2 * Copyright (c) 2014, 2015 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
9 package org.opendaylight.restconf.nb.rfc8040.streams.websockets;
11 import com.google.common.base.Preconditions;
12 import io.netty.bootstrap.ServerBootstrap;
13 import io.netty.channel.Channel;
14 import io.netty.channel.EventLoopGroup;
15 import io.netty.channel.nio.NioEventLoopGroup;
16 import io.netty.channel.socket.nio.NioServerSocketChannel;
17 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.Notificator;
18 import org.slf4j.Logger;
19 import org.slf4j.LoggerFactory;
22 * {@link WebSocketServer} is the singleton responsible for starting and stopping the
25 public final class WebSocketServer implements Runnable {
27 private static final Logger LOG = LoggerFactory.getLogger(WebSocketServer.class);
29 private static WebSocketServer instance = null;
31 private final int port;
33 private EventLoopGroup bossGroup;
34 private EventLoopGroup workerGroup;
37 private WebSocketServer(final int port) {
42 * Create singleton instance of {@link WebSocketServer}.
44 * @param port TCP port used for this server
45 * @return instance of {@link WebSocketServer}
47 public static WebSocketServer createInstance(final int port) {
48 Preconditions.checkState(instance == null, "createInstance() has already been called");
49 Preconditions.checkArgument(port >= 1024, "Privileged port (below 1024) is not allowed");
51 instance = new WebSocketServer(port);
56 * Get the websocket of TCP port.
58 * @return websocket TCP port
60 public int getPort() {
65 * Get instance of {@link WebSocketServer} created by {@link #createInstance(int)}.
67 * @return instance of {@link WebSocketServer}
69 public static WebSocketServer getInstance() {
70 Preconditions.checkNotNull(instance, "createInstance() must be called prior to getInstance()");
75 * Destroy the existing instance.
77 public static void destroyInstance() {
78 Preconditions.checkState(instance != null, "createInstance() must be called prior to destroyInstance()");
85 @SuppressWarnings("checkstyle:IllegalCatch")
87 bossGroup = new NioEventLoopGroup();
88 workerGroup = new NioEventLoopGroup();
90 final ServerBootstrap serverBootstrap = new ServerBootstrap();
91 serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)
92 .childHandler(new WebSocketServerInitializer());
94 final Channel channel = serverBootstrap.bind(port).sync().channel();
95 LOG.info("Web socket server started at port {}.", port);
97 channel.closeFuture().sync();
98 } catch (final InterruptedException e) {
99 LOG.error("Web socket server encountered an error during startup attempt on port {}", port, e);
100 } catch (Throwable throwable) {
101 // sync() re-throws exceptions declared as Throwable, so the compiler doesn't see them
102 LOG.error("Error while binding to port {}", port, throwable);
110 * Stops the web socket server and removes all listeners.
112 private void stop() {
113 LOG.debug("Stopping the web socket server instance on port {}", port);
114 Notificator.removeAllListeners();
115 if (bossGroup != null) {
116 bossGroup.shutdownGracefully();
119 if (workerGroup != null) {
120 workerGroup.shutdownGracefully();