Since:

1.1

Author:

Chengyuan Zhao, Vinicius Carvalho

Method Summary

Modifier and Type	Method and Description
long	count(Class<?> entityClass) Count all occurrences of entities of the given domain type.
Key	createKey(Class aClass, Object id) Create a Key from entity class and id value.
Key	createKey(String kind, Object id) Create a Key from kind name and id.
<T> void	delete(T entity) Delete an entity from Cloud Datastore.
long	deleteAll(Class<?> entityClass) Delete all entities of a given domain type.
<T> void	deleteAll(Iterable<T> entities) Deletes multiple entities from Cloud Datastore.
<T> void	deleteAllById(Iterable<?> ids, Class<T> entityClass) Delete multiple IDs from Cloud Datastore.
<T> void	deleteById(Object id, Class<T> entityClass) Delete an entity from Cloud Datastore.
<T> boolean	existsById(Object id, Class<T> entityClass) Check if the given ID belongs to an entity in Cloud Datastore.
<T> Iterable<T>	findAll(Class<T> entityClass) Get all the entities of the given domain type.
<T> Collection<T>	findAll(Class<T> entityClass, DatastoreQueryOptions queryOptions) Get all the entities of the given domain type applying limit, offset and sort.
<T> Iterable<T>	findAllById(Iterable<?> ids, Class<T> entityClass) Find all the entities of the given IDs.
<T> T	findById(Object id, Class<T> entityClass) Get an entity based on a id.
<T> Map<String,T>	findByIdAsMap(Key key, Class<T> valueType) Get a Datastore entity based on a id and convert it to a map.
DatastoreEntityConverter	getDatastoreEntityConverter() Get the DatastoreEntityConverter used by this template.
Key	getKey(Object entity) Create a Key from id property of an entity object.
<T> Iterable<Key>	keyQueryByExample(org.springframework.data.domain.Example<T> example, DatastoreQueryOptions queryOptions) Run key query by example.
<A> A	performTransaction(Function<DatastoreOperations,A> operations) Performs multiple read and write operations in a single transaction.
<T> Iterable<T>	query(Query<? extends BaseEntity> query, Class<T> entityClass) Finds objects by using a Cloud Datastore query.
<A,T> Iterable<T>	query(Query<A> query, Function<A,T> entityFunc) Runs given query and applies given function to each entity in the result.
<T> Iterable<T>	queryByExample(org.springframework.data.domain.Example<T> example, DatastoreQueryOptions queryOptions) Run query by example.
<T> org.springframework.data.domain.Slice<T>	queryEntitiesSlice(StructuredQuery query, Class<T> entityClass, org.springframework.data.domain.Pageable pageable) Finds entities by using a Cloud Datastore query.
<A,T> DatastoreResultsIterable<T>	queryIterable(Query<A> query, Function<A,T> entityFunc) Runs given query and applies given function to each entity in the result.
Iterable<Key>	queryKeys(Query<Key> query) Finds Cloud Datastore Keys by using a Cloud Datastore query.
<T> DatastoreResultsIterable<?>	queryKeysOrEntities(Query query, Class<T> entityClass) Finds objects by using a Cloud Datastore query.
<T> org.springframework.data.domain.Slice<Key>	queryKeysSlice(KeyQuery query, Class<T> entityClass, org.springframework.data.domain.Pageable pageable) Finds keys by using a Cloud Datastore query.
<T> T	save(T instance, Key... ancestors) Saves an instance of an object to Cloud Datastore.
<T> Iterable<T>	saveAll(Iterable<T> entities, Key... ancestors) Saves multiple instances of objects to Cloud Datastore.
<V> void	writeMap(Key key, Map<String,V> map) Save a map as a Datastore entity, using map keys as field names.

Method Detail

findById

<T> T findById(Object id,
               Class<T> entityClass)

Get an entity based on a id.

Type Parameters:

T - the class type of the entity.

Parameters:

id - the id of the entity. If this is actually a Key then it will be used. Otherwise it will be attempted to be converted to an integer or string value and it will be assumed to be a root key value with the Kind determined by the entityClass. param.

entityClass - the type of the entity to get.

Returns:

the entity that was found with that id.

save

<T> T save(T instance,
           Key... ancestors)

Saves an instance of an object to Cloud Datastore. Behaves as update or insert. Ancestors can be added only to entries with Key ids.

