org.springframework.messaging.handler.invocation.reactive.HandlerMethodReturnValueHandler Maven / Gradle / Ivy
/*
* Copyright 2002-2017 the original author or 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 org.springframework.messaging.handler.invocation.reactive;
import reactor.core.publisher.Mono;
import org.springframework.core.MethodParameter;
import org.springframework.lang.Nullable;
import org.springframework.messaging.Message;
/**
* Handle the return value from the invocation of an annotated {@link Message}
* handling method.
*
* @author Rossen Stoyanchev
* @since 5.2
*/
public interface HandlerMethodReturnValueHandler {
/** Header containing a DataBufferFactory for use in return value handling. */
String DATA_BUFFER_FACTORY_HEADER = "dataBufferFactory";
/**
* Whether the given {@linkplain MethodParameter method return type} is
* supported by this handler.
* @param returnType the method return type to check
* @return {@code true} if this handler supports the supplied return type;
* {@code false} otherwise
*/
boolean supportsReturnType(MethodParameter returnType);
/**
* Handle the given return value.
* @param returnValue the value returned from the handler method
* @param returnType the type of the return value. This type must have previously
* been passed to {@link #supportsReturnType(MethodParameter)}
* and it must have returned {@code true}.
* @return {@code Mono} to indicate when handling is complete.
*/
Mono handleReturnValue(@Nullable Object returnValue, MethodParameter returnType, Message message);
}