我使用rocketmq-spring发送的消息版本是2.1.0，有时我得到了ConcurrentModificationException在org.apache.rocketmq.common.message.MessageDecoder.messageProperties2String(MessageDecoder.java:414)，以下是一个详细的日志。谢谢!
#[xx, 10.xx.52] INFO 2022-05-07 15:31:11.043 [XNIO-1 task-74, 29de7f06241a3313, 29de7f06241a3313] com.xx.common.IpProducerService.asyncSendMessage:45 - contentMap{refNo=xx, system=xx, ip=null, platformId=xx, userId=xxx}
#[fp, 10.xx.52] INFO 2022-05-07 15:31:11.043 [XNIO-1 task-74, 29de7f06241a3313, 29de7f06241a3313] com.xx.rocketmq.producer.RocketMqProducer.asyncInfo:19 - -=-=-= [Async Sending Message] -=-=-=
Topic = TOPIC_xx_xx
Tag =
MessageId = null
DelayLevel = 0
Content = {"refNo":"xx","system":"xx","platformId":"xx","userId":"xx"}
#[fp, 10.xx.52] ERROR 2022-05-07 15:31:11.044 [AsyncSenderExecutor_3, , ] com.xx.rocketmq.producer.ProduceCallBack.onException:32 - asyncSendMessage caused exception.
java.util.ConcurrentModificationException: null
at java.util.HashMap$HashIterator.nextNode(HashMap.java:1437)
at java.util.HashMap$EntryIterator.next(HashMap.java:1471)
at java.util.HashMap$EntryIterator.next(HashMap.java:1469)
at org.apache.rocketmq.common.message.MessageDecoder.messageProperties2String(MessageDecoder.java:414)
at org.apache.rocketmq.client.impl.producer.DefaultMQProducerImpl.sendKernelImpl(DefaultMQProducerImpl.java:790)
at org.apache.rocketmq.client.impl.producer.DefaultMQProducerImpl.sendDefaultImpl(DefaultMQProducerImpl.java:584)
at org.apache.rocketmq.client.impl.producer.DefaultMQProducerImpl.access$300(DefaultMQProducerImpl.java:97)
at org.apache.rocketmq.client.impl.producer.DefaultMQProducerImpl$4.run(DefaultMQProducerImpl.java:511)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
#[xx, 10.xx.52] INFO 2022-05-07 15:31:11.044 [AsyncSenderExecutor_3, , ] com.xx.common.IpProducerService.handleResult:49 - async produce status is F使用不同的rocketMQTemplates实例发送相同的消息
asyncSend是在rocketMQTemplates的ThreadPool上做的，那里有很多线程，所以你不能使用不同的rocketMQTemplates发送相同的消息(相同的消息使用相同的属性HashMap，不是线程安全的)。