org.apache.kafka.common.header.Headers Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.kafka.common.header;
public interface Headers extends Iterable {
/**
* Adds a header (key inside), to the end, returning if the operation succeeded.
*
* @param header the Header to be added
* @return this instance of the Headers, once the header is added.
* @throws IllegalStateException is thrown if headers are in a read-only state.
*/
Headers add(Header header) throws IllegalStateException;
/**
* Creates and adds a header, to the end, returning if the operation succeeded.
*
* @param key of the header to be added.
* @param value of the header to be added.
* @return this instance of the Headers, once the header is added.
* @throws IllegalStateException is thrown if headers are in a read-only state.
*/
Headers add(String key, byte[] value) throws IllegalStateException;
/**
* Removes all headers for the given key returning if the operation succeeded.
*
* @param key to remove all headers for.
* @return this instance of the Headers, once the header is removed.
* @throws IllegalStateException is thrown if headers are in a read-only state.
*/
Headers remove(String key) throws IllegalStateException;
/**
* Returns just one (the very last) header for the given key, if present.
*
* @param key to get the last header for.
* @return this last header matching the given key, returns none if not present.
*/
Header lastHeader(String key);
/**
* Returns all headers for the given key, in the order they were added in, if present.
*
* @param key to return the headers for.
* @return all headers for the given key, in the order they were added in, if NO headers are present an empty iterable is returned.
*/
Iterable headers(String key);
/**
* Returns all headers as an array, in the order they were added in.
*
* @return the headers as a Header[], mutating this array will not affect the Headers, if NO headers are present an empty array is returned.
*/
Header[] toArray();
}