ej.service.loader

Class SimpleServiceLoader

java.lang.Object

ej.service.loader.SimpleServiceLoader

All Implemented Interfaces:

ServiceLoader

Direct Known Subclasses:

CompositeServiceLoader, DependencyInjectionServiceLoader, SimpleServiceRegistry

public abstract class SimpleServiceLoader
extends Object
implements ServiceLoader

Service loader that creates service instance based on default service implementation class.

Constructor Summary

Constructors

Constructor and Description
SimpleServiceLoader() Instantiates a new default service loader.

Method Summary

Modifier and Type	Method and Description
protected <T> void	checkServicePermission(Class<T> service, String action) Checks that an action on a service is permitted.
protected <T> T	createAlternativeImplementation(Class<T> service) Creates an implementation for the given service and save it in the cache.
<T> T	getService(Class<T> service) Gets the instance of the given service.
protected <T> void	putService(Class<T> service, T instance) Put a service in the services map in a synchronized context.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleServiceLoader

public SimpleServiceLoader()

Instantiates a new default service loader.

Method Detail

getService

@Nullable
public <T> T getService(Class<T> service)

Description copied from interface: ServiceLoader

Gets the instance of the given service.

If there is already an instance in cache, it is returned otherwise a new one is created.

May return null if the service is not defined.

Specified by:

getService in interface ServiceLoader

Type Parameters:

T - the service type.

Parameters:

service - the service.

Returns:

the instance of the given service.

checkServicePermission

protected <T> void checkServicePermission(Class<T> service,
                                          String action)

Checks that an action on a service is permitted.

Type Parameters:

T - the service type.

Parameters:

service - the service.

action - the action.

createAlternativeImplementation

@Nullable
protected <T> T createAlternativeImplementation(Class<T> service)
                                                    throws ServiceLoadingException

Creates an implementation for the given service and save it in the cache.

Type Parameters:

T - the service type.

Parameters:

service - the service.

Returns:

a new instance of the given service or null.

Throws:

ServiceLoadingException - if an error occurs while instantiating the service instance.

putService

protected <T> void putService(Class<T> service,
                              T instance)

Put a service in the services map in a synchronized context.

Type Parameters:

T - the service type.

Parameters:

service - the service.

instance - the service instance.