Package com.google.inject

Class Key<T>

java.lang.Object

com.google.inject.Key<T>

public class Key<T>
extends java.lang.Object

Binding key consisting of an injection type and an optional annotation. Matches the type and annotation at a point of injection.

For example, Key.get(Service.class, Transactional.class) will match:

   @Inject
   public void setService(@Transactional Service service) {
     ...
   }
 

Key supports generic types via subclassing just like TypeLiteral.

Keys do not differentiate between primitive types (int, char, etc.) and their corresponding wrapper types (Integer, Character, etc.). Primitive types will be replaced with their wrapper types when keys are created.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	Key.AnnotationInstanceStrategy
(package private) static interface	Key.AnnotationStrategy
(package private) static class	Key.AnnotationTypeStrategy
(package private) static class	Key.NullAnnotationStrategy

Field Summary

Fields

Modifier and Type	Field	Description
private Key.AnnotationStrategy	annotationStrategy
private int	hashCode
private java.lang.String	toString
private TypeLiteral<T>	typeLiteral

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Key()	Constructs a new key.
private	Key(TypeLiteral<T> typeLiteral, Key.AnnotationStrategy annotationStrategy)	Constructs a key from a manually specified type.
protected	Key(java.lang.annotation.Annotation annotation)	Constructs a new key.
protected	Key(java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)	Constructs a new key.
private	Key(java.lang.reflect.Type type, Key.AnnotationStrategy annotationStrategy)	Unsafe.

Method Summary

Modifier and Type	Method	Description
private int	computeHashCode()	Computes the hash code for this key.
private static void	ensureIsBindingAnnotation(java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)
private static void	ensureRetainedAtRuntime(java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)
boolean	equals(java.lang.Object o)
static <T> Key<T>	get(TypeLiteral<T> typeLiteral)	Gets a key for an injection type.
static <T> Key<T>	get(TypeLiteral<T> typeLiteral, java.lang.annotation.Annotation annotation)	Gets a key for an injection type and an annotation.
static <T> Key<T>	get(TypeLiteral<T> typeLiteral, java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)	Gets a key for an injection type and an annotation type.
static <T> Key<T>	get(java.lang.Class<T> type)	Gets a key for an injection type.
(package private) static <T> Key<T>	get(java.lang.Class<T> type, Key.AnnotationStrategy annotationStrategy)	Gets a key for an injection type and an annotation strategy.
static <T> Key<T>	get(java.lang.Class<T> type, java.lang.annotation.Annotation annotation)	Gets a key for an injection type and an annotation.
static <T> Key<T>	get(java.lang.Class<T> type, java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)	Gets a key for an injection type and an annotation type.
static Key<?>	get(java.lang.reflect.Type type)	Gets a key for an injection type.
static Key<?>	get(java.lang.reflect.Type type, java.lang.annotation.Annotation annotation)	Gets a key for an injection type and an annotation.
static Key<?>	get(java.lang.reflect.Type type, java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)	Gets a key for an injection type and an annotation type.
java.lang.annotation.Annotation	getAnnotation()	Gets the annotation.
(package private) java.lang.String	getAnnotationName()
java.lang.Class<? extends java.lang.annotation.Annotation>	getAnnotationType()	Gets the annotation type.
(package private) java.lang.Class<? super T>	getRawType()
TypeLiteral<T>	getTypeLiteral()	Gets the key type.
(package private) boolean	hasAnnotationType()
boolean	hasAttributes()	Returns true if this key has annotation attributes.
int	hashCode()
<T> Key<T>	ofType(TypeLiteral<T> type)	Returns a new key of the specified type with the same annotation as this key.
<T> Key<T>	ofType(java.lang.Class<T> type)	Returns a new key of the specified type with the same annotation as this key.
Key<?>	ofType(java.lang.reflect.Type type)	Returns a new key of the specified type with the same annotation as this key.
(package private) Key<Provider<T>>	providerKey()	Gets the key of this key's provider.
(package private) static Key.AnnotationStrategy	strategyFor(java.lang.annotation.Annotation annotation)	Gets the strategy for an annotation.
(package private) static Key.AnnotationStrategy	strategyFor(java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)	Gets the strategy for an annotation type.
java.lang.String	toString()
Key<T>	withoutAttributes()	Returns this key without annotation attributes, i.e.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

annotationStrategy

private final Key.AnnotationStrategy annotationStrategy

typeLiteral

private final TypeLiteral<T> typeLiteral

hashCode

private final int hashCode

toString

private java.lang.String toString

Constructor Detail

Key

protected Key(java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)

Constructs a new key. Derives the type from this class's type parameter.