Type Parameters:

T - the type of the object to save

Parameters:

instance - the instance to save.

ancestors - ancestors that should be added to the entry

Returns:

the instance that was saved.

saveAll

<T> Iterable<T> saveAll(Iterable<T> entities,
                        Key... ancestors)

Saves multiple instances of objects to Cloud Datastore. Behaves as update or insert. Ancestors can be added only to entries with Key ids.

Type Parameters:

T - the type of entities to save

Parameters:

entities - the objects to save.

ancestors - ancestors that should be added to each entry

Returns:

the entities that were saved.

deleteById

<T> void deleteById(Object id,
                    Class<T> entityClass)

Delete an entity from Cloud Datastore. Deleting IDs that do not exist in Cloud Datastore will result in no operation.

Type Parameters:

T - ths entity type

Parameters:

id - the ID of the entity to delete. If this is actually a Key then it will be used. Otherwise it will be attempted to be converted to an integer or string value and it will be assumed to be a root key value with the Kind determined by the entityClass.

entityClass - the type of the

deleteAllById

<T> void deleteAllById(Iterable<?> ids,
                       Class<T> entityClass)

Delete multiple IDs from Cloud Datastore. Deleting IDs that do not exist in Cloud Datastore will result in no operation.

Type Parameters:

T - ths entity type

Parameters:

ids - the IDs to delete. If any of these is actually a Key then it will be used. Otherwise it will be attempted to be converted to an integer or string value and it will be assumed to be a root key value with the Kind determined by the entityClass.

entityClass - the type of the

delete

<T> void delete(T entity)

Delete an entity from Cloud Datastore. Deleting entities that don't exist in Cloud Datastore will result in no operation.

Type Parameters:

T - the entity type

Parameters:

entity - the entity to delete.

deleteAll

<T> void deleteAll(Iterable<T> entities)

Deletes multiple entities from Cloud Datastore. Deleting entities that don't exist in Cloud Datastore will result in no operation.

Type Parameters:

T - the entity type.

Parameters:

entities - the entities to delete.

deleteAll

long deleteAll(Class<?> entityClass)

Delete all entities of a given domain type.

Parameters:

entityClass - the domain type to delete from Cloud Datastore.

Returns:

the number of entities that were deleted.

count

long count(Class<?> entityClass)

Count all occurrences of entities of the given domain type.

Parameters:

entityClass - the domain type to count.

Returns:

the number of entities of the given type.

findAllById

<T> Iterable<T> findAllById(Iterable<?> ids,
                            Class<T> entityClass)

Find all the entities of the given IDs. If an ID is actually a Key then it will be used. Otherwise it will be attempted to be converted to an integer or string value and it will be assumed to be a root key value with the Kind determined by the entityClass.

Type Parameters:

T - the type parameter of the domain type.

Parameters:

ids - the IDs to search.

entityClass - the domain type of the objects.

Returns:

the entities that were found.

query

<T> Iterable<T> query(Query<? extends BaseEntity> query,
                      Class<T> entityClass)

Finds objects by using a Cloud Datastore query.

Type Parameters:

T - the type of object to retrieve.

Parameters:

query - the query to execute.

entityClass - the type of object to retrieve.

Returns:

an iterable containing found entities

query

<A,T> Iterable<T> query(Query<A> query,
                        Function<A,T> entityFunc)

Runs given query and applies given function to each entity in the result.

Type Parameters:

A - the row type of the query. This type can be either Key or a Cloud Datastore entity.

T - the type to map each entity or key to.

Parameters:

query - the query to run.

entityFunc - the function to apply to each found entity or key.

Returns:

the mapped entities or keys.

queryKeys

Iterable<Key> queryKeys(Query<Key> query)

Finds Cloud Datastore Keys by using a Cloud Datastore query.

Parameters:

query - the query to execute that retrieves only Keys.

Returns:

the list of keys found.

findAll

<T> Iterable<T> findAll(Class<T> entityClass)

Get all the entities of the given domain type.

Type Parameters:

T - the type param of the domain type.

Parameters:

entityClass - the domain type to get.

Returns:

the entities that were found.

findAll

<T> Collection<T> findAll(Class<T> entityClass,
                          DatastoreQueryOptions queryOptions)

Get all the entities of the given domain type applying limit, offset and sort.

Type Parameters:

T - the type param of the domain type.

Parameters:

entityClass - the domain type to get.

queryOptions - query options

Returns:

the entities that were found.

existsById

<T> boolean existsById(Object id,
                       Class<T> entityClass)

Check if the given ID belongs to an entity in Cloud Datastore. If this is actually a Key then it will be used. Otherwise it will be attempted to be converted to an integer or string value and it will be assumed to be a root key value with the Kind determined by the entityClass.

