com.google.inject.multibindings.MapBinderBinding Maven / Gradle / Ivy
/**
* Copyright (C) 2010 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.inject.multibindings;
import java.util.List;
import java.util.Map;
import com.google.inject.Binding;
import com.google.inject.Key;
import com.google.inject.TypeLiteral;
import com.google.inject.spi.Element;
import com.google.inject.spi.Elements;
/**
* A binding for a MapBinder.
*
* Although MapBinders may be injected through a variety of generic types (Map<K, V>, Map
* <K, Provider<V>>, Map<K, Set<V>>, Map>, and even Set<Map.Entry<K, Provider<V>>), a
* MapBinderBinding exists only on the Binding associated with the Map<K, V> key. Other
* bindings can be validated to be derived from this MapBinderBinding using
* {@link #containsElement(Element)}.
*
* @param The fully qualified type of the map, including Map. For example:
* MapBinderBinding<Map<String, Snack>>
*
* @since 3.0
* @author [email protected] (Sam Berlin)
*/
public interface MapBinderBinding {
/** Returns the {@link Key} for the map. */
Key getMapKey();
/**
* Returns the TypeLiteral describing the keys of the map.
*
* The TypeLiteral will always match the type Map's generic type. For example, if getMapKey
* returns a key of Map<String, Snack>, then this will always return a
* TypeLiteral<String>.
*/
TypeLiteral getKeyTypeLiteral();
/**
* Returns the TypeLiteral describing the values of the map.
*
* The TypeLiteral will always match the type Map's generic type. For example, if getMapKey
* returns a key of Map<String, Snack>, then this will always return a
* TypeLiteral<Snack>.
*/
TypeLiteral getValueTypeLiteral();
/**
* Returns all entries in the Map. The returned list of Map.Entries contains the key and a binding
* to the value. Duplicate keys or values will exist as separate Map.Entries in the returned list.
* This is only supported on bindings returned from an injector. This will throw
* {@link UnsupportedOperationException} if it is called on an element retrieved from
* {@link Elements#getElements}.
*
* The elements will always match the type Map's generic type. For example, if getMapKey returns a
* key of Map<String, Snack>, then this will always return a list of type
* List<Map.Entry<String, Binding<Snack>>>.
*/
List>> getEntries();
/**
* Returns true if the MapBinder permits duplicates. This is only supported on bindings returned
* from an injector. This will throw {@link UnsupportedOperationException} if it is called on a
* MapBinderBinding retrieved from {@link Elements#getElements}.
*/
boolean permitsDuplicates();
/**
* Returns true if this MapBinder contains the given Element in order to build the map or uses the
* given Element in order to support building and injecting the map. This will work for
* MapBinderBindings retrieved from an injector and {@link Elements#getElements}. Usually this is
* only necessary if you are working with elements retrieved from modules (without an Injector),
* otherwise {@link #getEntries} and {@link #permitsDuplicates} are better options.
*
* If you need to introspect the details of the map, such as the keys, values or if it permits
* duplicates, it is necessary to pass the elements through an Injector and use
* {@link #getEntries()} and {@link #permitsDuplicates()}.
*/
boolean containsElement(Element element);
}