org.jboss.shrinkwrap.resolver.spi.loader

Class ServiceRegistry

java.lang.Object

org.jboss.shrinkwrap.resolver.spi.loader.ServiceRegistry

All Implemented Interfaces:

ServiceLoader

public class ServiceRegistry
extends Object
implements ServiceLoader

A simple singleton (application scoped} registry that fulfills ServiceLoader contract. This registry uses underlying ServiceLoader implementation to load the service while storing cached instances in a local map.

Author:

Karel Piwko

Constructor Summary

Constructors

Constructor and Description
ServiceRegistry(ServiceLoader serviceLoader) Creates a service registry with a ServiceLoader to load service instances until they are cached

Method Summary

Methods

Modifier and Type	Method and Description
<T> Collection<T>	all(Class<T> serviceClass) Loads all registered services for given serviceClass
static ServiceRegistry	getInstance() Returns ServiceRegistry instance.
<T> T	onlyOne(Class<T> serviceClass) Loads a registered service for given serviceClass
<T> T	onlyOne(Class<T> serviceClass, Class<? extends T> defaultImplementationClass) Loads a registered service for given serviceClass.
static void	register(ServiceRegistry registry) Registers an instance of ServiceRegistry.

Methods inherited from class java.lang.Object

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

Constructor Detail

ServiceRegistry

public ServiceRegistry(ServiceLoader serviceLoader)

Creates a service registry with a ServiceLoader to load service instances until they are cached

Parameters:

serviceLoader -

Method Detail

getInstance

public static ServiceRegistry getInstance()
                                   throws IllegalStateException

Returns ServiceRegistry instance. Instance must be registered first.

Returns:

Throws:

IllegalStateException - If no service registry was registered yet

register

public static void register(ServiceRegistry registry)

Registers an instance of ServiceRegistry.

Parameters:

registry -

all

public <T> Collection<T> all(Class<T> serviceClass)
                  throws IllegalArgumentException

Loads all registered services for given serviceClass

Specified by:

all in interface ServiceLoader

Parameters:

serviceClass -

Returns:

Throws:

IllegalArgumentException - If serviceClass is null

onlyOne

public <T> T onlyOne(Class<T> serviceClass)
          throws IllegalArgumentException,
                 IllegalStateException

Loads a registered service for given serviceClass

Specified by:

onlyOne in interface ServiceLoader

Parameters:

serviceClass -

Returns:

Throws:

IllegalArgumentException - If either classLoader or serviceClass is null

IllegalStateException - If more than a single service is registered

onlyOne

public <T> T onlyOne(Class<T> serviceClass,
            Class<? extends T> defaultImplementationClass)
          throws IllegalArgumentException,
                 IllegalStateException

Loads a registered service for given serviceClass. Reverts to the defaultImplementationClass if no other service is registered. If defaultImplemenationClass is registered as well, it simply ignores it during resolution.

Specified by:

onlyOne in interface ServiceLoader

Parameters:

serviceClass -

defaultImplementationClass -

Returns:

Throws:

IllegalArgumentException - If either serviceClass or defaultImplementationClass is null

IllegalStateException - If more than a single service is registered