Module io.helidon.config

Package io.helidon.config

Class DirectoryConfigSource

java.lang.Object

io.helidon.config.AbstractSource

io.helidon.config.AbstractConfigSource

io.helidon.config.DirectoryConfigSource

All Implemented Interfaces:

ConfigSource, NodeConfigSource, PollableSource<Instant>, Source, WatchableSource<Path>, Supplier<ConfigSource>

public class DirectoryConfigSource
extends AbstractConfigSource
implements PollableSource<Instant>, WatchableSource<Path>, NodeConfigSource

ConfigSource implementation that loads configuration content from a directory on a filesystem.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	DirectoryConfigSource.Builder	Common ancestor for config source builders, taking care of configurable options understood by the config module.

Method Summary

Modifier and Type	Method	Description
static DirectoryConfigSource.Builder	builder()	Create a fluent API builder to construct a directory config source.
Optional<ChangeWatcher<Object>>	changeWatcher()	A change watcher of this source, if it implements WatchableSource and has one configured.
static DirectoryConfigSource	create(Config metaConfig)	Initializes config source instance from configuration properties.
boolean	exists()	If the underlying data exist at this time.
boolean	isModified(Instant stamp)	This method is invoked to check if this source has changed.
Optional<ConfigContent.NodeContent>	load()	Loads the underlying source data.
Optional<PollingStrategy>	pollingStrategy()	A polling strategy of this source, if it implements PollableSource and has one configured.
Path	target()	The target of this source.
Class<Path>	targetType()	Target type as supported by this source.
protected String	uid()	Returns universal id of source to be used to construct AbstractSource.description().

Methods inherited from class io.helidon.config.AbstractConfigSource

mediaType, parser, toString

Methods inherited from class io.helidon.config.AbstractSource

description, optional, retryPolicy

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface io.helidon.config.spi.ConfigSource

get, init

Methods inherited from interface io.helidon.config.spi.Source

description, optional, retryPolicy

Method Details

create

public static DirectoryConfigSource create(Config metaConfig)
                                    throws ConfigMappingException,
MissingValueException

Initializes config source instance from configuration properties.

Mandatory properties, see ConfigSources.directory(String):

• path - type Path

Optional properties: see AbstractConfigSourceBuilder.config(Config).

Parameters:

metaConfig - meta-configuration used to initialize returned config source instance from.

Returns:

new instance of config source described by metaConfig

Throws:

MissingValueException - in case the configuration tree does not contain all expected sub-nodes required by the mapper implementation to provide instance of Java type.

ConfigMappingException - in case the mapper fails to map the (existing) configuration tree represented by the supplied configuration node to an instance of a given Java type.

See Also:

• ConfigSources.directory(String)
• AbstractConfigSourceBuilder.config(Config)

builder

public static DirectoryConfigSource.Builder builder()

Create a fluent API builder to construct a directory config source.

Returns:

a new builder instance

uid

protected String uid()

Description copied from class: AbstractSource

Returns universal id of source to be used to construct AbstractSource.description().

Overrides:

uid in class AbstractSource

Returns:

universal id of source

isModified

public boolean isModified(Instant stamp)

Description copied from interface: PollableSource

This method is invoked to check if this source has changed.

Specified by:

isModified in interface PollableSource<Instant>

Parameters:

stamp - the stamp of the last loaded content

Returns:

true if the current data of this config source differ from the loaded data, including cases when the source has disappeared

pollingStrategy

public Optional<PollingStrategy> pollingStrategy()

Description copied from class: AbstractSource

A polling strategy of this source, if it implements PollableSource and has one configured.

Specified by:

pollingStrategy in interface PollableSource<Instant>

Overrides:

pollingStrategy in class AbstractSource

Returns:

polling strategy if any configured

changeWatcher

public Optional<ChangeWatcher<Object>> changeWatcher()

Description copied from class: AbstractSource

A change watcher of this source, if it implements WatchableSource and has one configured.

Specified by:

changeWatcher in interface WatchableSource<Path>

Overrides:

changeWatcher in class AbstractSource

Returns:

change watcher if any configured

target

public Path target()

Description copied from interface: WatchableSource

The target of this source.

Specified by:

target in interface WatchableSource<Path>

Returns:

target this source is configured with, never null

exists

public boolean exists()

Description copied from interface: Source

If the underlying data exist at this time. This is to prevent us loading such a source if we know it does not exist.

Specified by:

exists in interface Source

Returns:

true if the source exists, false otherwise

targetType

public Class<Path> targetType()

Description copied from interface: WatchableSource

Target type as supported by this source.

Specified by:

targetType in interface WatchableSource<Path>

Returns:

class of the target, by default used for WatchableSource.target()

load

public Optional<ConfigContent.NodeContent> load()
                                         throws ConfigException

Description copied from interface: NodeConfigSource

Loads the underlying source data. This method is only called when the source Source.exists().

The method can be invoked repeatedly, for example during retries.

Specified by:

load in interface NodeConfigSource

Returns:

An instance of T as read from the underlying origin of the data (if it exists)

Throws:

ConfigException - in case of errors loading from the underlying origin