Method main

java/examples/src/main/java/examples/CompareExchanges.java:17–55

(String[] args)

public class CompareExchanges {

    @SuppressWarnings("unchecked")
    public static void main(String[] args) {
        String symbol = args.length > 0 ? args[0] : "BTC/USDT";
        String[] exchangeIds = {"binance", "bybit", "okx", "kraken", "bitget"};

        System.out.println("Comparing " + symbol + " across exchanges\n");

        System.out.printf("%-12s %12s %12s %12s %10s%n",
                "Exchange", "Last", "Bid", "Ask", "Spread");
        System.out.println("-".repeat(60));

        for (String id : exchangeIds) {
            try {
                Exchange exchange = Exchange.dynamicallyCreateInstance(id, null);
                exchange.loadMarkets(false).join();

                // Untyped: fetchTicker returns CompletableFuture<Object>
                Map<String, Object> ticker = (Map<String, Object>) exchange.fetchTicker(symbol).join();

                Double last = toDouble(ticker.get("last"));
                Double bid = toDouble(ticker.get("bid"));
                Double ask = toDouble(ticker.get("ask"));

                double spread = 0;
                if (ask != null && bid != null) {
                    spread = ask - bid;
                }

                System.out.printf("%-12s %12.2f %12.2f %12.2f %10.2f%n",
                        id,
                        safe(last),
                        safe(bid),
                        safe(ask),
                        spread);
            } catch (Exception e) {
                System.out.printf("%-12s %s%n", id, "ERROR: " + rootMessage(e));
            }
        }
    }

    static Double toDouble(Object v) {
        if (v instanceof Number n) return n.doubleValue();