| /** |
| * 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.storm.command; |
| |
| import java.util.List; |
| import java.util.Map; |
| import java.util.stream.Collectors; |
| import org.apache.storm.utils.ObjectReader; |
| import org.apache.storm.utils.Utils; |
| |
| /** |
| * Read a value from the topology config map. |
| */ |
| public final class ConfigValue { |
| |
| /** |
| * Utility classes should not have a public constructor. |
| */ |
| private ConfigValue() { |
| } |
| |
| /** |
| * Read the topology config and return the value for the given key. |
| * @param args - an array of length 1 containing the key to fetch. |
| */ |
| public static void main(final String[] args) { |
| String name = args[0]; |
| Map<String, Object> conf = Utils.readStormConfig(); |
| Object value = conf.get(name); |
| if (value instanceof List) { |
| List<String> stringValues = ((List<?>) value) |
| .stream() |
| .map(ObjectReader::getString) |
| .collect(Collectors.toList()); |
| value = String.join(" ", stringValues); |
| } |
| System.out.println("VALUE: " + value); |
| } |
| } |