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本文主要研究一下rocketmq的ProducerImpl
ProducerImpl
io/openmessaging/rocketmq/producer/ProducerImpl.java
public class ProducerImpl extends AbstractOMSProducer implements Producer {
public ProducerImpl(final KeyValue properties) {
super(properties);
}
@Override
public KeyValue properties() {
return properties;
}
@Override
public SendResult send(final Message message) {
return send(message, this.rocketmqProducer.getSendMsgTimeout());
}
@Override
public SendResult send(final Message message, final KeyValue properties) {
long timeout = properties.containsKey(PropertyKeys.OPERATION_TIMEOUT)
? properties.getInt(PropertyKeys.OPERATION_TIMEOUT) : this.rocketmqProducer.getSendMsgTimeout();
return send(message, timeout);
}
private SendResult send(final Message message, long timeout) {
checkMessageType(message);
org.apache.rocketmq.common.message.Message rmqMessage = msgConvert((BytesMessage) message);
try {
org.apache.rocketmq.client.producer.SendResult rmqResult = this.rocketmqProducer.send(rmqMessage, timeout);
if (!rmqResult.getSendStatus().equals(SendStatus.SEND_OK)) {
log.error(String.format("Send message to RocketMQ failed, %s", message));
throw new OMSRuntimeException("-1", "Send message to RocketMQ broker failed.");
}
message.headers().put(MessageHeader.MESSAGE_ID, rmqResult.getMsgId());
return OMSUtil.sendResultConvert(rmqResult);
} catch (Exception e) {
log.error(String.format("Send message to RocketMQ failed, %s", message), e);
throw checkProducerException(rmqMessage.getTopic(), message.headers().getString(MessageHeader.MESSAGE_ID), e);
}
}
@Override
public Promise<SendResult> sendAsync(final Message message) {
return sendAsync(message, this.rocketmqProducer.getSendMsgTimeout());
}
@Override
public Promise<SendResult> sendAsync(final Message message, final KeyValue properties) {
long timeout = properties.containsKey(PropertyKeys.OPERATION_TIMEOUT)
? properties.getInt(PropertyKeys.OPERATION_TIMEOUT) : this.rocketmqProducer.getSendMsgTimeout();
return sendAsync(message, timeout);
}
private Promise<SendResult> sendAsync(final Message message, long timeout) {
checkMessageType(message);
org.apache.rocketmq.common.message.Message rmqMessage = msgConvert((BytesMessage) message);
final Promise<SendResult> promise = new DefaultPromise<>();
try {
this.rocketmqProducer.send(rmqMessage, new SendCallback() {
@Override
public void onSuccess(final org.apache.rocketmq.client.producer.SendResult rmqResult) {
message.headers().put(MessageHeader.MESSAGE_ID, rmqResult.getMsgId());
promise.set(OMSUtil.sendResultConvert(rmqResult));
}
@Override
public void onException(final Throwable e) {
promise.setFailure(e);
}
}, timeout);
} catch (Exception e) {
promise.setFailure(e);
}
return promise;
}
@Override
public void sendOneway(final Message message) {
checkMessageType(message);
org.apache.rocketmq.common.message.Message rmqMessage = msgConvert((BytesMessage) message);
try {
this.rocketmqProducer.sendOneway(rmqMessage);
} catch (Exception ignore) { //Ignore the oneway exception.
}
}
@Override
public void sendOneway(final Message message, final KeyValue properties) {
sendOneway(message);
}
}
- 发送消息的方法主要是代理给rocketmqProducer
- 另外调用OMSUtil.msgConvert将api的BytesMessage转换为org.apache.rocketmq.common.message.Message
- 对于异步采用的是DefaultPromise,其callback为SendCallback
OMSUtil.msgConvert
io/openmessaging/rocketmq/utils/OMSUtil.java
public static org.apache.rocketmq.common.message.Message msgConvert(BytesMessage omsMessage) {
org.apache.rocketmq.common.message.Message rmqMessage = new org.apache.rocketmq.common.message.Message();
rmqMessage.setBody(omsMessage.getBody());
KeyValue headers = omsMessage.headers();
KeyValue properties = omsMessage.properties();
//All destinations in RocketMQ use Topic
if (headers.containsKey(MessageHeader.TOPIC)) {
rmqMessage.setTopic(headers.getString(MessageHeader.TOPIC));
rmqMessage.putUserProperty(NonStandardKeys.MESSAGE_DESTINATION, "TOPIC");
} else {
rmqMessage.setTopic(headers.getString(MessageHeader.QUEUE));
rmqMessage.putUserProperty(NonStandardKeys.MESSAGE_DESTINATION, "QUEUE");
}
for (String key : properties.keySet()) {
MessageAccessor.putProperty(rmqMessage, key, properties.getString(key));
}
//Headers has a high priority
for (String key : headers.keySet()) {
MessageAccessor.putProperty(rmqMessage, key, headers.getString(key));
}
return rmqMessage;
}
- 这里主要是转换header及topic信息
SendCallback
org/apache/rocketmq/client/producer/SendCallback.java
public interface SendCallback {
void onSuccess(final SendResult sendResult);
void onException(final Throwable e);
}
- 对于成功,将SendResult传递过来,对于异常则传递Throwable
DefaultPromise
io/openmessaging/rocketmq/promise/DefaultPromise.java
public class DefaultPromise<V> implements Promise<V> {
private static final Logger LOG = LoggerFactory.getLogger(DefaultPromise.class);
private final Object lock = new Object();
private volatile FutureState state = FutureState.DOING;
private V result = null;
private long timeout;
private long createTime;
private Throwable exception = null;
private List<PromiseListener<V>> promiseListenerList;
public DefaultPromise() {
createTime = System.currentTimeMillis();
promiseListenerList = new ArrayList<>();
timeout = 5000;
}
//......
@Override
public boolean set(final V value) {
if (value == null)
return false;
this.result = value;
return done();
}
@Override
public boolean setFailure(final Throwable cause) {
if (cause == null)
return false;
this.exception = cause;
return done();
}
private boolean done() {
synchronized (lock) {
if (!isDoing()) {
return false;
}
state = FutureState.DONE;
lock.notifyAll();
}
notifyListeners();
return true;
}
private void notifyListeners() {
if (promiseListenerList != null) {
for (PromiseListener<V> listener : promiseListenerList) {
notifyListener(listener);
}
}
}
private void notifyListener(final PromiseListener<V> listener) {
try {
if (exception != null)
listener.operationFailed(this);
else
listener.operationCompleted(this);
} catch (Throwable t) {
LOG.error("notifyListener {} Error:{}", listener.getClass().getSimpleName(), t);
}
}
//......
}
- set或者setFailure方法都会调用done方法
- done方法会调用notifyListeners,回调listener的operationCompleted或者operationFailed
小结
- ProducerImpl主要是为rocketmq自身的rocketmqProducer适配open-messaging的api接口
- 异步采用自定义的SendCallback回调和DefaultPromise
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