com.google.inject.multibindings.ProvidesIntoOptional Maven / Gradle / Ivy
/**
* Copyright (C) 2015 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 static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import com.google.inject.Module;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
/**
* Annotates methods of a {@link Module} to add items to a {@link Multibinder}.
* The method's return type and binding annotation determines what Optional this will
* contribute to. For example,
*
*
* {@literal @}ProvidesIntoOptional(DEFAULT)
* {@literal @}Named("url")
* String provideFooUrl(FooManager fm) { returm fm.getUrl(); }
*
* {@literal @}ProvidesIntoOptional(ACTUAL)
* {@literal @}Named("url")
* String provideBarUrl(BarManager bm) { return bm.getUrl(); }
*
*
* will set the default value of {@code @Named("url") Optional} to foo's URL,
* and then override it to bar's URL.
*
* @author [email protected] (Sam Berlin)
* @since 4.0
*/
@Documented
@Target(METHOD)
@Retention(RUNTIME)
public @interface ProvidesIntoOptional {
/**
* @since 4.0
*/
enum Type {
/** Corresponds to {@link OptionalBinder#setBinding}. */
ACTUAL,
/** Corresponds to {@link OptionalBinder#setDefault}. */
DEFAULT
}
/** Specifies if the binding is for the actual or default value. */
Type value();
}