Module io.inverno.mod.configuration

Package io.inverno.mod.configuration.source

Class CompositeConfigurationSource

java.lang.Object

io.inverno.mod.configuration.source.CompositeConfigurationSource

All Implemented Interfaces:

ConfigurationSource<CompositeConfigurationSource.CompositeConfigurationQuery,CompositeConfigurationSource.CompositeExecutableConfigurationQuery,CompositeConfigurationSource.CompositeListConfigurationQuery>

Direct Known Subclasses:

BootstrapConfigurationSource

public class CompositeConfigurationSource
extends Object
implements ConfigurationSource<CompositeConfigurationSource.CompositeConfigurationQuery,CompositeConfigurationSource.CompositeExecutableConfigurationQuery,CompositeConfigurationSource.CompositeListConfigurationQuery>

A composite configuration source that uses multiple configuration sources to resolve configuration properties.

A composite configuration source uses a CompositeConfigurationStrategy to determine the best matching value among the different sources for a given query.

A composite configuration source queries its sources in sequence. It first applies a new CompositeConfigurationStrategy.CompositeDefaultingStrategy provided by CompositeConfigurationStrategy.createDefaultingStrategy() to the sources that implement DefaultableConfigurationSource. This allows to specify a defaulting strategy when executing queries on each sources. The composite defaulting strategy allows to reduce the queries to execute on each source by keeping track of intermediate results in each round.

Configuration sources are ordered from the highest to lowest priority, the strategy allows to specify whether a result returned by a source for a given query supersedes the result returned in a previous round for the same query (see CompositeConfigurationStrategy.isSuperseded(io.inverno.mod.configuration.ConfigurationKey, io.inverno.mod.configuration.ConfigurationKey, io.inverno.mod.configuration.ConfigurationKey)).

At the end of each round, the strategy is used to determine whether a result resolves a query (see CompositeConfigurationStrategy.isResolved(io.inverno.mod.configuration.ConfigurationKey, io.inverno.mod.configuration.ConfigurationKey)), in which case the query is removed from the list of queries to execute on subsequent sources.

Since:

1.0

Author:

Jeremy Kuhn

See Also:

• ConfigurationSource
• CompositeConfigurationStrategy

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CompositeConfigurationSource.CompositeConfigurationQuery	The configuration query used by the composite configuration source.
static class	CompositeConfigurationSource.CompositeConfigurationQueryResult	The configuration query result returned by a composite configuration source.
static class	CompositeConfigurationSource.CompositeExecutableConfigurationQuery	The executable configuration query used by the composite configuration source.
static class	CompositeConfigurationSource.CompositeListConfigurationQuery	The list configuration query used by the composite configuration source.

Constructor Summary

Constructors

Constructor	Description
CompositeConfigurationSource(List<ConfigurationSource<?,?,?>> sources)	Creates a new composite configuration source with the specified sources ordered from the highest to lowest priority using the default CompositeConfigurationStrategy.lookup() strategy.
CompositeConfigurationSource(List<ConfigurationSource<?,?,?>> sources, CompositeConfigurationStrategy strategy)	Creates a new composite configuration source with the specified sources ordered from the highest to lowest priority and using the specified strategy.

Method Summary

Modifier and Type	Method	Description
CompositeConfigurationSource.CompositeExecutableConfigurationQuery	get(String... names)	Creates a configuration query to retrieve the specified properties.
List<ConfigurationSource<?,?,?>>	getSources()	Returns the list of configuration sources from the highest priority to the lowest.
CompositeConfigurationStrategy	getStrategy()	Returns the composite configuration strategy.
CompositeConfigurationSource.CompositeListConfigurationQuery	list(String name)	Creates a list configuration query to list configuration properties defined with the specified property name.
void	setStrategy(CompositeConfigurationStrategy strategy)	Sets the composite configuration strategy.

Methods inherited from class java.lang.Object

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

Constructor Details

CompositeConfigurationSource

public CompositeConfigurationSource(List<ConfigurationSource<?,?,?>> sources)

Creates a new composite configuration source with the specified sources ordered from the highest to lowest priority using the default CompositeConfigurationStrategy.lookup() strategy.

Parameters:

sources - a list of configuration sources

CompositeConfigurationSource

public CompositeConfigurationSource(List<ConfigurationSource<?,?,?>> sources,
 CompositeConfigurationStrategy strategy)

Creates a new composite configuration source with the specified sources ordered from the highest to lowest priority and using the specified strategy.

Parameters:

sources - a list of configuration sources

strategy - a composite configuration strategy

Method Details

getSources

public List<ConfigurationSource<?,?,?>> getSources()

Returns the list of configuration sources from the highest priority to the lowest.

Returns:

a list of configuration sources

getStrategy

public CompositeConfigurationStrategy getStrategy()

Returns the composite configuration strategy.

Returns:

the composite configuration strategy

setStrategy

public void setStrategy(CompositeConfigurationStrategy strategy)
                 throws NullPointerException

Sets the composite configuration strategy.

Parameters:

strategy - a strategy

Throws:

NullPointerException - if the strategy is null

get

public CompositeConfigurationSource.CompositeExecutableConfigurationQuery get(String... names)
                                                                       throws IllegalArgumentException

Description copied from interface: ConfigurationSource

Creates a configuration query to retrieve the specified properties.

Specified by:

get in interface ConfigurationSource<CompositeConfigurationSource.CompositeConfigurationQuery,CompositeConfigurationSource.CompositeExecutableConfigurationQuery,CompositeConfigurationSource.CompositeListConfigurationQuery>

Parameters:

names - an array of property names

Returns:

an executable configuration query

Throws:

IllegalArgumentException - if the array of names is null or empty

list

public CompositeConfigurationSource.CompositeListConfigurationQuery list(String name)
                                                                  throws IllegalArgumentException

Description copied from interface: ConfigurationSource

Creates a list configuration query to list configuration properties defined with the specified property name.

Specified by:

list in interface ConfigurationSource<CompositeConfigurationSource.CompositeConfigurationQuery,CompositeConfigurationSource.CompositeExecutableConfigurationQuery,CompositeConfigurationSource.CompositeListConfigurationQuery>

Parameters:

name - a property name

Returns:

a list configuration query

Throws:

IllegalArgumentException - if the name is null or empty