/* | |
* 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 util; | |
import org.apache.nifi.util.StringUtils; | |
import java.util.AbstractMap; | |
import java.util.Arrays; | |
import java.util.List; | |
import java.util.Map; | |
import java.util.stream.Collectors; | |
public final class HeaderMapExtractor { | |
private HeaderMapExtractor(){ | |
// Utility class, not meant to be instantiated. | |
} | |
public static final String HEADER_PREFIX = "header."; | |
public static Map<String, List<String>> getHeaderMap(final Map<String, String> flowFileAttributes) { | |
return flowFileAttributes.entrySet().stream() | |
.filter(entry -> entry.getKey().startsWith(HEADER_PREFIX)) | |
.filter(entry -> StringUtils.isNotBlank(entry.getValue())) | |
.map(entry -> new AbstractMap.SimpleImmutableEntry<>(StringUtils.substringAfter(entry.getKey(), HEADER_PREFIX), entry.getValue())) | |
.collect(Collectors.toMap(Map.Entry::getKey, HeaderMapExtractor::headerValueMapper)); | |
} | |
private static List<String> headerValueMapper(Map.Entry<String, String> entry) { | |
return Arrays.stream(entry.getValue().split(",")).map(String::trim).collect(Collectors.toList()); | |
} | |
} |