本篇内容介绍了“RocketMQTemplate的原理和作用是什么”的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！
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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 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 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 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 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> 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 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);
}
}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);
}
}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 UDP, this method won't wait for
* acknowledgement from broker before return. Obviously, it has maximums throughput yet potentials of message loss.
*
* 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);
}
}
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);
}
}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);
}
}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
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