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 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;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* A binding for a MapBinder.
*
* Although MapBinders may be injected through a variety of generic types ({@code Map},
* {@code Map}, {@code Map>}, {@code Map>}, {@code Map>}, and even {@code Set>}), a MapBinderBinding exists
* only on the Binding associated with the Map<K, V> key. Injectable map types can be discovered
* using {@link #getMapKey} (which will return the {@code Map} key), or{@link
* #getAlternateMapKeys} (which will return the other keys that can inject this data). 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: {@code
* MapBinderBinding>}
* @since 3.0
* @author [email protected] (Sam Berlin)
*/
public interface MapBinderBinding {
/** Returns the {@link Key} for the map. */
Key getMapKey();
/**
* Returns the keys of other bindings that represent this map. This will return an entry for
* {@code Map>}, {@code Map>}, {@code
* Map>>}, {@code Map>>},
* {@code Map>>}, {@code Map>>}, {@code Map}, and {@code Map}.
*
* @since 4.2.3
*/
Set> getAlternateMapKeys();
/**
* 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();
/**
* Similar to {@link #getEntries()}, but can be used on a MapBinderBinding retrieved from {@link
* Elements#getElements}.
*
* One way to use this is to pass in the results of {@link Elements#getElements} as the {@code
* elements} parameter.
*
*
This differs from {@link #getEntries()} in that it will return duplicates if they are
* present in the {@code elements} passed in. This does not run the normal Guice de-duplication
* that {@link #getEntries()} does.
*
* @throws IllegalArgumentException if the provided elements contain partial map entries. If the
* elements come from {@link Elements#getElements} on a module with a MapBinder, there will be
* a 1:1 relationship and no exception will be thrown.
* @since 4.2
*/
List>> getEntries(Iterable elements);
/**
* 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);
}