Class SoftServiceLoader<S>

java.lang.Object

io.micronaut.core.io.service.SoftServiceLoader<S>

Type Parameters:

S - The service type

All Implemented Interfaces:

Iterable<ServiceDefinition<S>>

public final class SoftServiceLoader<S>
extends Object
implements Iterable<ServiceDefinition<S>>

Variation of ServiceLoader that allows soft loading and conditional loading of META-INF/services classes.

Since:

1.0

Author:

Graeme Rocher

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	SoftServiceLoader.Optimizations	Static optimizations for service loaders.
static interface	SoftServiceLoader.ServiceCollector<S>	Service collector for loading services of the given type.
static final class	SoftServiceLoader.StaticDefinition<S>	A ServiceDefinition implementation that creates instances using the same instantiation strategy as instantiate(Class): it first attempts to invoke a no-argument constructor via a MethodHandles.Lookup method handle, and if that fails due to access restrictions or similar conditions, it falls back to reflective instantiation using invalid reference java.lang.Class#getDeclaredConstructor() .
static interface	SoftServiceLoader.StaticServiceLoader<S>	Service loader that uses SoftServiceLoader.StaticDefinition.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	META_INF_SERVICES

Method Summary

Modifier and Type	Method	Description
List<S>	collectAll()	Collects all initialized instances.
void	collectAll(Collection<S> values)	Collects all initialized instances.
void	collectAll(Collection<S> values, @Nullable Predicate<S> predicate)	Collects all initialized instances.
List<S>	collectAll(@Nullable Predicate<S> predicate)	Collects all initialized instances.
SoftServiceLoader<S>	disableFork()
Optional<ServiceDefinition<S>>	first()
Optional<S>	firstAvailable()	Find the first service definition that is present, and then load it.
Optional<ServiceDefinition<S>>	firstOr(String alternative, ClassLoader classLoader)
Iterator<ServiceDefinition<S>>	iterator()
static <S> SoftServiceLoader<S>	load(Class<S> service)	Creates a new SoftServiceLoader using the thread context loader by default.
static <S> SoftServiceLoader<S>	load(Class<S> service, @Nullable ClassLoader loader)	Creates a new SoftServiceLoader using the given type and class loader.
static <S> SoftServiceLoader<S>	load(Class<S> service, @Nullable ClassLoader loader, @Nullable Predicate<String> condition)	Creates a new SoftServiceLoader using the given type and class loader.
static <S> SoftServiceLoader.ServiceCollector<S>	newCollector(String serviceName, Predicate<String> lineCondition, ClassLoader classLoader, Function<String,S> transformer)

Methods inherited from class Object

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

Methods inherited from interface Iterable

forEach, spliterator

Field Details

META_INF_SERVICES

public static final String META_INF_SERVICES

See Also:

• Constant Field Values

Method Details

load

public static <S> SoftServiceLoader<S> load(Class<S> service)

Creates a new SoftServiceLoader using the thread context loader by default.

Type Parameters:

S - The service generic type

Parameters:

service - The service type

Returns:

A new service loader

load

public static <S> SoftServiceLoader<S> load(Class<S> service,
 @Nullable ClassLoader loader)

Creates a new SoftServiceLoader using the given type and class loader.

Type Parameters:

S - The service generic type

Parameters:

service - The service type

loader - The class loader

Returns:

A new service loader

load

public static <S> SoftServiceLoader<S> load(Class<S> service,
 @Nullable ClassLoader loader,
 @Nullable Predicate<String> condition)

Creates a new SoftServiceLoader using the given type and class loader.

Type Parameters:

S - The service generic type

Parameters:

service - The service type

loader - The class loader to use

condition - A Predicate to use to conditionally load the service. The predicate is passed the service class name

Returns:

A new service loader

disableFork

public SoftServiceLoader<S> disableFork()

first

public Optional<ServiceDefinition<S>> first()

Returns:

Return the first such instance

firstAvailable

public Optional<S> firstAvailable()

Find the first service definition that is present, and then load it.

Returns:

Return the first such instance, or Optional.empty() if there is no definition or none of the definitions are present on the classpath.

firstOr

public Optional<ServiceDefinition<S>> firstOr(String alternative,
 ClassLoader classLoader)

Parameters:

alternative - An alternative type to use if this type is not present

classLoader - The classloader

Returns:

Return the first such instance

collectAll

public void collectAll(Collection<S> values,
 @Nullable Predicate<S> predicate)

Collects all initialized instances.

Parameters:

values - The collection to be populated.

predicate - The predicated to filter the instances or null if not needed.

collectAll

public void collectAll(Collection<S> values)

Collects all initialized instances.

Parameters:

values - The collection to be populated.

collectAll

public List<S> collectAll()

Collects all initialized instances.

Returns:

The instances of this service.

collectAll

public List<S> collectAll(@Nullable Predicate<S> predicate)

Collects all initialized instances.

Parameters:

predicate - The predicated to filter the instances or null if not needed.

Returns:

The instances of this service.

iterator

public Iterator<ServiceDefinition<S>> iterator()

Specified by:

iterator in interface Iterable<S>

Returns:

The iterator

newCollector

public static <S>
SoftServiceLoader.ServiceCollector<S> newCollector(String serviceName,
 Predicate<String> lineCondition,
 ClassLoader classLoader,
 Function<String,S> transformer)