co.elastic.apm.api.HeadersExtractor Maven / Gradle / Ivy
/*-
* #%L
* Elastic APM Java agent
* %%
* Copyright (C) 2018 - 2020 Elastic and contributors
* %%
* Licensed to Elasticsearch B.V. under one or more contributor
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* 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
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*/
package co.elastic.apm.api;
/**
* Used to extract all header values with a specific header name.
*
* Useful for protocols such as HTTP which allow that a header can have multiple values.
*
*
* Can be implemented as a lambda in Java 8 and as an anonymous inner class in Java 7.
*
*/
public interface HeadersExtractor {
/**
* Returns all values of the provided header name
*
* @param headerName the name of the header to extract
* @return all values of the provided header name
*/
Iterable getAllHeaders(String headerName);
}