org.springframework.kafka.listener.adapter.ReplyHeadersConfigurer Maven / Gradle / Ivy
/*
* Copyright 2018-2019 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.kafka.listener.adapter;
import java.util.Map;
import org.springframework.lang.Nullable;
/**
* A strategy for configuring which headers, if any, should be set in a reply message.
*
* @author Gary Russell
* @since 2.2
*
*/
@FunctionalInterface
public interface ReplyHeadersConfigurer {
/**
* Return true if the header should be copied to the reply message.
* {@link org.springframework.kafka.support.KafkaHeaders#CORRELATION_ID} will not be
* offered; it is always copied.
* {@link org.springframework.messaging.MessageHeaders#ID} and
* {@link org.springframework.messaging.MessageHeaders#TIMESTAMP} are never copied.
* {@code KafkaHeaders.RECEIVED*} headers are never copied.
* @param headerName the header name.
* @param headerValue the header value.
* @return true to copy.
*/
boolean shouldCopy(String headerName, Object headerValue);
/**
* A map of additional headers to add to the reply message.
* IMPORTANT: Any existing headers with the same name will be replaced by those
* returned by this method.
* @return the headers.
*/
@Nullable
default Map additionalHeaders() {
return null;
}
}