org.eclipse.rdf4j.common.lang.service

Class ServiceRegistry<K,S>

java.lang.Object

org.eclipse.rdf4j.common.lang.service.ServiceRegistry<K,S>

Direct Known Subclasses:

DatatypeHandlerRegistry, FileFormatServiceRegistry, FunctionRegistry, LanguageHandlerRegistry, QueryParserRegistry, RepositoryRegistry, SailRegistry, TupleFunctionRegistry

public abstract class ServiceRegistry<K,S>
extends Object

A registry that stores services by some key. Upon initialization, the registry searches for service description files at META-INF/services/<service class name> and initializes itself accordingly.

Author:

Arjohn Kampman

See Also:

ServiceRegistry

Field Summary

Fields

Modifier and Type	Field and Description
protected org.slf4j.Logger	logger
protected Map<K,S>	services

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ServiceRegistry(Class<S> serviceClass)

Method Summary

Modifier and Type	Method and Description
Optional<S>	add(S service) Adds a service to the registry.
Optional<S>	get(K key) Gets the service for the specified key, if any.
Collection<S>	getAll() Gets all registered services.
protected abstract K	getKey(S service) Gets the key for the specified service.
Set<K>	getKeys() Gets the set of registered keys.
boolean	has(K key) Checks whether a service for the specified key is available.
void	remove(S service) Removes a service from the registry.

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected final org.slf4j.Logger logger

services

protected Map<K,S> services

Constructor Detail

ServiceRegistry

protected ServiceRegistry(Class<S> serviceClass)

Method Detail

add

public Optional<S> add(S service)

Adds a service to the registry. Any service that is currently registered for the same key (as specified by getKey(Object)) will be replaced with the new service.

Parameters:

service - The service that should be added to the registry.

Returns:

The previous service that was registered for the same key, or Optional.empty() if there was no such service.

remove

public void remove(S service)

Removes a service from the registry.

Parameters:

service - The service be removed from the registry.

get

public Optional<S> get(K key)

Gets the service for the specified key, if any.

Parameters:

key - The key identifying which service to get.

Returns:

The service for the specified key, or Optional.empty() if no such service is avaiable.

has

public boolean has(K key)

Checks whether a service for the specified key is available.

Parameters:

key - The key identifying which service to search for.

Returns:

true if a service for the specific key is available, false otherwise.

getAll

public Collection<S> getAll()

Gets all registered services.

Returns:

An unmodifiable collection containing all registered servivces.

getKeys

public Set<K> getKeys()

Gets the set of registered keys.

Returns:

An unmodifiable set containing all registered keys.

getKey

protected abstract K getKey(S service)

Gets the key for the specified service.

Parameters:

service - The service to get the key for.

Returns:

The key for the specified service.