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.twitter.distributedlog.service; import com.google.common.base.Function; import com.google.common.base.Optional; import com.twitter.distributedlog.DistributedLogConfiguration; import com.twitter.finagle.stats.NullStatsReceiver; import com.twitter.finagle.stats.StatsReceiver; import org.apache.bookkeeper.stats.NullStatsProvider; import org.apache.bookkeeper.stats.StatsProvider; import org.apache.bookkeeper.util.ReflectionUtils; import org.apache.commons.cli.BasicParser; import org.apache.commons.cli.CommandLine; import org.apache.commons.cli.HelpFormatter; import org.apache.commons.cli.Options; import org.apache.commons.cli.ParseException; import org.apache.commons.configuration.ConfigurationException; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.annotation.Nullable; import java.io.File; import java.io.IOException; import java.net.MalformedURLException; import java.util.Arrays; import static com.twitter.distributedlog.util.CommandLineUtils.*; public class DistributedLogServerApp { static final Logger logger = LoggerFactory.getLogger(DistributedLogServerApp.class); private final static String USAGE = "DistributedLogServerApp [-u <uri>] [-c <conf>]"; private final String[] args; private final Options options = new Options(); private DistributedLogServerApp(String[] args) { this.args = args; // prepare options options.addOption("u", "uri", true, "DistributedLog URI"); options.addOption("c", "conf", true, "DistributedLog Configuration File"); options.addOption("sc", "stream-conf", true, "Per Stream Configuration Directory"); options.addOption("p", "port", true, "DistributedLog Server Port"); options.addOption("sp", "stats-port", true, "DistributedLog Stats Port"); options.addOption("pd", "stats-provider", true, "DistributedLog Stats Provider"); options.addOption("si", "shard-id", true, "DistributedLog Shard ID"); options.addOption("a", "announce", false, "ServerSet Path to Announce"); options.addOption("mx", "thriftmux", false, "Is thriftmux enabled"); } private void printUsage() { HelpFormatter helpFormatter = new HelpFormatter(); helpFormatter.printHelp(USAGE, options); } private void run() { try { logger.info("Running distributedlog server : args = {}", Arrays.toString(args)); BasicParser parser = new BasicParser(); CommandLine cmdline = parser.parse(options, args); runCmd(cmdline); } catch (ParseException pe) { logger.error("Argument error : {}", pe.getMessage()); printUsage(); Runtime.getRuntime().exit(-1); } catch (IllegalArgumentException iae) { logger.error("Argument error : {}", iae.getMessage()); printUsage(); Runtime.getRuntime().exit(-1); } catch (ConfigurationException ce) { logger.error("Configuration error : {}", ce.getMessage()); printUsage(); Runtime.getRuntime().exit(-1); } catch (IOException ie) { logger.error("Failed to start distributedlog server : ", ie); Runtime.getRuntime().exit(-1); } } private void runCmd(CommandLine cmdline) throws IllegalArgumentException, IOException, ConfigurationException { final StatsReceiver statsReceiver = NullStatsReceiver.get(); Optional<String> confOptional = getOptionalStringArg(cmdline, "c"); DistributedLogConfiguration dlConf = new DistributedLogConfiguration(); if (confOptional.isPresent()) { String configFile = confOptional.get(); try { dlConf.loadConf(new File(configFile).toURI().toURL()); } catch (ConfigurationException e) { throw new IllegalArgumentException( "Failed to load distributedlog configuration from " + configFile + "."); } catch (MalformedURLException e) { throw new IllegalArgumentException( "Failed to load distributedlog configuration from malformed " + configFile + "."); } } // load the stats provider final StatsProvider statsProvider = getOptionalStringArg(cmdline, "pd") .transform(new Function<String, StatsProvider>() { @Nullable @Override public StatsProvider apply(@Nullable String name) { return ReflectionUtils.newInstance(name, StatsProvider.class); } }).or(new NullStatsProvider()); statsProvider.start(dlConf); final DistributedLogServer server = DistributedLogServer.runServer(getOptionalStringArg(cmdline, "u"), confOptional, getOptionalStringArg(cmdline, "sc"), getOptionalIntegerArg(cmdline, "p"), getOptionalIntegerArg(cmdline, "sp"), getOptionalIntegerArg(cmdline, "si"), getOptionalBooleanArg(cmdline, "a"), getOptionalBooleanArg(cmdline, "mx"), statsReceiver, statsProvider); Runtime.getRuntime().addShutdownHook(new Thread() { @Override public void run() { logger.info("Closing DistributedLog Server."); server.close(); logger.info("Closed DistributedLog Server."); statsProvider.stop(); } }); try { server.join(); } catch (InterruptedException e) { logger.warn("Interrupted when waiting distributedlog server to be finished : ", e); } logger.info("DistributedLog Service Interrupted."); server.close(); logger.info("Closed DistributedLog Server."); statsProvider.stop(); } public static void main(String[] args) { final DistributedLogServerApp launcher = new DistributedLogServerApp(args); launcher.run(); } }