ApsaraMQ for RocketMQ:Send normal messages in synchronous, asynchronous, or one-way mode

Message msg = new Message(
    "TopicTestMQ",          // Topic -- must be a normal-message topic
    "TagA",                 // Tag -- used by consumers to filter messages
    "Hello MQ".getBytes()   // Body -- binary payload; producer and consumer must
                            // agree on the serialization format
);

// Optional: set a business key for message tracing in the console.
msg.setKey("ORDERID_100");

for (int i = 0; i < 100; i++) {
    Message msg = new Message("TopicTestMQ", "TagA", "Hello MQ".getBytes());
    msg.setKey("ORDERID_" + i);

    try {
        SendResult sendResult = producer.send(msg);
        // A non-null result means the broker accepted the message.
        if (sendResult != null) {
            System.out.println(new Date() + " Send mq message success. Topic is:"
                + msg.getTopic() + " msgId is: " + sendResult.getMessageId());
        }
    } catch (Exception e) {
        // Handle failures: retry or persist the message for later delivery.
        System.out.println(new Date() + " Send mq message failed. Topic is:" + msg.getTopic());
        e.printStackTrace();
    }
}

Message msg = new Message("TopicTestMQ", "TagA", "Hello MQ".getBytes());
msg.setKey("ORDERID_100");

producer.sendAsync(msg, new SendCallback() {
    @Override
    public void onSuccess(final SendResult sendResult) {
        System.out.println("send message success. topic=" + sendResult.getTopic()
            + ", msgId=" + sendResult.getMessageId());
    }

    @Override
    public void onException(OnExceptionContext context) {
        // Handle failures: retry or persist the message for later delivery.
        System.out.println("send message failed. topic=" + context.getTopic()
            + ", msgId=" + context.getMessageId());
    }
});

// Block for 3 seconds to wait for the callback. In production, use a
// CountDownLatch or similar mechanism instead of Thread.sleep.
TimeUnit.SECONDS.sleep(3);

for (int i = 0; i < 100; i++) {
    Message msg = new Message("TopicTestMQ", "TagA", "Hello MQ".getBytes());
    msg.setKey("ORDERID_" + i);

    // No return value, no callback. Fire and forget.
    producer.sendOneway(msg);
}