websocket/websocket-client/src/main/java/org/opendaylight/yangtools/websocket/client/WebSocketIClient.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   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
   7  */
   8 package org.opendaylight.yangtools.websocket.client;
   9
  10 import io.netty.bootstrap.Bootstrap;
  11 import io.netty.buffer.Unpooled;
  12 import io.netty.channel.Channel;
  13 import io.netty.channel.ChannelInitializer;
  14 import io.netty.channel.ChannelPipeline;
  15 import io.netty.channel.EventLoopGroup;
  16 import io.netty.channel.nio.NioEventLoopGroup;
  17 import io.netty.channel.socket.SocketChannel;
  18 import io.netty.channel.socket.nio.NioSocketChannel;
  19 import io.netty.handler.codec.http.HttpClientCodec;
  20 import io.netty.handler.codec.http.HttpObjectAggregator;
  21 import io.netty.handler.codec.http.websocketx.CloseWebSocketFrame;
  22 import io.netty.handler.codec.http.websocketx.PingWebSocketFrame;
  23 import io.netty.handler.codec.http.websocketx.PongWebSocketFrame;
  24 import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
  25 import io.netty.handler.codec.http.websocketx.WebSocketClientHandshakerFactory;
  26 import io.netty.handler.codec.http.websocketx.WebSocketVersion;
  27
  28 import java.net.URI;
  29
  30 import org.opendaylight.yangtools.websocket.client.callback.ClientMessageCallback;
  31 import org.slf4j.Logger;
  32 import org.slf4j.LoggerFactory;
  33
  34 /**
  35  * Implementation of web socket client that supports WS and HTTP protocols.
  36  */
  37 public class WebSocketIClient {
  38
  39     private final URI uri;
  40     private Bootstrap bootstrap = new Bootstrap();;
  41     private final WebSocketClientHandler clientHandler;
  42     private static final Logger logger = LoggerFactory
  43             .getLogger(WebSocketIClient.class);
  44     private Channel clientChannel;
  45     private final EventLoopGroup group = new NioEventLoopGroup();
  46
  47     /**
  48      * Creates new web socket client
  49      *
  50      * @param uri
  51      *            URI
  52      * @param clientMessageCallback
  53      *            ClientMessageCallback
  54      */
  55     public WebSocketIClient(URI uri, ClientMessageCallback clientMessageCallback) {
  56         this.uri = uri;
  57         clientHandler = new WebSocketClientHandler(
  58                 WebSocketClientHandshakerFactory.newHandshaker(uri,
  59                         WebSocketVersion.V13, null, false, null),
  60                 clientMessageCallback); // last null could be replaced with
  61                                         // DefaultHttpHeaders
  62         initialize();
  63     }
  64
  65     /**
  66      * Initializes {@link Channel} one when it was registered to its
  67      * {@link EventLoop}.
  68      */
  69     private void initialize() {
  70
  71         String protocol = uri.getScheme();
  72         if (!"ws".equals(protocol) && !"http".equals(protocol)) {
  73             throw new IllegalArgumentException("Unsupported protocol: "
  74                     + protocol);
  75         }
  76
  77         bootstrap.group(group).channel(NioSocketChannel.class)
  78                 .handler(new ChannelInitializer<SocketChannel>() {
  79                     @Override
  80                     public void initChannel(SocketChannel ch) throws Exception {
  81                         ChannelPipeline pipeline = ch.pipeline();
  82                         pipeline.addLast("http-codec", new HttpClientCodec());
  83                         pipeline.addLast("aggregator",
  84                                 new HttpObjectAggregator(8192));
  85                         pipeline.addLast("ws-handler", clientHandler);
  86                     }
  87                 });
  88     }
  89
  90     /**
  91      * Makes the connection attempt and notifies when the handshake process
  92      * succeeds or fail.
  93      */
  94     public void connect() throws InterruptedException {
  95         clientChannel = bootstrap.connect(uri.getHost(), uri.getPort()).sync()
  96                 .channel();
  97         clientHandler.handshakeFuture().sync();
  98     }
  99
 100     /**
 101      * Writes a String message via {@link ChannelOutboundInvoker} through the
 102      * {@link ChannelPipeline} and request to actual {@link #flush()} to flush
 103      * all pending data to the actual transport.
 104      *
 105      * @param message
 106      *            a message to write
 107      */
 108     public void writeAndFlush(String message) {
 109         clientChannel.writeAndFlush(new TextWebSocketFrame(message));
 110     }
 111
 112     /**
 113      * Writes a Object message via {@link ChannelOutboundInvoker} through the
 114      * {@link ChannelPipeline} and request to actual {@link #flush()} to flush
 115      * all pending data to the actual transport.
 116      *
 117      * @param message
 118      *            a message to write
 119      */
 120     public void writeAndFlush(Object message) {
 121         clientChannel.writeAndFlush(message);
 122     }
 123
 124     /**
 125      * Writes {@link PingWebSocketFrame} via {@link ChannelOutboundInvoker}
 126      * through the {@link ChannelPipeline} and request to actual
 127      * {@link #flush()} to flush all pending data to the actual transport.
 128      */
 129     public void ping() {
 130         clientChannel.writeAndFlush(new PingWebSocketFrame(Unpooled
 131                 .copiedBuffer(new byte[] { 1, 2, 3, 4, 5, 6 })));
 132     }
 133
 134     /**
 135      * Closes the connection when the server responds to the
 136      * {@link CloseWebSocketFrame}.
 137      */
 138     public void close() throws InterruptedException {
 139         clientChannel.writeAndFlush(new CloseWebSocketFrame());
 140         clientChannel.closeFuture().sync();
 141         group.shutdownGracefully();
 142     }
 143
 144 }