Module io.helidon.config

Package io.helidon.config.spi

Interface ChangeWatcher<T>

Type Parameters:

T - target of this change watcher, such as Path

All Known Implementing Classes:

EtcdWatcher, FileSystemWatcher

public interface ChangeWatcher<T>

Similar to a PollingStrategy a change watcher is used to identify a change and trigger reload of a ConfigSource. Where a polling strategy provides polling events to check for changes, change watcher is capable of identifying a change in the underlying target using other means.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	ChangeWatcher.ChangeEvent<T>	A change event, carrying the target, type of change and time of change.

Method Summary

Modifier and Type	Method	Description
void	start(T target, Consumer<ChangeWatcher.ChangeEvent<T>> listener)	Start watching a target for changes.
default void	stop()	Stop watching all targets for changes.
Class<T>	type()	Target supported by this change watcher.

Method Details

start

void start(T target,
 Consumer<ChangeWatcher.ChangeEvent<T>> listener)

Start watching a target for changes. If a change happens, notify the listener.

Parameters:

target - target of this watcher, such as Path

listener - listener that handles reloading of the resource being watched

stop

default void stop()

Stop watching all targets for changes.

type

Class<T> type()

Target supported by this change watcher.

Returns:

type supported