Guice provides the @Inject annotation to indicate that a consumer is dependent on a particular dependency. The injector takes care of initializing this dependency using the object graph. Guice gets a hint from the annotation that it needs to participate in the class construction phase. The @Inject annotation can be utilized in a constructor for a class, for a method, or for a field. Consider the following code:
//Field level injection@Injectprivate NotificationService notificationService;//Constructor level Injection@Injectpublic AppConsumer(NotificationService service){ this.notificationService=service;}//Method level injection@Injectpublic void setService(NotificationService service) { this.notificationService = service;}
