BlinkTrade.java

package blinktrade;

import java.net.URI;

import java.util.Arrays;
import java.util.stream.Collectors;
import java.lang.reflect.Field;
import java.lang.Math;

import org.java_websocket.WebSocketImpl;
import org.java_websocket.client.WebSocketClient;
import org.java_websocket.handshake.ServerHandshake;

public class BlinkTrade {
    private static final String ENDPOINT = "ws://bitcambio_api.blinktrade.com/trade/";
    private static final String HOST = "bitcambio_api.blinktrade.com";

    private WebSocketClient client;

    public void heartbeat() {
        long date = System.currentTimeMillis() / 1000L;
        String msg = String.format("{\"MsgType\": \"1\", \"TestReqID\": %d, \"SendTime\": %d}", date, date);
        client.send(msg);
    }

    public void subscribeTicker(String[] data) {
        int reqId = (int) (Math.random() * 1e7);

        String instruments = Arrays
            .stream(data)
            .map(x -> "\"" + x + "\"")
            .collect(Collectors.joining(","));

        String msg = String.format(
            "{\"MsgType\": \"e\", \"SecurityStatusReqID\": %d, \"SubscriptionRequestType\": \"1\", \"Instruments\": [%s]}",
            reqId,
            instruments
        );
        client.send(msg);
    }

    // Reflection hack to supports endpoints with underscores
    public static URI getURI(String url, String host) throws Exception {
        URI uri = new URI(BlinkTrade.ENDPOINT);
        if (uri.getHost() == null) {
            final Field hostField = URI.class.getDeclaredField("host");
            hostField.setAccessible(true);
            hostField.set(uri, host);
        }

        return uri;
    }

    public static void main(String[] args) throws Exception {
        BlinkTrade blinktrade = new BlinkTrade();

        URI uri = BlinkTrade.getURI(BlinkTrade.ENDPOINT, BlinkTrade.HOST);
        blinktrade.client = new WebSocketClient(uri) {

            @Override
            public void onOpen(ServerHandshake handshake) {
                System.out.println("Opened");
            }

            @Override
            public void onClose(int code, String reason, boolean remote) {
                System.out.println("Closed: " + code + " : " + reason);
            }

            @Override
            public void onError(Exception ex) {
                System.out.println("Error");
                ex.printStackTrace(System.out);
            }

            @Override
            public void onMessage(String message) {
                if (message.indexOf("\"f\"") != -1) {
                    System.out.println(message);
                }
            }
        };

        // Connect!
        blinktrade.client.connectBlocking();

        blinktrade.heartbeat();
        blinktrade.subscribeTicker(new String[] { "BLINK:BTCBRL", "UOL:USDBRT", "UOL:USDBRL" });
    }
}