de.unkrig.commons.util

Class EnhancedServiceLoader

java.lang.Object

de.unkrig.commons.util.EnhancedServiceLoader

public final class EnhancedServiceLoader
extends Object

An enhanced version of the ServiceLoader class.

While the strategy for searching impementations is identical, the following enhancments exist:

• The load(Class) method caches the instances for each service. (Use reload(Class) to get uncached services.)
• Service instances are not necessarily created by Class.newInstance() (unflexible), but, alternatively, by configuring a (static) class field or a (static, zero-parameter) method that provide the service instance.
• Instead of the (idiotic?) concept of ServiceLoader implementing the Iterable<S>, load(Class) returns an Iterable<S>.
• DEFAULT is a singelton that loads services through the system class loader.

Field Summary

Fields

Modifier and Type	Field and Description
static EnhancedServiceLoader	DEFAULT An instance that loads services through the system class loader.

Constructor Summary

Constructors

Constructor and Description
EnhancedServiceLoader(ClassLoader loader) Initializes an instance that will load services through a given class loader.

Method Summary

Modifier and Type	Method and Description
<S> Iterable<S>	load(Class<S> service)
<S> Iterable<S>	reload(Class<S> service)

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT

public static final EnhancedServiceLoader DEFAULT

An instance that loads services through the system class loader.

Constructor Detail

EnhancedServiceLoader

public EnhancedServiceLoader(ClassLoader loader)

Initializes an instance that will load services through a given class loader.

Method Detail

load

public <S> Iterable<S> load(Class<S> service)
                     throws ServiceConfigurationError

Returns:

All available implementations of the service, cached

Throws:

ServiceConfigurationError

reload

public <S> Iterable<S> reload(Class<S> service)
                       throws ServiceConfigurationError

Returns:

All available implementations of the service, not cached

Throws:

ServiceConfigurationError - Some of the services are badly configured