org.apache.flink.api.common.state

Class ValueStateDescriptor<T>

java.lang.Object

org.apache.flink.api.common.state.StateDescriptor<ValueState<T>,T>

org.apache.flink.api.common.state.ValueStateDescriptor<T>

Type Parameters:

T - The type of the values that the value state can hold.

All Implemented Interfaces:

Serializable

@PublicEvolving
public class ValueStateDescriptor<T>
extends StateDescriptor<ValueState<T>,T>

StateDescriptor for ValueState. This can be used to create partitioned value state using RuntimeContext.getState(ValueStateDescriptor).

If you don't use one of the constructors that set a default value the value that you get when reading a ValueState using ValueState.value() will be null.

See Also:

Serialized Form

Nested Class Summary

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

StateDescriptor.Type

Field Summary

Fields inherited from class org.apache.flink.api.common.state.StateDescriptor

defaultValue, name, serializer

Constructor Summary

Constructors

Constructor and Description
ValueStateDescriptor(String name, Class<T> typeClass) Creates a new ValueStateDescriptor with the given name and type
ValueStateDescriptor(String name, Class<T> typeClass, T defaultValue) Deprecated. Use ValueStateDescriptor(String, Class) instead and manually manage the default value by checking whether the contents of the state is null.
ValueStateDescriptor(String name, TypeInformation<T> typeInfo) Creates a new ValueStateDescriptor with the given name and type.
ValueStateDescriptor(String name, TypeInformation<T> typeInfo, T defaultValue) Deprecated. Use ValueStateDescriptor(String, TypeInformation) instead and manually manage the default value by checking whether the contents of the state is null.
ValueStateDescriptor(String name, TypeSerializer<T> typeSerializer) Creates a new ValueStateDescriptor with the given name and the specific serializer.
ValueStateDescriptor(String name, TypeSerializer<T> typeSerializer, T defaultValue) Deprecated. Use ValueStateDescriptor(String, TypeSerializer) instead and manually manage the default value by checking whether the contents of the state is null.

Method Summary

Methods

Modifier and Type	Method and Description
ValueState<T>	bind(StateBinder stateBinder) Creates a new State on the given StateBinder.
boolean	equals(Object o)
StateDescriptor.Type	getType()
int	hashCode()
String	toString()

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

getDefaultValue, getName, getQueryableStateName, getSerializer, initializeSerializerUnlessSet, isQueryable, isSerializerInitialized, setQueryable

Methods inherited from class java.lang.Object

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

Constructor Detail

ValueStateDescriptor

@Deprecated
public ValueStateDescriptor(String name,
                               Class<T> typeClass,
                               T defaultValue)

Deprecated. Use ValueStateDescriptor(String, Class) instead and manually manage the default value by checking whether the contents of the state is null.

Creates a new ValueStateDescriptor with the given name, type, and default value.

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

Parameters:

name - The (unique) name for the state.

typeClass - The type of the values in the state.

defaultValue - The default value that will be set when requesting state without setting a value before.

ValueStateDescriptor

@Deprecated
public ValueStateDescriptor(String name,
                               TypeInformation<T> typeInfo,
                               T defaultValue)

Deprecated. Use ValueStateDescriptor(String, TypeInformation) instead and manually manage the default value by checking whether the contents of the state is null.

Creates a new ValueStateDescriptor with the given name and default value.

Parameters:

name - The (unique) name for the state.

typeInfo - The type of the values in the state.

defaultValue - The default value that will be set when requesting state without setting a value before.

ValueStateDescriptor

@Deprecated
public ValueStateDescriptor(String name,
                               TypeSerializer<T> typeSerializer,
                               T defaultValue)

Deprecated. Use ValueStateDescriptor(String, TypeSerializer) instead and manually manage the default value by checking whether the contents of the state is null.

Creates a new ValueStateDescriptor with the given name, default value, and the specific serializer.

Parameters:

name - The (unique) name for the state.

typeSerializer - The type serializer of the values in the state.

defaultValue - The default value that will be set when requesting state without setting a value before.

ValueStateDescriptor

public ValueStateDescriptor(String name,
                    Class<T> typeClass)

Creates a new ValueStateDescriptor with the given name and type

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

Parameters:

name - The (unique) name for the state.

typeClass - The type of the values in the state.

ValueStateDescriptor

public ValueStateDescriptor(String name,
                    TypeInformation<T> typeInfo)

Creates a new ValueStateDescriptor with the given name and type.

Parameters:

name - The (unique) name for the state.

typeInfo - The type of the values in the state.

ValueStateDescriptor

public ValueStateDescriptor(String name,
                    TypeSerializer<T> typeSerializer)

Creates a new ValueStateDescriptor with the given name and the specific serializer.

Parameters:

name - The (unique) name for the state.

typeSerializer - The type serializer of the values in the state.

Method Detail

bind

public ValueState<T> bind(StateBinder stateBinder)
                   throws Exception

Description copied from class: StateDescriptor

Creates a new State on the given StateBinder.

Specified by:

bind in class StateDescriptor<ValueState<T>,T>

Parameters:

stateBinder - The StateBackend on which to create the State.

Throws:

Exception

equals

public boolean equals(Object o)

Specified by:

equals in class StateDescriptor<ValueState<T>,T>

hashCode

public int hashCode()

Specified by:

hashCode in class StateDescriptor<ValueState<T>,T>

toString

public String toString()

Overrides:

toString in class StateDescriptor<ValueState<T>,T>

getType

public StateDescriptor.Type getType()

Specified by:

getType in class StateDescriptor<ValueState<T>,T>