org.apache.flink.api.common.state

接口 ListState<T>

类型参数:

T - Type of values that this list state keeps.

所有超级接口:

AppendingState<T,Iterable<T>>, MergingState<T,Iterable<T>>, State

@PublicEvolving
public interface ListState<T>
extends MergingState<T,Iterable<T>>

State interface for partitioned list state in Operations. The state is accessed and modified by user functions, and checkpointed consistently by the system as part of the distributed snapshots.

The state can be a keyed list state or an operator list state.

When it is a keyed list state, it is accessed by functions applied on a KeyedStream. The key is automatically supplied by the system, so the function always sees the value mapped to the key of the current element. That way, the system can handle stream and state partitioning consistently together.

When it is an operator list state, the list is a collection of state items that are independent from each other and eligible for redistribution across operator instances in case of changed operator parallelism.

方法概要

限定符和类型	方法和说明
void	addAll(List<T> values) Updates the operator state accessible by AppendingState.get() by adding the given values to existing list of values.
void	update(List<T> values) Updates the operator state accessible by AppendingState.get() by updating existing values to to the given list of values.

从接口继承的方法 org.apache.flink.api.common.state.AppendingState

add, get

从接口继承的方法 org.apache.flink.api.common.state.State

clear

方法详细资料

update

void update(List<T> values)
     throws Exception

Updates the operator state accessible by AppendingState.get() by updating existing values to to the given list of values. The next time AppendingState.get() is called (for the same state partition) the returned state will represent the updated list.

If null or an empty list is passed in, the state value will be null.

参数:

values - The new values for the state.

抛出:

Exception - The method may forward exception thrown internally (by I/O or functions).

addAll

void addAll(List<T> values)
     throws Exception

Updates the operator state accessible by AppendingState.get() by adding the given values to existing list of values. The next time AppendingState.get() is called (for the same state partition) the returned state will represent the updated list.

If null or an empty list is passed in, the state value remains unchanged.

参数:

values - The new values to be added to the state.

抛出:

Exception - The method may forward exception thrown internally (by I/O or functions).