org.apache.nifi.components.state

Interface StateMap

public interface StateMap

Provides a representation of a component's state at some point in time.

Method Summary

Modifier and Type	Method and Description
String	get(String key) Returns the value associated with the given key
default Optional<String>	getStateVersion() Get state version is not guaranteed to be numeric, but can be used to compare against an expected version.
long	getVersion() Deprecated.
Map<String,String>	toMap() Returns an immutable Map representation of all keys and values for the state of a component.

Method Detail

getVersion

@Deprecated
long getVersion()

Deprecated.

Each time that a component's state is updated, the state is assigned a new version. This version can then be used to atomically update state by the backing storage mechanism. Though this number is monotonically increasing, it should not be expected to increment always from X to X+1. I.e., version numbers may be skipped.

Returns:

the version associated with the state

getStateVersion

default Optional<String> getStateVersion()

Get state version is not guaranteed to be numeric, but can be used to compare against an expected version. The default implementation uses the available version number and considers -1 as indicating an empty version

Returns:

State version or empty when not known

get

String get(String key)

Returns the value associated with the given key

Parameters:

key - the key whose value should be retrieved

Returns:

the value associated with the given key, or null if no value is associated with this key.

toMap

Map<String,String> toMap()

Returns an immutable Map representation of all keys and values for the state of a component.

Returns:

an immutable Map representation of all keys and values for the state of a component.