Package io.helidon.service.configuration.api

Class ServiceConfigurationProvider

java.lang.Object

io.helidon.service.configuration.api.ServiceConfigurationProvider

Direct Known Subclasses:

HikariCPServiceConfigurationProvider

public abstract class ServiceConfigurationProvider
extends java.lang.Object

An abstract factory of ServiceConfiguration instances.

Author:

Laird Nelson

See Also:

buildFor(Set, Properties), ServiceConfiguration

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ServiceConfigurationProvider(java.lang.String serviceIdentifier) Creates a new ServiceConfigurationProvider.

Method Summary

Modifier and Type	Method and Description
abstract ServiceConfiguration	buildFor(java.util.Set<? extends System> systems, java.util.Properties coordinates) Given a Set of Systems and an optional Properties object representing coordinates identifying a configuration space in which configuration discovery is to take place, returns a new ServiceConfiguration appropriate for the configuration space implied by the supplied parameters, or null if no such ServiceConfiguration is applicable.
protected static System	getAuthoritativeSystem(java.util.Set<? extends System> systems, java.util.Properties coordinates) Given a Set of Systems, returns the System from that Set that is deemed to be the authoritative system, either because it is the only enabled member of the Set or it is the first enabled member of the Set whose System.isAuthoritative() method returns true, or null if there is no authoritative System to be returned.
java.lang.String	getServiceIdentifier() Returns the identifier of the logical service this ServiceConfigurationProvider implementation provides ServiceConfiguration instances for.

Methods inherited from class java.lang.Object

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

Constructor Detail

ServiceConfigurationProvider

protected ServiceConfigurationProvider(java.lang.String serviceIdentifier)

Creates a new ServiceConfigurationProvider.

Parameters:

serviceIdentifier - the identifier of the service this ServiceConfigurationProvider implementation will provide configuration for; must not be null

Throws:

java.lang.NullPointerException - if serviceIdentifier is null

See Also:

getServiceIdentifier()

Method Detail

getServiceIdentifier

public final java.lang.String getServiceIdentifier()

Returns the identifier of the logical service this ServiceConfigurationProvider implementation provides ServiceConfiguration instances for.

This method never returns null.

Repeated invocations of this method will yield identical return values.

Returns:

the identifier of the logical service this ServiceConfigurationProvider implementation provides ServiceConfiguration instances for; never null

See Also:

ServiceConfigurationProvider(String)

buildFor

public abstract ServiceConfiguration buildFor(java.util.Set<? extends System> systems,
                                              java.util.Properties coordinates)

Given a Set of Systems and an optional Properties object representing coordinates identifying a configuration space in which configuration discovery is to take place, returns a new ServiceConfiguration appropriate for the configuration space implied by the supplied parameters, or null if no such ServiceConfiguration is applicable.

Implementations of this method may—and often will—return null.

Multiple invocations of an implementation of this method must result in distinct, though perhaps equal, ServiceConfiguration instances.

Implementations of this method may rely on the fact that all members of the supplied Set of Systems will be enabled.

Implementations of this method must not call the ServiceConfiguration.getInstance(String, Properties) method, as an infinite loop may result.

Parameters:

systems - a Set of Systems found to be in effect; may be null

coordinates - a Properties object containing hints that may help in the implementation of the ServiceConfiguration to be returned; may be null

Returns:

a ServiceConfiguration suitable for the configuration space implied by the supplied parameters, or null if no such ServiceConfiguration is applicable

See Also:

ServiceConfiguration.getInstance(String, Properties)

getAuthoritativeSystem

protected static final System getAuthoritativeSystem(java.util.Set<? extends System> systems,
                                                     java.util.Properties coordinates)

Given a Set of Systems, returns the System from that Set that is deemed to be the authoritative system, either because it is the only enabled member of the Set or it is the first enabled member of the Set whose System.isAuthoritative() method returns true, or null if there is no authoritative System to be returned.

This method may—and often does—return null.

A System is deemed to be the authoritative system if it is enabled and either of the following is true:

• It is the sole member of the supplied Set of Systems.
• It describes itself as being authoritative.

Parameters:

systems - the Systems to inspect; may be null

coordinates - a Properties object containing hints that may help in the implementation of this ServiceConfigurationProvider not currently used but reserved for future use; may be null.

Returns:

a System that is deemed to be authoritative, or null if no such System could be found