Module io.helidon.pico.api

Package io.helidon.pico.api

package io.helidon.pico.api

The Pico API provide these annotation types that are typically used at compile time to assign special meaning to the type. It is used in conjunction with Helidon tooling (see the pico-processor and pico-maven-plugin modules) to create and validate the DI module at compile time.

• Contract - signifies that the type can be used for lookup in the service registry.
• ExternalContracts - same as Contract, but applied to the implementation class instead.
• RunLevel - ascribes meaning for when the service should start.

Also note that the set of annotations from both the jakarta.inject and jakarta.annotation modules are the primary way to annotate your DI model types.

Other types from the API are less commonly used, but are still made available for situations where programmatic access is required or desirable in some way. The two most common types for entry into this part of the API are shown below.

• PicoServices - suite of services that are typically delivered by the Pico provider.
• Services - the services registry, which is one such service from this suite.

Class	Description
ActivationLog	Tracks the transformations of ServiceProvider's ActivationStatus in lifecycle activity (i.e., activation startup and deactivation shutdown).
ActivationLogEntry	Log entry for lifecycle related events (i.e., activation startup and deactivation shutdown).
ActivationLogEntry.Interceptor	Ensures that the non-nullable fields are populated with default values.
ActivationLogQuery	Provide a means to query the activation log.
ActivationPhaseReceiver	A receiver of events from the Services registry and providers held by the service registry.
ActivationRequest	Request to activate a service.
ActivationResult	Represents the result of a service activation or deactivation.
ActivationStatus	The activation status.
Activator	Activators are responsible for lifecycle creation and lazy activation of service providers.
Application	An Application instance, if available at runtime, will be expected to provide a blueprint for all service provider's injection points.
Bootstrap	This is the bootstrap needed to provide to Pico initialization.
CallingContext	For internal use only to Helidon.
CallingContextFactory	Factory for creating CallingContext and builders for the calling context.
CommonQualifiers	Commonly used QualifierAndValue types.
ContextualServiceQuery	Combines the ServiceInfo criteria along with the InjectionPointInfo context that the query applies to.
Contract	The Contract annotation is used to relay significance to the type that it annotates.
DeActivationRequest	Request to deactivate a ServiceProvider.
DeActivator	DeActivators are responsible for lifecycle, transitioning a ServiceProvider through its Phase's, notably including any PreDestroy method invocations, and finally into the terminal Phase.DESTROYED phase.
DefaultQualifierAndValue	Describes a Qualifier type annotation associated with a service being provided or dependant upon.
DefaultQualifierAndValue.Builder	The fluent builder.
DependenciesInfo	Represents a per ServiceInfo mapping of DependencyInfo's.
DependenciesInfo.Comparator	Comparator appropriate for DependencyInfo.
DependencyInfo	Aggregates the set of InjectionPointInfo's that are dependent upon a specific and common ServiceInfo definition.
ElementInfo	Abstractly describes method or field elements of a managed service type (i.e., fields, constructors, injectable methods, etc.).
ElementInfo.Access	The access describing the target injection point.
ElementInfo.ElementKind	The kind of injection target.
Event	A lifecycle activation event.
ExternalContracts	Placed on the implementation of a service as an alternative to using a Contract.
InjectionException	Represents an injection exception.
InjectionPointInfo	Describes a receiver for injection - identifies who/what is requesting an injection that needs to be satisfied.
InjectionPointProvider<T>	Provides ability to contextualize the injected service by the target receiver of the injection point dynamically at runtime.
Injector	Used to perform programmatic activation and injection.
Injector.Strategy	The strategy the injector should attempt to apply.
InjectorOptions	Provides optional, contextual tunings to the Injector.
Intercepted	Indicates that type identified by Intercepted.value() is being intercepted.
InterceptedTrigger	Meta-annotation for an annotation that will trigger services annotated with it to become intercepted.
Interceptor	Implementors of this contract must be Named according to the Intercepted annotation they support.
Interceptor.Chain<V>	Represents the next in line for interception, terminating with a call to the wrapped service provider.
InvocationContext	Used by Interceptor.
InvocationException	Wraps any checked exceptions that are thrown during the Interceptor invocations.
Metrics	Pico Metrics.
Module	Provides aggregation of services to the "containing" (jar) module.
OptionallyNamed	Provides a means to identify if the instance is optionally named.
Phase	Forms a progression of full activation and deactivation.
PicoException	A general exception indicating that something failed related to Pico.
PicoServiceProviderException	An exception relative to a ServiceProvider.
PicoServices	Abstract factory for all services provided by a single Helidon Pico provider implementation.
PicoServicesConfig	This is the configuration that the Pico service provider uses internally.
PicoServicesHolder	The holder for the globally active PicoServices singleton instance, as well as its associated Bootstrap primordial configuration.
PostConstructMethod	Represents the PostConstruct method.
PreDestroyMethod	Represents the PreDestroy method.
QualifierAndValue	Represents a tuple of the Qualifier and optionally any value.
Resettable	Implementors of this contract are capable of resetting the state of itself (i.e., clears cache, log entries, etc.).
RunLevel	Indicates the desired startup sequence for a service class.
ServiceBinder	Responsible for binding service providers to the service registry.
ServiceInfo	Describes a managed service or injection point.
ServiceInfoBasics	Basic service info that describes a service provider type.
ServiceInfoCriteria	Criteria to discover services.
ServiceInjectionPlanBinder	Responsible for registering the injection plan to the services in the service registry.
ServiceInjectionPlanBinder.Binder	The binder builder for the service plan.
ServiceProvider<T>	Provides management lifecycle around services.
ServiceProviderBindable<T>	An extension to ServiceProvider that allows for startup binding from a Pico$$Application, and thereby works in conjunction with the ServiceBinder during pico service registry initialization.
ServiceProviderProvider	Instances of these provide lists and maps of ServiceProviders.
Services	The service registry.