聊聊RocketMQTemplate

序

本文主要研究一下RocketMQTemplate

RocketMQTemplate

rocketmq-spring-boot-2.0.3-sources.jar!/org/apache/rocketmq/spring/core/RocketMQTemplate.java

public class RocketMQTemplate extends AbstractMessageSendingTemplate<String> implements InitializingBean, DisposableBean {
    private static final  Logger log = LoggerFactory.getLogger(RocketMQTemplate.class);

    private DefaultMQProducer producer;

    private ObjectMapper objectMapper;

    private String charset = "UTF-8";

    private MessageQueueSelector messageQueueSelector = new SelectMessageQueueByHash();

    private final Map<String, TransactionMQProducer> cache = new ConcurrentHashMap<>(); //only put TransactionMQProducer by now!!!

    //......

    @Override
    public void afterPropertiesSet() throws Exception {
        if (producer != null) {
            producer.start();
        }
    }

    @Override
    protected void doSend(String destination, Message<?> message) {
        SendResult sendResult = syncSend(destination, message);
        log.debug("send message to `{}` finished. result:{}", destination, sendResult);
    }



    @Override
    protected Message<?> doConvert(Object payload, Map<String, Object> headers, MessagePostProcessor postProcessor) {
        String content;
        if (payload instanceof String) {
            content = (String) payload;
        } else {
            // If payload not as string, use objectMapper change it.
            try {
                content = objectMapper.writeValueAsString(payload);
            } catch (JsonProcessingException e) {
                log.error("convert payload to String failed. payload:{}", payload);
                throw new RuntimeException("convert to payload to String failed.", e);
            }
        }

        MessageBuilder<?> builder = MessageBuilder.withPayload(content);
        if (headers != null) {
            builder.copyHeaders(headers);
        }
        builder.setHeaderIfAbsent(MessageHeaders.CONTENT_TYPE, MimeTypeUtils.TEXT_PLAIN);

        Message<?> message = builder.build();
        if (postProcessor != null) {
            message = postProcessor.postProcessMessage(message);
        }
        return message;
    }

    @Override
    public void destroy() {
        if (Objects.nonNull(producer)) {
            producer.shutdown();
        }

        for (Map.Entry<String, TransactionMQProducer> kv : cache.entrySet()) {
            if (Objects.nonNull(kv.getValue())) {
                kv.getValue().shutdown();
            }
        }
        cache.clear();
    }

    //......
}

• RocketMQTemplate继承了spring-messaging的AbstractMessageSendingTemplate，实现了InitializingBean, DisposableBean接口；提供了syncSend、syncSendOrderly、asyncSend、asyncSendOrderly、sendOneWay、sendOneWayOrderly、sendMessageInTransaction等方法
• afterPropertiesSet方法执行producer.start()；destroy方法执行producer.shutdown()以及TransactionMQProducer的shutdown并清空cache集合
• doSend方法内部调用的是syncSend方法，返回的sendResult仅仅debug输出；doConvert方法针对String类型的payload不做处理，其他类型使用objectMapper.writeValueAsString转为String作为content，然后构造message，执行postProcessor.postProcessMessage，然后返回

syncSend

rocketmq-spring-boot-2.0.3-sources.jar!/org/apache/rocketmq/spring/core/RocketMQTemplate.java

    /**
     * Same to {@link #syncSend(String, Message)} with send timeout specified in addition.
     *
     * @param destination formats: `topicName:tags`
     * @param message     {@link org.springframework.messaging.Message}
     * @param timeout     send timeout with millis
     * @param delayLevel  level for the delay message
     * @return {@link SendResult}
     */
    public SendResult syncSend(String destination, Message<?> message, long timeout, int delayLevel) {
        if (Objects.isNull(message) || Objects.isNull(message.getPayload())) {
            log.error("syncSend failed. destination:{}, message is null ", destination);
            throw new IllegalArgumentException("`message` and `message.payload` cannot be null");
        }

