com.expediagroup.rhapsody.api.Header Maven / Gradle / Ivy
/**
* Copyright 2019 Expedia, Inc.
*
* 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
*
* 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 com.expediagroup.rhapsody.api;
import java.util.Collections;
import java.util.Map;
/**
* A data item may contain metadata associated with it that is not strictly a subset of information
* contained in the data item. Such information can be propagated on {@link Headed Headed} data
* items in a Header.
*/
@FunctionalInterface
public interface Header {
static Header empty() {
return Collections::emptyMap;
}
static Header fromMap(Map map) {
return () -> map;
}
/**
* Convert this Header to a String-to-String Map of attributes
*/
Map toMap();
}