1*f585d8a3SJacky Wang /* 2*f585d8a3SJacky Wang * Copyright (C) 2015 The Dagger Authors. 3*f585d8a3SJacky Wang * 4*f585d8a3SJacky Wang * Licensed under the Apache License, Version 2.0 (the "License"); 5*f585d8a3SJacky Wang * you may not use this file except in compliance with the License. 6*f585d8a3SJacky Wang * You may obtain a copy of the License at 7*f585d8a3SJacky Wang * 8*f585d8a3SJacky Wang * http://www.apache.org/licenses/LICENSE-2.0 9*f585d8a3SJacky Wang * 10*f585d8a3SJacky Wang * Unless required by applicable law or agreed to in writing, software 11*f585d8a3SJacky Wang * distributed under the License is distributed on an "AS IS" BASIS, 12*f585d8a3SJacky Wang * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13*f585d8a3SJacky Wang * See the License for the specific language governing permissions and 14*f585d8a3SJacky Wang * limitations under the License. 15*f585d8a3SJacky Wang */ 16*f585d8a3SJacky Wang 17*f585d8a3SJacky Wang package dagger.multibindings; 18*f585d8a3SJacky Wang 19*f585d8a3SJacky Wang import static java.lang.annotation.ElementType.METHOD; 20*f585d8a3SJacky Wang import static java.lang.annotation.RetentionPolicy.RUNTIME; 21*f585d8a3SJacky Wang 22*f585d8a3SJacky Wang import java.lang.annotation.Documented; 23*f585d8a3SJacky Wang import java.lang.annotation.Retention; 24*f585d8a3SJacky Wang import java.lang.annotation.Target; 25*f585d8a3SJacky Wang 26*f585d8a3SJacky Wang /** 27*f585d8a3SJacky Wang * Annotates abstract module methods that declare multibindings. 28*f585d8a3SJacky Wang * 29*f585d8a3SJacky Wang * <p>You can declare that a multibound set or map is bound by annotating an abstract module method 30*f585d8a3SJacky Wang * that returns the set or map you want to declare with {@code @Multibinds}. 31*f585d8a3SJacky Wang * 32*f585d8a3SJacky Wang * <p>You do not have to use {@code @Multibinds} for sets or maps that have at least one 33*f585d8a3SJacky Wang * contribution, but you do have to declare them if they may be empty. 34*f585d8a3SJacky Wang * 35*f585d8a3SJacky Wang * <pre><code> 36*f585d8a3SJacky Wang * {@literal @Module} abstract class MyModule { 37*f585d8a3SJacky Wang * {@literal @Multibinds abstract Set<Foo> aSet();} 38*f585d8a3SJacky Wang * {@literal @Multibinds abstract @MyQualifier Set<Foo> aQualifiedSet();} 39*f585d8a3SJacky Wang * {@literal @Multibinds abstract Map<String, Foo> aMap();} 40*f585d8a3SJacky Wang * {@literal @Multibinds abstract @MyQualifier Map<String, Foo> aQualifiedMap();} 41*f585d8a3SJacky Wang * 42*f585d8a3SJacky Wang * {@literal @Provides} 43*f585d8a3SJacky Wang * {@literal static Object usesMultibindings(Set<Foo> set, @MyQualifier Map<String, Foo> map}) { 44*f585d8a3SJacky Wang * return … 45*f585d8a3SJacky Wang * } 46*f585d8a3SJacky Wang * }</code></pre> 47*f585d8a3SJacky Wang * 48*f585d8a3SJacky Wang * <p>A given set or map multibinding can be declared any number of times without error. Dagger 49*f585d8a3SJacky Wang * never implements or calls any {@code @Multibinds} methods. 50*f585d8a3SJacky Wang * 51*f585d8a3SJacky Wang * @see <a href="https://dagger.dev/multibindings">Multibindings</a> 52*f585d8a3SJacky Wang */ 53*f585d8a3SJacky Wang @Documented 54*f585d8a3SJacky Wang @Target(METHOD) 55*f585d8a3SJacky Wang @Retention(RUNTIME) 56*f585d8a3SJacky Wang public @interface Multibinds {} 57