Type Parameters:

T - the type param of the domain type.

Parameters:

id - the ID to search for.

entityClass - the domain type of the entities to search for.

Returns:

true if the given ID refers to an existing entity. False otherwise.

performTransaction

<A> A performTransaction(Function<DatastoreOperations,A> operations)

Performs multiple read and write operations in a single transaction.

Type Parameters:

A - the final return type of the operations.

Parameters:

operations - the function that uses DatastoreOperations to perform operations in a transaction.

Returns:

the final result of the transaction.

findByIdAsMap

<T> Map<String,T> findByIdAsMap(Key key,
                                Class<T> valueType)

Get a Datastore entity based on a id and convert it to a map.

Type Parameters:

T - the value type of the map

Parameters:

key - the key of the entity

valueType - type values should be converted to

Returns:

if an entity for a given key exists, returns the map representation of it, null otherwise

writeMap

<V> void writeMap(Key key,
                  Map<String,V> map)

Save a map as a Datastore entity, using map keys as field names.

Type Parameters:

V - the value type of the map to write

Parameters:

key - the key for the entity

map - a map

createKey

Key createKey(String kind,
              Object id)

Create a Key from kind name and id.

Parameters:

kind - the Cloud Datastore kind name

id - object to be used as id; if it is a Long, the value is used, otherwise it isconverted to String

Returns:

created key

createKey

Key createKey(Class aClass,
              Object id)

Create a Key from entity class and id value.

Parameters:

aClass - the Cloud Datastore entity class

id - object to be used as id; if it is a Long, the value is used, otherwise it is converted to String

Returns:

created key

getKey

Key getKey(Object entity)

Create a Key from id property of an entity object.

Parameters:

entity - the Cloud Datastore entity object

Returns:

key for the given entity

queryByExample

<T> Iterable<T> queryByExample(org.springframework.data.domain.Example<T> example,
                               DatastoreQueryOptions queryOptions)

Run query by example.

Type Parameters:

T - the type of probe and resulted entities

Parameters:

example - the example

queryOptions - the query options

Returns:

query results, converted to objects of class T

keyQueryByExample

<T> Iterable<Key> keyQueryByExample(org.springframework.data.domain.Example<T> example,
                                    DatastoreQueryOptions queryOptions)

Run key query by example.

Type Parameters:

T - the type of probe

Parameters:

example - the example

queryOptions - the query options

Returns:

result keys

getDatastoreEntityConverter

DatastoreEntityConverter getDatastoreEntityConverter()

Get the DatastoreEntityConverter used by this template.

Returns:

the converter.

queryKeysSlice

<T> org.springframework.data.domain.Slice<Key> queryKeysSlice(KeyQuery query,
                                                              Class<T> entityClass,
                                                              org.springframework.data.domain.Pageable pageable)

Finds keys by using a Cloud Datastore query. Resulting Slice can be used to get a Pageable for the next page or to determine if the next page exists.

Type Parameters:

T - the type of object to retrieve.

Parameters:

query - the query to execute.

entityClass - the type of object to retrieve.

pageable - that indicates page number and page size

Returns:

a Slice containing found objects

queryEntitiesSlice

<T> org.springframework.data.domain.Slice<T> queryEntitiesSlice(StructuredQuery query,
                                                                Class<T> entityClass,
                                                                org.springframework.data.domain.Pageable pageable)

Finds entities by using a Cloud Datastore query. Resulting Slice can be used to get a Pageable for the next page or to determine if the next page exists.

Type Parameters:

T - the type of object to retrieve.

Parameters:

query - the query to execute.

entityClass - the type of object to retrieve.

pageable - that indicates page number and page size

Returns:

a Slice containing found objects

queryKeysOrEntities

<T> DatastoreResultsIterable<?> queryKeysOrEntities(Query query,
                                                    Class<T> entityClass)

Finds objects by using a Cloud Datastore query. If the query is a key-query, then keys are returned.

Type Parameters:

T - the type of object to retrieve.

Parameters:

query - the query to execute.

entityClass - the type of object to retrieve.

Returns:

an iterable containing found objects and a cursor

queryIterable

<A,T> DatastoreResultsIterable<T> queryIterable(Query<A> query,
                                                Function<A,T> entityFunc)

Runs given query and applies given function to each entity in the result.

Type Parameters:

A - the row type of the query. This type can be either Key or a Cloud Datastore entity.

T - the type to map each entity or key to.

Parameters:

query - the query to run.

entityFunc - the function to apply to each found entity or key.

Returns:

the mapped entities or keys.