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 org.apache.curator.x.rpc; import com.codahale.metrics.MetricRegistry; import com.facebook.swift.codec.ThriftCodecManager; import com.facebook.swift.service.ThriftEventHandler; import com.facebook.swift.service.ThriftServer; import com.facebook.swift.service.ThriftServiceProcessor; import com.google.common.base.Preconditions; import com.google.common.collect.Lists; import com.google.common.io.Files; import com.google.common.io.Resources; import org.apache.curator.x.rpc.configuration.Configuration; import org.apache.curator.x.rpc.configuration.ConfigurationBuilder; import org.apache.curator.x.rpc.connections.ConnectionManager; import org.apache.curator.x.rpc.idl.discovery.DiscoveryService; import org.apache.curator.x.rpc.idl.discovery.DiscoveryServiceLowLevel; import org.apache.curator.x.rpc.idl.services.EventService; import org.apache.curator.x.rpc.idl.services.CuratorProjectionService; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.File; import java.io.IOException; import java.net.URL; import java.nio.charset.Charset; import java.util.concurrent.atomic.AtomicReference; public class CuratorProjectionServer { private final Logger log = LoggerFactory.getLogger(getClass()); private final ConnectionManager connectionManager; private final ThriftServer server; private final AtomicReference<State> state = new AtomicReference<State>(State.LATENT); private final Configuration configuration; private enum State { LATENT, STARTED, STOPPED } public static void main(String[] args) throws Exception { if ((args.length != 1) || args[0].equalsIgnoreCase("?") || args[0].equalsIgnoreCase("-h") || args[0].equalsIgnoreCase("--help")) { printHelp(); return; } String configurationSource; File f = new File(args[0]); if (f.exists()) { configurationSource = Files.toString(f, Charset.defaultCharset()); } else { System.out.println("First argument is not a file. Treating the command line as a json/yaml object"); configurationSource = args[0]; } final CuratorProjectionServer server = startServer(configurationSource); Runnable shutdown = new Runnable() { @Override public void run() { server.stop(); } }; Thread hook = new Thread(shutdown); Runtime.getRuntime().addShutdownHook(hook); } public static CuratorProjectionServer startServer(String configurationSource) throws Exception { Configuration configuration = new ConfigurationBuilder(configurationSource).build(); final CuratorProjectionServer server = new CuratorProjectionServer(configuration); server.start(); return server; } public CuratorProjectionServer(Configuration configuration) { this.configuration = configuration; connectionManager = new ConnectionManager(configuration.getConnections(), configuration.getProjectionExpiration().toMillis()); EventService eventService = new EventService(connectionManager, configuration.getPingTime().toMillis()); DiscoveryService discoveryService = new DiscoveryService(connectionManager); CuratorProjectionService projectionService = new CuratorProjectionService(connectionManager); DiscoveryServiceLowLevel discoveryServiceLowLevel = new DiscoveryServiceLowLevel(connectionManager); ThriftServiceProcessor processor = new ThriftServiceProcessor(new ThriftCodecManager(), Lists.<ThriftEventHandler>newArrayList(), projectionService, eventService, discoveryService, discoveryServiceLowLevel); server = new ThriftServer(processor, configuration.getThrift()); } public void start() { Preconditions.checkState(state.compareAndSet(State.LATENT, State.STARTED), "Already started"); configuration.getLogging().configure(new MetricRegistry(), "curator-rpc"); connectionManager.start(); server.start(); log.info("Server listening on port: " + configuration.getThrift().getPort()); } public void stop() { if (state.compareAndSet(State.STARTED, State.STOPPED)) { log.info("Stopping..."); server.close(); connectionManager.close(); configuration.getLogging().stop(); log.info("Stopped"); } } private static void printHelp() throws IOException { URL helpUrl = Resources.getResource("curator/help.txt"); System.out.println(Resources.toString(helpUrl, Charset.defaultCharset())); System.out.println(); System.out.println("======= Curator Thrift IDL ======="); System.out.println(); URL idlUrl = Resources.getResource("curator.thrift"); System.out.println(Resources.toString(idlUrl, Charset.defaultCharset())); } }