io.micronaut.http.annotation.Produces Maven / Gradle / Ivy
/*
* Copyright 2017-2020 original authors
*
* 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
*
* https://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 io.micronaut.http.annotation;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import io.micronaut.context.annotation.AliasFor;
import io.micronaut.core.async.annotation.SingleResult;
import io.micronaut.http.MediaType;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
/**
* An annotation to indicate the {@link MediaType}s produced by a particular component.
*
* Generally with controllers one can use the {@code produces} attribute of the {@code Controller} annotation,
* however this annotation is more generic and applies to any component
*
* @author Graeme Rocher
* @since 1.0
*/
@Documented
@Retention(RUNTIME)
@Target({ElementType.METHOD, ElementType.TYPE})
@Inherited
public @interface Produces {
/**
* @return The {@link MediaType} values that this component is able to produce
*/
String[] value() default MediaType.APPLICATION_JSON;
/**
* In the case of reactive types this member indicates whether only a single result is returned. Normally this
* annotation is unnecessary unless the declared type doesn't indicate how many items are emitted.
*
* For JSON with single = false if an Reactive streams Publisher type is returned these will be automatically
* wrapped in an Array type to ensure valid JSON is returned.
*
* If single = true it is expected that only a single result will be emitted and the result will not be wrapped
* in a JSON array.
*
* @return True if only a single result is emitted
*/
@AliasFor(annotation = SingleResult.class, member = "value")
boolean single() default false;
}