/** | |
* 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. | |
* <p> | |
* Although MapBinders may be injected through a variety of generic types (Map{@literal<}K, V>, Map | |
* {@literal<}K, Provider{@literal<}V>>, Map{@literal<}K, Set{@literal<}V>>, Map<K, Set{@literal<} | |
* Provider{@literal<}V>>, and even Set{@literal<}Map.Entry{@literal<}K, Provider{@literal<}V>>), a | |
* MapBinderBinding exists only on the Binding associated with the Map{@literal<}K, V> key. Other | |
* bindings can be validated to be derived from this MapBinderBinding using | |
* {@link #containsElement(Element)}. | |
* | |
* @param <T> The fully qualified type of the map, including Map. For example: | |
* <code>MapBinderBinding{@literal<}Map{@literal<}String, Snack>></code> | |
* | |
* @author sameb@google.com (Sam Berlin) | |
*/ | |
public interface MapBinderBinding<T> { | |
/** Returns the {@link Key} for the map. */ | |
Key<T> getMapKey(); | |
/** | |
* Returns the TypeLiteral describing the keys of the map. | |
* <p> | |
* The TypeLiteral will always match the type Map's generic type. For example, if getMapKey | |
* returns a key of <code>Map{@literal<}String, Snack></code>, then this will always return a | |
* <code>TypeLiteral{@literal<}String></code>. | |
*/ | |
TypeLiteral<?> getKeyTypeLiteral(); | |
/** | |
* Returns the TypeLiteral describing the values of the map. | |
* <p> | |
* The TypeLiteral will always match the type Map's generic type. For example, if getMapKey | |
* returns a key of <code>Map{@literal<}String, Snack></code>, then this will always return a | |
* <code>TypeLiteral{@literal<}Snack></code>. | |
*/ | |
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}. | |
* <p> | |
* The elements will always match the type Map's generic type. For example, if getMapKey returns a | |
* key of <code>Map{@literal<}String, Snack></code>, then this will always return a list of type | |
* <code>List{@literal<}Map.Entry{@literal<}String, Binding{@literal<}Snack>>></code>. | |
*/ | |
List<Map.Entry<?, Binding<?>>> 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. | |
* <p> | |
* 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); | |
} |