io.ballerina.plugins.idea.debugger.client.WebSocketClient.java Source code

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Here is the source code for io.ballerina.plugins.idea.debugger.client.WebSocketClient.java

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/*
 * Copyright (c) 2018, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * Licensed 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 io.ballerina.plugins.idea.debugger.client;

import io.ballerina.plugins.idea.debugger.Callback;
import io.netty.bootstrap.Bootstrap;
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.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.util.HashMap;
import java.util.Map;

import javax.net.ssl.SSLException;

/**
 * WebSocket client which is used to connect to debug server.
 */
public class WebSocketClient {

    private static final Logger LOGGER = LoggerFactory.getLogger(WebSocketClient.class);

    private Channel channel = null;
    private WebSocketClientHandler handler;
    private final Map<String, String> headers;
    private final String url;
    private final EventLoopGroup group = new NioEventLoopGroup();

    public WebSocketClient(String url) {
        this.url = url;
        this.headers = new HashMap<>();
    }

    /**
     * @param callback callback which should be called when a response is received.
     * @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 handshake(Callback callback) 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)) {
            LOGGER.debug("Only WS(S) is supported.");
            return false;
        }

        final boolean ssl = "wss".equalsIgnoreCase(scheme);
        final SslContext sslCtx;
        if (ssl) {
            sslCtx = SslContextBuilder.forClient().trustManager(InsecureTrustManagerFactory.INSTANCE).build();
        } else {
            sslCtx = null;
        }

        DefaultHttpHeaders httpHeaders = new DefaultHttpHeaders();
        headers.forEach(httpHeaders::add);
        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, httpHeaders), callback);

            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) {
            LOGGER.debug("Handshake unsuccessful : " + e.getMessage(), e);
            group.shutdownGracefully();
            return false;
        }
        LOGGER.debug("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) {
            LOGGER.debug("Channel is null. Cannot send text.");
            throw new IllegalArgumentException("Cannot find the channel to write");
        }
        channel.writeAndFlush(new TextWebSocketFrame(text));
    }

    public boolean isConnected() {
        return handler.isConnected();
    }

    /**
     * Shutdown the WebSocket Client.
     */
    public void shutDown() throws InterruptedException {
        group.shutdownGracefully();
    }
}