Java tutorial
/* * Copyright (c) 2017, WSO2 Inc. (http://www.wso2.org) All Rights Reserved. * * WSO2 Inc. 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.ballerinalang.composer.service.workspace.composerapi; import io.netty.bootstrap.Bootstrap; import io.netty.buffer.Unpooled; import io.netty.channel.Channel; import io.netty.channel.ChannelInitializer; import io.netty.channel.ChannelPipeline; import io.netty.channel.EventLoopGroup; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.SocketChannel; import io.netty.channel.socket.nio.NioSocketChannel; import io.netty.handler.codec.http.DefaultHttpHeaders; import io.netty.handler.codec.http.HttpClientCodec; import io.netty.handler.codec.http.HttpObjectAggregator; import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame; import io.netty.handler.codec.http.websocketx.CloseWebSocketFrame; import io.netty.handler.codec.http.websocketx.PingWebSocketFrame; import io.netty.handler.codec.http.websocketx.TextWebSocketFrame; import io.netty.handler.codec.http.websocketx.WebSocketClientHandshakerFactory; import io.netty.handler.codec.http.websocketx.WebSocketVersion; import io.netty.handler.codec.http.websocketx.extensions.compression.WebSocketClientCompressionHandler; import io.netty.handler.ssl.SslContext; import io.netty.handler.ssl.SslContextBuilder; import io.netty.handler.ssl.util.InsecureTrustManagerFactory; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.net.URI; import java.net.URISyntaxException; import java.nio.ByteBuffer; import javax.net.ssl.SSLException; /** * WebSocket client class for test */ public class WebSocketClient { private static final Logger log = LoggerFactory.getLogger(WebSocketClient.class); private final String url; private Channel channel = null; private WebSocketClientHandler handler; EventLoopGroup group; /** * @param url the URL which the client should connect. */ public WebSocketClient(String url) { this.url = System.getProperty("url", url); } /** * Do the handshake for the given url and return the state of the handshake. * * @return true if the handshake is done properly. * @throws URISyntaxException throws if there is an error in the URI syntax. * @throws InterruptedException throws if the connecting the server is interrupted. */ public boolean handhshake() throws InterruptedException, URISyntaxException, SSLException { boolean isDone; URI uri = new URI(url); String scheme = uri.getScheme() == null ? "ws" : uri.getScheme(); final String host = uri.getHost() == null ? "127.0.0.1" : uri.getHost(); final int port; if (uri.getPort() == -1) { if ("ws".equalsIgnoreCase(scheme)) { port = 80; } else if ("wss".equalsIgnoreCase(scheme)) { port = 443; } else { port = -1; } } else { port = uri.getPort(); } if (!"ws".equalsIgnoreCase(scheme) && !"wss".equalsIgnoreCase(scheme)) { log.error("Only WS and WSS protocols are supported."); return false; } final boolean ssl = "wss".equalsIgnoreCase(scheme); final SslContext sslCtx; if (ssl) { sslCtx = SslContextBuilder.forClient().trustManager(InsecureTrustManagerFactory.INSTANCE).build(); } else { sslCtx = null; } group = new NioEventLoopGroup(); try { // Connect with V13 (RFC 6455 aka HyBi-17). You can change it to V08 or V00. // If you change it to V00, ping is not supported and remember to change // HttpResponseDecoder to WebSocketHttpResponseDecoder in the pipeline. handler = new WebSocketClientHandler(WebSocketClientHandshakerFactory.newHandshaker(uri, WebSocketVersion.V13, null, true, new DefaultHttpHeaders())); Bootstrap b = new Bootstrap(); b.group(group).channel(NioSocketChannel.class).handler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) { ChannelPipeline p = ch.pipeline(); if (sslCtx != null) { p.addLast(sslCtx.newHandler(ch.alloc(), host, port)); } p.addLast(new HttpClientCodec(), new HttpObjectAggregator(8192), WebSocketClientCompressionHandler.INSTANCE, handler); } }); channel = b.connect(uri.getHost(), port).sync().channel(); isDone = handler.handshakeFuture().sync().isSuccess(); } catch (Exception e) { log.error("Handshake unsuccessful: " + e.getMessage(), e); return false; } log.info("WebSocket Handshake successful: " + isDone); return isDone; } /** * Send text to the server. * * @param text text need to be sent. */ public void sendText(String text) { if (channel == null) { log.error("Channel is null, cannot write data."); throw new NullPointerException("Cannot find the channel to write"); } channel.writeAndFlush(new TextWebSocketFrame(text)); } /** * Send binary data to server. * * @param buf buffer containing the data need to be sent. */ public void sendBinary(ByteBuffer buf) { if (channel == null) { log.error("Channel is null, cannot write data."); throw new NullPointerException("Cannot find the channel to write"); } channel.writeAndFlush(new BinaryWebSocketFrame(Unpooled.wrappedBuffer(buf))); } /** * Send a pong message to the server. * * @param buf content of the pong message to be sent. */ public void sendPing(ByteBuffer buf) { if (channel == null) { log.error("Channel is null, cannot write data."); throw new NullPointerException("Cannot find the channel to write"); } channel.writeAndFlush(new PingWebSocketFrame(Unpooled.wrappedBuffer(buf))); } /** * Extract the text data received from the server. * * @return the text received from the server. */ public String getTextReceived() { return handler.getTextReceived(); } /** * Extract the binary data received from the server. * * @return the binary data received from the server. */ public ByteBuffer getBufferReceived() { return handler.getBufferReceived(); } /** * Shutdown the WebSocket Client. * * @throws InterruptedException throws if interruption happened when closing the connection. */ public void shutDown() throws InterruptedException { channel.writeAndFlush(new CloseWebSocketFrame()); channel.closeFuture().sync(); group.shutdownGracefully(); } }