gwenshap commented on a change in pull request #9367: URL: https://github.com/apache/kafka/pull/9367#discussion_r502083707
########## File path: clients/src/main/java/org/apache/kafka/common/utils/ConfigUtils.java ########## @@ -0,0 +1,92 @@ +/* + * 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.utils; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.List; +import java.util.Map; +import java.util.Objects; +import java.util.Set; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +public class ConfigUtils { + + private static final Logger log = LoggerFactory.getLogger(ConfigUtils.class); + + /** + * Translates deprecated configurations into their non-deprecated equivalents + * + * @param configs the input configuration + * @param aliasGroups An array of arrays of synonyms. Each synonym array begins with the non-deprecated synonym + * For example, new String[][] { { a, b }, { c, d, e} } + * would declare b as a deprecated synonym for a, + * and d and e as deprecated synonyms for c. + * @return a new configuration map with deprecated keys translated to their non-deprecated equivalents + */ + public static <T> Map<String, T> translateDeprecatedConfigs(Map<String, T> configs, String[][] aliasGroups) { + Set<String> aliasSet = Stream.of(aliasGroups).flatMap(Stream::of).collect(Collectors.toSet()); + + // pass through all configurations without aliases + Map<String, T> newConfigs = configs.entrySet().stream() + .filter(e -> !aliasSet.contains(e.getKey())) + // filter out null values + .filter(e -> Objects.nonNull(e.getValue())) + .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)); + + Stream.of(aliasGroups).forEachOrdered(aliasGroup -> { + String target = aliasGroup[0]; + + List<String> deprecated = Stream.of(aliasGroup) + .skip(1) // skip target + .filter(configs::containsKey) + .collect(Collectors.toList()); + + if (deprecated.isEmpty()) { + // No deprecated key(s) found. + if (configs.containsKey(target)) { + newConfigs.put(target, configs.get(target)); + } + return; + } + + String aliasString = String.join(", ", deprecated); + + if (configs.containsKey(target)) { + // Ignore the deprecated key(s) because the actual key was set. + log.error(target + " was configured, as well as the deprecated alias(es) " + + aliasString + ". Using the value of " + target); + newConfigs.put(target, configs.get(target)); + } else if (deprecated.size() > 1) { + log.error("The configuration keys " + aliasString + " are deprecated and may be " + Review comment: I like the extra-detailed error messages, thank you. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
