com.google.inject

Class Scopes

java.lang.Object

com.google.inject.Scopes

public class Scopes
extends Object

Built-in scope implementations.

Author:

crazybob@google.com (Bob Lee)

Field Summary

Fields

Modifier and Type	Field and Description
static Scope	NO_SCOPE No scope; the same as not applying any scope at all.
static Scope	SINGLETON One instance per Injector.

Method Summary

Methods

Modifier and Type	Method and Description
static boolean	isCircularProxy(Object object) Returns true if the object is a proxy for a circular dependency, constructed by Guice because it encountered a circular dependency.
static boolean	isScoped(Binding<?> binding, Scope scope, Class<? extends Annotation> scopeAnnotation) Returns true if binding has the given scope.
static boolean	isSingleton(Binding<?> binding) Returns true if binding is singleton-scoped.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SINGLETON

public static final Scope SINGLETON

One instance per Injector. Also see @Singleton.

NO_SCOPE

public static final Scope NO_SCOPE

No scope; the same as not applying any scope at all. Each time the Injector obtains an instance of an object with "no scope", it injects this instance then immediately forgets it. When the next request for the same binding arrives it will need to obtain the instance over again.

This exists only in case a class has been annotated with a scope annotation such as @Singleton, and you need to override this to "no scope" in your binding.

Since:

2.0

Method Detail

isSingleton

public static boolean isSingleton(Binding<?> binding)

Returns true if binding is singleton-scoped. If the binding is a linked key binding and belongs to an injector (ie. it was retrieved via Injector.getBinding()), then this method will also true if the target binding is singleton-scoped.

Since:

3.0

isScoped

public static boolean isScoped(Binding<?> binding,
               Scope scope,
               Class<? extends Annotation> scopeAnnotation)

Returns true if binding has the given scope. If the binding is a linked key binding and belongs to an injector (ie. it was retrieved via Injector.getBinding()), then this method will also true if the target binding has the given scope.

Parameters:

binding - binding to check

scope - scope implementation instance

scopeAnnotation - scope annotation class

Since:

4.0

isCircularProxy

public static boolean isCircularProxy(Object object)

Returns true if the object is a proxy for a circular dependency, constructed by Guice because it encountered a circular dependency. Scope implementations should be careful to not cache circular proxies, because the proxies are not intended for general purpose use. (They are designed just to fulfill the immediate injection, not all injections. Caching them can lead to IllegalArgumentExceptions or ClassCastExceptions.)

Since:

4.0