Package org.apache.spark.sql.streaming

Interface ValueState<S>

All Superinterfaces:

Serializable

public interface ValueState<S>
extends Serializable

Interface used for arbitrary stateful operations with the v2 API to capture single value state.

Method Summary

Modifier and Type	Method	Description
void	clear()	Function to remove the state for the current grouping key.
boolean	exists()	Function to check whether state exists for current grouping key or not.
S	get()	Function to get the state value for the current grouping key.
void	update(S newState)	Function to update the value of the state for the current grouping key to the new value.

Method Details

clear

void clear()

Function to remove the state for the current grouping key.

exists

boolean exists()

Function to check whether state exists for current grouping key or not.

Returns:

- true if state exists, false otherwise.

get

S get()

Function to get the state value for the current grouping key. If the state exists, the value is returned. If the state does not exist, the default value for the type is returned for AnyVal types and null for AnyRef types.

Note that it's always recommended to check whether the state exists or not by calling exists() before calling get().

Returns:

- the value of the state if it exists. If the state does not exist, the default value for the type is returned for AnyVal types and null for AnyRef types.

update

void update(S newState)

Function to update the value of the state for the current grouping key to the new value.

Parameters:

newState - - the new value