public interface


implements Provider<T><T>
Known Indirect Subclasses

Class Overview

An object capable of providing instances of type T. Providers are used in numerous ways by Guice:

  • When the default means for obtaining instances (an injectable or parameterless constructor) is insufficient for a particular binding, the module can specify a custom Provider instead, to control exactly how Guice creates or obtains instances for the binding.
  • An implementation class may always choose to have a Provider<T> instance injected, rather than having a T injected directly. This may give you access to multiple instances, instances you wish to safely mutate and discard, instances which are out of scope (e.g. using a @RequestScoped object from within a @SessionScoped object), or instances that will be initialized lazily.
  • A custom Scope is implemented as a decorator of Provider<T>, which decides when to delegate to the backing provider and when to provide the instance some other way.
  • The Injector offers access to the Provider<T> it uses to fulfill requests for a given key, via the getProvider(Key) methods.


Public Methods
abstract T get()
Provides an instance of T.
Inherited Methods
From interface javax.inject.Provider

Public Methods

public abstract T get ()

Provides an instance of T. Must never return null.

OutOfScopeException when an attempt is made to access a scoped object while the scope in question is not currently active
ProvisionException if an instance cannot be provided. Such exceptions include messages and throwables to describe why provision failed.