Package org.apache.flink.api.common.state.v2

Class MapStateDescriptor<UK,UV>

java.lang.Object

org.apache.flink.api.common.state.v2.StateDescriptor<UV>

org.apache.flink.api.common.state.v2.MapStateDescriptor<UK,UV>

Type Parameters:

UK - The type of the user key for this map state.

UV - The type of the values that the map state can hold.

All Implemented Interfaces:

Serializable

@Experimental
public class MapStateDescriptor<UK,UV>
extends StateDescriptor<UV>

StateDescriptor for MapState. This can be used to create partitioned map state internally.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.flink.api.common.state.v2.StateDescriptor

StateDescriptor.Type

Constructor Summary

Constructors

Constructor	Description
MapStateDescriptor(String name, Class<UK> keyClass, Class<UV> valueClass)	Create a new MapStateDescriptor with the given name and the given type information.
MapStateDescriptor(String stateId, TypeInformation<UK> userKeyTypeInfo, TypeInformation<UV> userValueTypeInfo)	Creates a new MapStateDescriptor with the given stateId and type.
MapStateDescriptor(String stateId, TypeSerializer<UK> userKeySerializer, TypeSerializer<UV> userValueSerializer)	Create a new MapStateDescriptor with the given stateId and the given type serializer.

Method Summary

Modifier and Type	Method	Description
StateDescriptor.Type	getType()	Return the specific Type of described state.
TypeSerializer<UK>	getUserKeySerializer()
TypeInformation<UK>	getUserKeyTypeInformation()
void	initializeSerializerUnlessSet(ExecutionConfig executionConfig)	Initializes the serializer, unless it has been initialized before.
void	initializeSerializerUnlessSet(SerializerFactory serializerFactory)
boolean	isSerializerInitialized()	Checks whether the serializer has been initialized.

Methods inherited from class org.apache.flink.api.common.state.v2.StateDescriptor

enableTimeToLive, equals, getSerializer, getStateId, getTtlConfig, getTypeInformation, hashCode, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

MapStateDescriptor

public MapStateDescriptor(@Nonnull
                          String stateId,
                          @Nonnull
                          TypeInformation<UK> userKeyTypeInfo,
                          @Nonnull
                          TypeInformation<UV> userValueTypeInfo)

Creates a new MapStateDescriptor with the given stateId and type.

Parameters:

stateId - The (unique) stateId for the state.

userKeyTypeInfo - The type of the user keys in the state.

userValueTypeInfo - The type of the values in the state.

MapStateDescriptor

public MapStateDescriptor(@Nonnull
                          String stateId,
                          @Nonnull
                          TypeSerializer<UK> userKeySerializer,
                          @Nonnull
                          TypeSerializer<UV> userValueSerializer)

Create a new MapStateDescriptor with the given stateId and the given type serializer.

Parameters:

stateId - The (unique) stateId for the state.

userKeySerializer - The serializer for the user keys in the state.

userValueSerializer - The serializer for the user values in the state.

MapStateDescriptor

public MapStateDescriptor(String name,
                          Class<UK> keyClass,
                          Class<UV> valueClass)

Create a new MapStateDescriptor with the given name and the given type information.

If this constructor fails (because it is not possible to describe the type via a class), consider using the MapStateDescriptor(String, TypeInformation, TypeInformation) constructor.

Parameters:

name - The name of the MapStateDescriptor.

keyClass - The class of the type of keys in the state.

valueClass - The class of the type of values in the state.

Method Detail

getUserKeySerializer

@Nonnull
public TypeSerializer<UK> getUserKeySerializer()

getUserKeyTypeInformation

@Internal
@Nullable
public TypeInformation<UK> getUserKeyTypeInformation()

isSerializerInitialized

public boolean isSerializerInitialized()

Checks whether the serializer has been initialized. Serializer initialization is lazy, to allow parametrization of serializers with an ExecutionConfig via initializeSerializerUnlessSet(ExecutionConfig).

Overrides:

isSerializerInitialized in class StateDescriptor<UV>

Returns:

True if the serializers have been initialized, false otherwise.

initializeSerializerUnlessSet

public void initializeSerializerUnlessSet(ExecutionConfig executionConfig)

Initializes the serializer, unless it has been initialized before.

Overrides:

initializeSerializerUnlessSet in class StateDescriptor<UV>

Parameters:

executionConfig - The execution config to use when creating the serializer.

initializeSerializerUnlessSet

public void initializeSerializerUnlessSet(SerializerFactory serializerFactory)

Overrides:

initializeSerializerUnlessSet in class StateDescriptor<UV>

getType

public StateDescriptor.Type getType()

Description copied from class: StateDescriptor

Return the specific Type of described state.

Specified by:

getType in class StateDescriptor<UV>