1 /* 2 * Copyright (C) 2015 The Dagger Authors. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package dagger.multibindings; 18 19 import static java.lang.annotation.RetentionPolicy.RUNTIME; 20 21 import dagger.MapKey; 22 import java.lang.annotation.Documented; 23 import java.lang.annotation.ElementType; 24 import java.lang.annotation.Retention; 25 import java.lang.annotation.Target; 26 27 /** 28 * A {@link MapKey} annotation for maps with {@code Class<?>} keys. 29 * 30 * <p>If your map's keys can be constrained, consider using a custom annotation instead, with a 31 * member whose type is {@code Class<? extends Something>}. 32 */ 33 @Documented 34 // While METHOD is the only valid target for Dagger, FIELD was added to support Hilt's 35 // @BindValueIntoMap and TYPE was added to support external extension types since it likely won't 36 // cause confusion/maintenance issues as this isn't part of Dagger's core API. 37 // See discussion on https://github.com/google/dagger/pull/2831#issuecomment-919417457 for details. 38 @Target({ElementType.METHOD, ElementType.FIELD, ElementType.TYPE}) 39 @Retention(RUNTIME) 40 @MapKey 41 public @interface ClassKey { value()42 Class<?> value(); 43 } 44