Package org.elasticsearch.common.inject

Class 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.

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected Key()
      Constructs a new key.
      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.

    • Method Summary

      Modifier and Type Method Description
      boolean equals​(java.lang.Object o)  
      static <T> Key<T> get​(java.lang.Class<T> type)
      Gets a key for an injection type.
      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.
      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.
      java.lang.annotation.Annotation getAnnotation()
      Gets the annotation.
      java.lang.Class<? extends java.lang.annotation.Annotation> getAnnotationType()
      Gets the annotation type.
      TypeLiteral<T> getTypeLiteral()
      Gets the key type.
      int hashCode()  
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

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

    • 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>() {}.

    • Method Detail

      • 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.

      • 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

        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.