Package io.helidon.config.spi

Class AbstractSource<T,S>

java.lang.Object

io.helidon.config.spi.AbstractSource<T,S>

Type Parameters:

T - a type of source data

S - a type of data stamp

All Implemented Interfaces:

Changeable<T>, Source<T>, java.lang.AutoCloseable

Direct Known Subclasses:

AbstractConfigSource, AbstractOverrideSource

public abstract class AbstractSource<T,S>
extends java.lang.Object
implements Source<T>

Abstract base implementation for a variety of sources.

The inner AbstractSource.Builder class is ready-to-extend with built-in support of changes (polling strategy, executor, buffer size) and mandatory/optional attribute.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AbstractSource.Builder<B extends AbstractSource.Builder<B,T,S>,T,S> A common AbstractSource builder, suitable for concrete Builder implementations related to AbstractSource extensions to extend.
static class	AbstractSource.Data<D,S> Data loaded at appropriate time.

Method Summary

Modifier and Type	Method and Description
protected abstract java.util.Optional<S>	dataStamp() Returns current stamp of data in config source.
java.lang.String	description() Short, human-readable summary referring to the underlying source.
protected void	fireChangeEvent() Fires a change event when source has changed.
protected boolean	isMandatory()
java.util.Optional<T>	load() Loads data from source when data expires.
protected abstract AbstractSource.Data<T,S>	loadData() Loads new data from config source.
protected AbstractSource.Data<T,S>	processLoadedData(AbstractSource.Data<T,S> data) Performs any postprocessing of config data after loading.
protected java.lang.String	uid() Returns universal id of source to be used to construct description().

Methods inherited from class java.lang.Object

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

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

changes, close

Method Detail

uid

protected java.lang.String uid()

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

Returns:

universal id of source

isMandatory

protected boolean isMandatory()

fireChangeEvent

protected void fireChangeEvent()

Fires a change event when source has changed.

processLoadedData

protected AbstractSource.Data<T,S> processLoadedData(AbstractSource.Data<T,S> data)

Performs any postprocessing of config data after loading. By default, the method simply returns the provided input Data.

Parameters:

data - an input data

Returns:

a post-processed data

dataStamp

protected abstract java.util.Optional<S> dataStamp()

Returns current stamp of data in config source.

Returns:

current datastamp of data in config source

load

public final java.util.Optional<T> load()

Loads data from source when data expires.

Specified by:

load in interface Source<T>

Returns:

the last loaded data

loadData

protected abstract AbstractSource.Data<T,S> loadData()
                                              throws ConfigException

Loads new data from config source.

Returns:

newly loaded data with appropriate data timestamp used for future method calls

Throws:

ConfigException - in case it is not possible to load configuration data

description

public final java.lang.String description()

Description copied from interface: Source

Short, human-readable summary referring to the underlying source.

For example, a file path or a URL or any other information that helps the user recognize the underlying origin of the data this Source provides.

Default is the implementation class simple name with any "Source" suffix removed.

Specified by:

description in interface Source<T>

Returns:

description of the source