Java tutorial
/* * Copyright 2012 The Netty Project * * The Netty Project 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.greencheek.caching.herdcache.memcached.elasticacheconfig.server; import io.netty.bootstrap.ServerBootstrap; import io.netty.channel.*; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.SocketChannel; import io.netty.channel.socket.nio.NioServerSocketChannel; import io.netty.handler.logging.LogLevel; import io.netty.handler.logging.LoggingHandler; import org.greencheek.caching.herdcache.memcached.elasticacheconfig.annotations.ConfigMessage; import org.greencheek.caching.herdcache.memcached.elasticacheconfig.annotations.DelayConfigResponse; import org.greencheek.caching.herdcache.memcached.elasticacheconfig.annotations.SendAllMessages; import org.junit.rules.TestRule; import org.junit.runner.Description; import org.junit.runners.model.Statement; import java.io.IOException; import java.net.InetAddress; import java.net.ServerSocket; import java.util.concurrent.TimeUnit; /** * Echoes back any received data from a client. */ public final class StringServer implements TestRule { private final String[] message; private final EventLoopGroup bossGroup = new NioEventLoopGroup(1); private final EventLoopGroup workerGroup = new NioEventLoopGroup(); private volatile int port; private final TimeUnit startDelayUnit; private final long startDelay; public StringServer(String msg) { this(msg, -1, TimeUnit.SECONDS); } public StringServer(String msg, long startDelay, TimeUnit startDelayUnit) { this.message = new String[] { msg }; this.startDelay = startDelay; this.startDelayUnit = startDelayUnit; } public StringServer(String[] msg, long startDelay, TimeUnit startDelayUnit) { this.message = msg; this.startDelay = startDelay; this.startDelayUnit = startDelayUnit; } public int getPort() { return port; } /** * Override to set up your specific external resource. * * @throws if setup fails (which will disable {@code after} */ public void before(final String[] message, final TimeUnit delayUnit, final long delay, boolean sendAllMessages) { final ServerSocket socket = findFreePort(); final ChannelHandler sharedHandler = new StringBasedServerHandler(message, delayUnit, delay, sendAllMessages); // do nothing try { final ServerBootstrap b = new ServerBootstrap(); b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class) .option(ChannelOption.SO_BACKLOG, 100).option(ChannelOption.SO_SNDBUF, 100) .handler(new LoggingHandler(LogLevel.INFO)) .childHandler(new ChannelInitializer<SocketChannel>() { @Override public void initChannel(SocketChannel ch) throws Exception { ChannelPipeline p = ch.pipeline(); p.addLast(new ConfigGetClusterDecoder()); p.addLast(new LoggingHandler(LogLevel.INFO)); p.addLast(sharedHandler); } }); // Start the server. if (startDelay > 0) { port = getPortNoClose(socket); workerGroup.schedule(new Runnable() { @Override public void run() { try { port = getPort(socket); b.bind(port).sync(); outputStartedMessage(); } catch (InterruptedException e) { } } }, startDelay, startDelayUnit); } else { port = getPort(socket); try { b.bind(port).sync(); outputStartedMessage(); } catch (InterruptedException e) { } } } finally { } } private void outputStartedMessage() { System.out.println("==========="); System.out.println("ElastiCache Config Server started on port: " + port); System.out.println("==========="); System.out.flush(); } private void outputShutdownMessage() { System.out.println("==========="); System.out.println("ElastiCache Config Server shutdown on port: " + port); System.out.println("==========="); System.out.flush(); } /** * Override to tear down your specific external resource. */ public void after() { // do nothing // Shut down all event loops to terminate all threads. bossGroup.shutdownGracefully(); workerGroup.shutdownGracefully(); outputShutdownMessage(); } private ServerSocket findFreePort() { try { ServerSocket server = new ServerSocket(0, 1, InetAddress.getLoopbackAddress()); server.setReuseAddress(true); return server; } catch (IOException e) { throw new RuntimeException(e.getMessage()); } } private int getPortNoClose(ServerSocket server) { return server.getLocalPort(); } private int getPort(ServerSocket server) { int port = server.getLocalPort(); try { server.close(); } catch (IOException e) { } return port; } public Statement apply(final Statement base, final Description description) { final ConfigMessage message = description.getAnnotation(ConfigMessage.class); final DelayConfigResponse delayBy = description.getAnnotation(DelayConfigResponse.class); final SendAllMessages sendAll = description.getAnnotation(SendAllMessages.class); final boolean sendAllMessages = sendAll == null ? false : true; final TimeUnit delayUnit; final long delayedFor; final String[] messageToSend; if (message == null) { messageToSend = this.message; } else { String[] msg = message.message(); if (msg == null || msg.length == 0) { messageToSend = this.message; } else { messageToSend = msg; } } if (delayBy == null) { delayUnit = TimeUnit.SECONDS; delayedFor = -1; } else { delayUnit = delayBy.delayedForTimeUnit(); delayedFor = delayBy.delayFor(); } return new Statement() { @Override public void evaluate() throws Throwable { before(messageToSend, delayUnit, delayedFor, sendAllMessages); try { base.evaluate(); } finally { after(); } } }; } }