Clients create an empty anonymous subclass. Doing so embeds the type parameter in the anonymous class's type hierarchy so we can reconstitute it at runtime despite erasure.

Example usage for a binding of type Foo annotated with @Bar:

new Key<Foo>(Bar.class) {}.

Key

protected Key(java.lang.annotation.Annotation annotation)

Constructs a new key. Derives the type from this class's type parameter.

Clients create an empty anonymous subclass. Doing so embeds the type parameter in the anonymous class's type hierarchy so we can reconstitute it at runtime despite erasure.

Example usage for a binding of type Foo annotated with @Bar:

new Key<Foo>(new Bar()) {}.

Key

protected Key()

Constructs a new key. Derives the type from this class's type parameter.

Clients create an empty anonymous subclass. Doing so embeds the type parameter in the anonymous class's type hierarchy so we can reconstitute it at runtime despite erasure.

Example usage for a binding of type Foo:

new Key<Foo>() {}.

Key

private Key(java.lang.reflect.Type type,
            Key.AnnotationStrategy annotationStrategy)

Unsafe. Constructs a key from a manually specified type.

Key

private Key(TypeLiteral<T> typeLiteral,
            Key.AnnotationStrategy annotationStrategy)

Constructs a key from a manually specified type.

Method Detail

computeHashCode

private int computeHashCode()

Computes the hash code for this key.

getTypeLiteral

public final TypeLiteral<T> getTypeLiteral()

Gets the key type.

getAnnotationType

public final java.lang.Class<? extends java.lang.annotation.Annotation> getAnnotationType()

Gets the annotation type.

getAnnotation

public final java.lang.annotation.Annotation getAnnotation()

Gets the annotation.

hasAnnotationType

boolean hasAnnotationType()

getAnnotationName

java.lang.String getAnnotationName()

getRawType

java.lang.Class<? super T> getRawType()

providerKey

Key<Provider<T>> providerKey()

Gets the key of this key's provider.

equals

public final boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public final int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public final java.lang.String toString()

Overrides:

toString in class java.lang.Object

get

static <T> Key<T> get(java.lang.Class<T> type,
                      Key.AnnotationStrategy annotationStrategy)

Gets a key for an injection type and an annotation strategy.

get

public static <T> Key<T> get(java.lang.Class<T> type)

Gets a key for an injection type.

get

public static <T> Key<T> get(java.lang.Class<T> type,
                             java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)

Gets a key for an injection type and an annotation type.

get

public static <T> Key<T> get(java.lang.Class<T> type,
                             java.lang.annotation.Annotation annotation)

Gets a key for an injection type and an annotation.

get

public static Key<?> get(java.lang.reflect.Type type)

Gets a key for an injection type.

get

public static Key<?> get(java.lang.reflect.Type type,
                         java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)

Gets a key for an injection type and an annotation type.

get

public static Key<?> get(java.lang.reflect.Type type,
                         java.lang.annotation.Annotation annotation)

Gets a key for an injection type and an annotation.

get

public static <T> Key<T> get(TypeLiteral<T> typeLiteral)

Gets a key for an injection type.

get

public static <T> Key<T> get(TypeLiteral<T> typeLiteral,
                             java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)

Gets a key for an injection type and an annotation type.

get

public static <T> Key<T> get(TypeLiteral<T> typeLiteral,
                             java.lang.annotation.Annotation annotation)

Gets a key for an injection type and an annotation.

ofType

public <T> Key<T> ofType(java.lang.Class<T> type)

Returns a new key of the specified type with the same annotation as this key.

Since:

3.0

ofType

public Key<?> ofType(java.lang.reflect.Type type)

Returns a new key of the specified type with the same annotation as this key.

Since:

3.0

ofType

public <T> Key<T> ofType(TypeLiteral<T> type)

Returns a new key of the specified type with the same annotation as this key.

Since:

3.0

hasAttributes

public boolean hasAttributes()

Returns true if this key has annotation attributes.

Since:

3.0

withoutAttributes

public Key<T> withoutAttributes()

Returns this key without annotation attributes, i.e. with only the annotation type.

Since:

3.0

strategyFor

static Key.AnnotationStrategy strategyFor(java.lang.annotation.Annotation annotation)

Gets the strategy for an annotation.

strategyFor

static Key.AnnotationStrategy strategyFor(java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)

Gets the strategy for an annotation type.

ensureRetainedAtRuntime

private static void ensureRetainedAtRuntime(java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)

ensureIsBindingAnnotation

private static void ensureIsBindingAnnotation(java.lang.Class<? extends java.lang.annotation.Annotation> annotationType)