jnidzwetzki/bitfinex-v2-wss-api-java

/*******************************************************************************
 *
 *    Copyright (C) 2015-2018 Jan Kristof Nidzwetzki
 *  
 *    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 com.github.jnidzwetzki.bitfinex.v2;

import java.io.Closeable;
import java.io.IOException;
import java.net.URI;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.function.Consumer;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Throwables;

import jakarta.websocket.ClientEndpoint;
import jakarta.websocket.CloseReason;
import jakarta.websocket.CloseReason.CloseCodes;
import jakarta.websocket.ContainerProvider;
import jakarta.websocket.DeploymentException;
import jakarta.websocket.OnClose;
import jakarta.websocket.OnError;
import jakarta.websocket.OnMessage;
import jakarta.websocket.OnOpen;
import jakarta.websocket.Session;
import jakarta.websocket.WebSocketContainer;

@ClientEndpoint
public class WebsocketClientEndpoint implements Closeable {

    /**
     * The user session
     */
    private Session userSession = null;

    /**
     * The message consumer
     */
    private final Consumer<String> onMessageConsumer;

    /**
     * The error consumer
     */
    private final Consumer<Throwable> onErrorConsumer;

    /**
     * The close reason consumer
     */
    private final Consumer<CloseReason> onCloseConsumer;
    /**
     * The endpoint URL
     */
    private final URI endpointURI;
    
    /**
     * The Logger
     */
    private final static Logger logger = LoggerFactory.getLogger(SimpleBitfinexApiBroker.class);

    /**
     * The wait for connection latch
     */
    private CountDownLatch connectLatch = new CountDownLatch(0);

    public WebsocketClientEndpoint(URI bitfinexURI, Consumer<String> onMessageConsumer,
                                   Consumer<CloseReason> onCloseConsumer,
                                   Consumer<Throwable> onErrorConsumer) {
        this.endpointURI = bitfinexURI;
        this.onMessageConsumer = onMessageConsumer;
        this.onCloseConsumer = onCloseConsumer;
        this.onErrorConsumer = onErrorConsumer;
    }

    /**
     * Open a new connection and wait until connection is ready
     * 
     * @throws DeploymentException
     * @throws IOException
     * @throws InterruptedException
     */
    public void connect() throws DeploymentException, IOException, InterruptedException {
        final WebSocketContainer container = ContainerProvider.getWebSocketContainer();
        connectLatch = new CountDownLatch(1);
        this.userSession = container.connectToServer(this, endpointURI);
        connectLatch.await(15, TimeUnit.SECONDS);
    }

    @OnOpen
    public void onOpen(final Session userSession) {
        logger.debug("Websocket is now open");
        connectLatch.countDown();
    }

    @OnClose
    public void onClose(final Session userSession, final CloseReason reason) {
        logger.debug("Closing websocket: {}", reason);
        onCloseConsumer.accept(reason);
        this.userSession = null;
    }

    @OnMessage(maxMessageSize=1048576)
    public void onMessage(final String message) {
        onMessageConsumer.accept(message);
    }
    
    @OnError
    public void onError(final Session session, final Throwable t) {
        logger.error("OnError called {}", Throwables.getStackTraceAsString(t));
        onErrorConsumer.accept(t);
        connectLatch.countDown();
    }

    /**
     * Send a new message to the server
     * @param message
     */
    public void sendMessage(final String message) {
        if(userSession == null) {
            logger.error("Unable to send message, user session is null");
            return;
        }
        if(userSession.getAsyncRemote() == null) {
            logger.error("Unable to send message, async remote is null");
            return;
        }
        userSession.getAsyncRemote().sendText(message);
    }

    /**
     * Close the connection
     */
    @Override
    public void close() {
        if(userSession == null) {
            return;
        }
        
        try {
            final CloseReason closeReason = new CloseReason(CloseCodes.NORMAL_CLOSURE, "Socket closed");
            userSession.close(closeReason);
        } catch (Throwable e) {
            logger.error("Got exception while closing socket", e);
        }
        
        userSession = null;
    }
    
    /**
     * Is this websocket connected
     * @return
     */
    public boolean isConnected() {
        return userSession != null;
    }
}