        try {
            long now = System.currentTimeMillis();
            org.apache.rocketmq.common.message.Message rocketMsg = RocketMQUtil.convertToRocketMessage(objectMapper,
                charset, destination, message);
            if (delayLevel > 0) {
                rocketMsg.setDelayTimeLevel(delayLevel);
            }
            SendResult sendResult = producer.send(rocketMsg, timeout);
            long costTime = System.currentTimeMillis() - now;
            log.debug("send message cost: {} ms, msgId:{}", costTime, sendResult.getMsgId());
            return sendResult;
        } catch (Exception e) {
            log.error("syncSend failed. destination:{}, message:{} ", destination, message);
            throw new MessagingException(e.getMessage(), e);
        }
    }

    /**
     * syncSend batch messages in a given timeout.
     *
     * @param destination formats: `topicName:tags`
     * @param messages    Collection of {@link org.springframework.messaging.Message}
     * @param timeout     send timeout with millis
     * @return {@link SendResult}
     */
    public SendResult syncSend(String destination, Collection<Message<?>> messages, long timeout) {
        if (Objects.isNull(messages) || messages.size() == 0) {
            log.error("syncSend with batch failed. destination:{}, messages is empty ", destination);
            throw new IllegalArgumentException("`messages` can not be empty");
        }

        try {
            long now = System.currentTimeMillis();
            Collection<org.apache.rocketmq.common.message.Message> rmqMsgs = new ArrayList<>();
            org.apache.rocketmq.common.message.Message rocketMsg;
            for (Message<?> msg:messages) {
                if (Objects.isNull(msg) || Objects.isNull(msg.getPayload())) {
                    log.warn("Found a message empty in the batch, skip it");
                    continue;
                }
                rocketMsg = RocketMQUtil.convertToRocketMessage(objectMapper, charset, destination, msg);
                rmqMsgs.add(rocketMsg);
            }

            SendResult sendResult = producer.send(rmqMsgs, timeout);
            long costTime = System.currentTimeMillis() - now;
            log.debug("send messages cost: {} ms, msgId:{}", costTime, sendResult.getMsgId());
            return sendResult;
        } catch (Exception e) {
            log.error("syncSend with batch failed. destination:{}, messages.size:{} ", destination, messages.size());
            throw new MessagingException(e.getMessage(), e);
        }
    }

• syncSend方法支持单个及多个org.springframework.messaging.Message，其中单个Message的接口支持delayLevel

syncSendOrderly

rocketmq-spring-boot-2.0.3-sources.jar!/org/apache/rocketmq/spring/core/RocketMQTemplate.java

    /**
     * Same to {@link #syncSendOrderly(String, Message, String)} with send timeout specified in addition.
     *
     * @param destination formats: `topicName:tags`
     * @param message     {@link org.springframework.messaging.Message}
     * @param hashKey     use this key to select queue. for example: orderId, productId ...
     * @param timeout     send timeout with millis
     * @return {@link SendResult}
     */
    public SendResult syncSendOrderly(String destination, Message<?> message, String hashKey, long timeout) {
        if (Objects.isNull(message) || Objects.isNull(message.getPayload())) {
            log.error("syncSendOrderly failed. destination:{}, message is null ", destination);
            throw new IllegalArgumentException("`message` and `message.payload` cannot be null");
        }

        try {
            long now = System.currentTimeMillis();
            org.apache.rocketmq.common.message.Message rocketMsg = RocketMQUtil.convertToRocketMessage(objectMapper,
                charset, destination, message);
            SendResult sendResult = producer.send(rocketMsg, messageQueueSelector, hashKey, timeout);
            long costTime = System.currentTimeMillis() - now;
            log.debug("send message cost: {} ms, msgId:{}", costTime, sendResult.getMsgId());
            return sendResult;
        } catch (Exception e) {
            log.error("syncSendOrderly failed. destination:{}, message:{} ", destination, message);
            throw new MessagingException(e.getMessage(), e);
        }
    }

