Package org.elasticsearch.common.inject

Class Key<T>

java.lang.Object
org.elasticsearch.common.inject.Key<T>
public class Key<T> extends 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.

  • Constructor Details

    • Key

      protected Key(Class<? extends 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(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>() {}.

  • Method Details

    • getTypeLiteral

      public final TypeLiteral<T> getTypeLiteral()
      Gets the key type.

    • getAnnotationType

      public final Class<? extends Annotation> getAnnotationType()
      Gets the annotation type.

    • getAnnotation

      public final Annotation getAnnotation()
      Gets the annotation.

    • equals

      public final boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public final int hashCode()
      Overrides:
      hashCode in class Object

    • toString

      public final String toString()
      Overrides:
      toString in class Object

    • get

      public static <T> Key<T> get(Class<T> type)
      Gets a key for an injection type.

    • get

      public static <T> Key<T> get(Class<T> type, Class<? extends Annotation> annotationType)
      Gets a key for an injection type and an annotation type.

    • get

      public static <T> Key<T> get(Class<T> type, Annotation annotation)
      Gets a key for an injection type and an annotation.

    • get

      public static Key<?> get(Type type)
      Gets a key for an injection type.

    • get

      public static Key<?> get(Type type, Class<? extends Annotation> annotationType)
      Gets a key for an injection type and an annotation type.

    • get

      public static Key<?> get(Type type, 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, Class<? extends Annotation> annotationType)
      Gets a key for an injection type and an annotation type.

    • get

      public static <T> Key<T> get(TypeLiteral<T> typeLiteral, Annotation annotation)
      Gets a key for an injection type and an annotation.