Module io.helidon.inject.api

Package io.helidon.inject.api

package io.helidon.inject.api

The Helidon Injection 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 injection processor and injectio 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.

• InjectionServices - suite of services that are typically delivered by the Injection 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).
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.
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.
CallingContextFactory	Factory for creating CallingContext and builders for the calling context.
ClassNamed	This annotation is effectively the same as Named where the Named.value() is a Class name instead of a String.
CommonQualifiers	Commonly used Qualifier types.
Contract	The Contract annotation is used to relay significance to the type that it annotates.
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.
DependencyInfoComparator	Comparator appropriate for DependencyInfo.
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.
Helidon	Deprecated. this type may have backward incompatible changes, as it is considered a preview feature of Helidon!
InjectionException	A general exception indicating that something failed related to Injection.
InjectionPointProvider<T>	Provides ability to contextualize the injected service by the target receiver of the injection point dynamically at runtime.
InjectionServiceProviderException	An exception relative to a ServiceProvider.
InjectionServices	Abstract factory for all services provided by a single Helidon Injection provider implementation.
InjectionServicesHolder	The holder for the globally active InjectionServices singleton instance, as well as its associated Bootstrap primordial configuration.
Injector	Used to perform programmatic activation and injection.
Injector.Strategy	The strategy the injector should attempt to apply.
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.
InvocationException	Wraps any checked exceptions that are thrown during the Interceptor invocations.
ModuleComponent	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.
PostConstructMethod	Represents the PostConstruct method.
PreDestroyMethod	Represents the PreDestroy method.
Qualifiers	Utility methods for qualifiers.
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.
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 Injection$$Application, and thereby works in conjunction with the ServiceBinder during injection service registry initialization.
ServiceProviderInjectionException	Represents an injection exception.
ServiceProviderProvider	Instances of these provide lists and maps of ServiceProviders.
Services	The service registry.
Startable	Some components may require start when Helidon is bootstrapped, such as WebServer (to open server sockets).