• syncSendOrderly方法内部调用的是producer.send(rocketMsg, messageQueueSelector, hashKey, timeout)方法，同步返回SendResult

asyncSend

rocketmq-spring-boot-2.0.3-sources.jar!/org/apache/rocketmq/spring/core/RocketMQTemplate.java

    /**
     * Same to {@link #asyncSend(String, Message, SendCallback)} with send timeout and delay level specified in addition.
     *
     * @param destination  formats: `topicName:tags`
     * @param message      {@link org.springframework.messaging.Message}
     * @param sendCallback {@link SendCallback}
     * @param timeout      send timeout with millis
     * @param delayLevel   level for the delay message
     */
    public void asyncSend(String destination, Message<?> message, SendCallback sendCallback, long timeout, int delayLevel) {
        if (Objects.isNull(message) || Objects.isNull(message.getPayload())) {
            log.error("asyncSend failed. destination:{}, message is null ", destination);
            throw new IllegalArgumentException("`message` and `message.payload` cannot be null");
        }

        try {
            org.apache.rocketmq.common.message.Message rocketMsg = RocketMQUtil.convertToRocketMessage(objectMapper,
                charset, destination, message);
            if (delayLevel > 0) {
                rocketMsg.setDelayTimeLevel(delayLevel);
            }
            producer.send(rocketMsg, sendCallback, timeout);
        } catch (Exception e) {
            log.info("asyncSend failed. destination:{}, message:{} ", destination, message);
            throw new MessagingException(e.getMessage(), e);
        }
    }

• asyncSend方法需要传入SendCallback，内部执行的是producer.send(rocketMsg, sendCallback, timeout)

asyncSendOrderly

rocketmq-spring-boot-2.0.3-sources.jar!/org/apache/rocketmq/spring/core/RocketMQTemplate.java

    /**
     * Same to {@link #asyncSendOrderly(String, Message, String, SendCallback)} with send timeout specified in
     * addition.
     *
     * @param destination  formats: `topicName:tags`
     * @param message      {@link org.springframework.messaging.Message}
     * @param hashKey      use this key to select queue. for example: orderId, productId ...
     * @param sendCallback {@link SendCallback}
     * @param timeout      send timeout with millis
     */
    public void asyncSendOrderly(String destination, Message<?> message, String hashKey, SendCallback sendCallback,
                                 long timeout) {
        if (Objects.isNull(message) || Objects.isNull(message.getPayload())) {
            log.error("asyncSendOrderly failed. destination:{}, message is null ", destination);
            throw new IllegalArgumentException("`message` and `message.payload` cannot be null");
        }

        try {
            org.apache.rocketmq.common.message.Message rocketMsg = RocketMQUtil.convertToRocketMessage(objectMapper,
                charset, destination, message);
            producer.send(rocketMsg, messageQueueSelector, hashKey, sendCallback, timeout);
        } catch (Exception e) {
            log.error("asyncSendOrderly failed. destination:{}, message:{} ", destination, message);
            throw new MessagingException(e.getMessage(), e);
        }
    }

• asyncSendOrderly方法内部执行的是producer.send(rocketMsg, messageQueueSelector, hashKey, sendCallback, timeout)

sendOneWay

rocketmq-spring-boot-2.0.3-sources.jar!/org/apache/rocketmq/spring/core/RocketMQTemplate.java

    /**
     * Similar to <a href="https://en.wikipedia.org/wiki/User_Datagram_Protocol">UDP</a>, this method won't wait for
     * acknowledgement from broker before return. Obviously, it has maximums throughput yet potentials of message loss.
     * <p>
     * One-way transmission is used for cases requiring moderate reliability, such as log collection.
     *
     * @param destination formats: `topicName:tags`
     * @param message     {@link org.springframework.messaging.Message}
     */
    public void sendOneWay(String destination, Message<?> message) {
        if (Objects.isNull(message) || Objects.isNull(message.getPayload())) {
            log.error("sendOneWay failed. destination:{}, message is null ", destination);
            throw new IllegalArgumentException("`message` and `message.payload` cannot be null");
        }

        try {
            org.apache.rocketmq.common.message.Message rocketMsg = RocketMQUtil.convertToRocketMessage(objectMapper,
                charset, destination, message);
            producer.sendOneway(rocketMsg);
        } catch (Exception e) {
            log.error("sendOneWay failed. destination:{}, message:{} ", destination, message);
            throw new MessagingException(e.getMessage(), e);
        }
    }

