Java tutorial
/** * 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 com.alibaba.rocketmq.storm.internal.tools; import backtype.storm.Config; import com.alibaba.rocketmq.storm.domain.RocketMQConfig; import org.apache.commons.lang.BooleanUtils; import java.io.IOException; import java.io.InputStream; import java.util.Map.Entry; import java.util.Properties; /** * Utilities for RocketMQ spout regarding its configuration and reading values * from the storm configuration. * * @author Von Gosling */ public abstract class ConfigUtils { /** * Storm configuration key pointing to a file containing rocketmq * configuration ({@code "rocketmq.config"}). */ public static final String CONFIG_FILE = "rocketmq.config"; /** * Storm configuration key used to determine the rocketmq topic to read from * ( {@code "rocketmq.spout.topic"}). */ public static final String CONFIG_TOPIC = "rocketmq.spout.topic"; /** * Default rocketmq topic to read from ({@code "rocketmq_spout_topic"}). */ public static final String CONFIG_DEFAULT_TOPIC = "rocketmq_spout_topic"; /** * Storm configuration key used to determine the rocketmq consumer group ( * {@code "rocketmq.spout.consumer.group"}). */ public static final String CONFIG_CONSUMER_GROUP = "rocketmq.spout.consumer.group"; /** * Default rocketmq consumer group id ( * {@code "rocketmq_spout_consumer_group"}). */ public static final String CONFIG_DEFAULT_CONSUMER_GROUP = "rocketmq_spout_consumer_group"; /** * Storm configuration key used to determine the rocketmq topic tag( * {@code "rocketmq.spout.topic.tag"}). */ public static final String CONFIG_TOPIC_TAG = "rocketmq.spout.topic.tag"; public static final String CONFIG_ROCKETMQ = "rocketmq.config"; public static final String CONFIG_PREFETCH_SIZE = "rocketmq.prefetch.size"; /** * Reads configuration from a classpath resource stream obtained from the * current thread's class loader through * {@link ClassLoader#getSystemResourceAsStream(String)}. * * @param resource The resource to be read. * @return A {@link java.util.Properties} object read from the specified * resource. * @throws IllegalArgumentException When the configuration file could not be * found or another I/O error occurs. */ public static Properties getResource(final String resource) { InputStream input = Thread.currentThread().getContextClassLoader().getResourceAsStream(resource); if (input == null) { throw new IllegalArgumentException("configuration file '" + resource + "' not found on classpath"); } final Properties config = new Properties(); try { config.load(input); } catch (final IOException e) { throw new IllegalArgumentException("reading configuration from '" + resource + "' failed", e); } return config; } public static Config init(String configFile) { Config config = new Config(); //1. Properties prop = ConfigUtils.getResource(configFile); for (Entry<Object, Object> entry : prop.entrySet()) { config.put((String) entry.getKey(), entry.getValue()); } //2. String topic = (String) config.get(ConfigUtils.CONFIG_TOPIC); String consumerGroup = (String) config.get(ConfigUtils.CONFIG_CONSUMER_GROUP); String topicTag = (String) config.get(ConfigUtils.CONFIG_TOPIC_TAG); //Integer pullBatchSize = (Integer) config.get(ConfigUtils.CONFIG_PREFETCH_SIZE); Integer pullBatchSize = Integer.parseInt((String) config.get(ConfigUtils.CONFIG_PREFETCH_SIZE)); RocketMQConfig mqConfig = new RocketMQConfig(consumerGroup, topic, topicTag); if (pullBatchSize != null && pullBatchSize > 0) { mqConfig.setPullBatchSize(pullBatchSize); } boolean ordered = BooleanUtils .toBooleanDefaultIfNull(Boolean.valueOf((String) (config.get("rocketmq.spout.ordered"))), false); mqConfig.setOrdered(ordered); config.put(CONFIG_ROCKETMQ, mqConfig); return config; } private ConfigUtils() { } }