javax.inject

Interface Provider<T>

All Known Subinterfaces:

Instance<T>

All Known Implementing Classes:

AbstractCDI, CDI, InstanceImpl, SimpleCDI

public interface Provider<T>

Provides instances of T. Typically implemented by an injector. For any type T that can be injected, you can also inject Provider<T>. Compared to injecting T directly, injecting Provider<T> enables:

• retrieving multiple instances.
• lazy or optional retrieval of an instance.
• breaking circular dependencies.
• abstracting scope so you can look up an instance in a smaller scope from an instance in a containing scope.

For example:

   class Car {
     @Inject Car(Provider<Seat> seatProvider) {
       Seat driver = seatProvider.get();
       Seat passenger = seatProvider.get();
       ...
     }
   }

Method Summary

Modifier and Type	Method and Description
T	get() Provides a fully-constructed and injected instance of T.

Method Detail

get

T get()

Provides a fully-constructed and injected instance of T.

Throws:

java.lang.RuntimeException - if the injector encounters an error while providing an instance. For example, if an injectable member on T throws an exception, the injector may wrap the exception and throw it to the caller of get(). Callers should not try to handle such exceptions as the behavior may vary across injector implementations and even different configurations of the same injector.