• sendOneWay方法内部执行的是producer.sendOneway(rocketMsg)

sendOneWayOrderly

rocketmq-spring-boot-2.0.3-sources.jar!/org/apache/rocketmq/spring/core/RocketMQTemplate.java

    /**
     * Same to {@link #sendOneWay(String, Message)} with send orderly with hashKey by specified.
     *
     * @param destination formats: `topicName:tags`
     * @param message     {@link org.springframework.messaging.Message}
     * @param hashKey     use this key to select queue. for example: orderId, productId ...
     */
    public void sendOneWayOrderly(String destination, Message<?> message, String hashKey) {
        if (Objects.isNull(message) || Objects.isNull(message.getPayload())) {
            log.error("sendOneWayOrderly failed. destination:{}, message is null ", destination);
            throw new IllegalArgumentException("`message` and `message.payload` cannot be null");
        }

        try {
            org.apache.rocketmq.common.message.Message rocketMsg = RocketMQUtil.convertToRocketMessage(objectMapper,
                charset, destination, message);
            producer.sendOneway(rocketMsg, messageQueueSelector, hashKey);
        } catch (Exception e) {
            log.error("sendOneWayOrderly failed. destination:{}, message:{}", destination, message);
            throw new MessagingException(e.getMessage(), e);
        }
    }

• sendOneWayOrderly方法内部执行的是producer.sendOneway(rocketMsg, messageQueueSelector, hashKey)

sendMessageInTransaction

rocketmq-spring-boot-2.0.3-sources.jar!/org/apache/rocketmq/spring/core/RocketMQTemplate.java

    /**
     * Send Spring Message in Transaction
     *
     * @param txProducerGroup the validate txProducerGroup name, set null if using the default name
     * @param destination     destination formats: `topicName:tags`
     * @param message         message {@link org.springframework.messaging.Message}
     * @param arg             ext arg
     * @return TransactionSendResult
     * @throws MessagingException
     */
    public TransactionSendResult sendMessageInTransaction(final String txProducerGroup, final String destination, final Message<?> message, final Object arg) throws MessagingException {
        try {
            TransactionMQProducer txProducer = this.stageMQProducer(txProducerGroup);
            org.apache.rocketmq.common.message.Message rocketMsg = RocketMQUtil.convertToRocketMessage(objectMapper,
                charset, destination, message);
            return txProducer.sendMessageInTransaction(rocketMsg, arg);
        } catch (MQClientException e) {
            throw RocketMQUtil.convert(e);
        }
    }

• sendMessageInTransaction方法内部执行的是txProducer.sendMessageInTransaction(rocketMsg, arg)

小结

• RocketMQTemplate继承了spring-messaging的AbstractMessageSendingTemplate，实现了InitializingBean, DisposableBean接口；提供了syncSend、syncSendOrderly、asyncSend、asyncSendOrderly、sendOneWay、sendOneWayOrderly、sendMessageInTransaction等方法
• afterPropertiesSet方法执行producer.start()；destroy方法执行producer.shutdown()以及TransactionMQProducer的shutdown并清空cache集合
• doSend方法内部调用的是syncSend方法，返回的sendResult仅仅debug输出；doConvert方法针对String类型的payload不做处理，其他类型使用objectMapper.writeValueAsString转为String作为content，然后构造message，执行postProcessor.postProcessMessage，然后返回

doc

• RocketMQTemplate