Spring Integration-设置发送消息的上限

Question

I am writing a mail service that replies to incoming messages and I'd like to set up a limit - max 10 sent messages/hour. It should reset at full hour too.

Is it possible in Spring Integration? I read about Task Scheduling in Spring docs, but I'm not sure if that matches my case. I guess I could set up a CronTrigger that sends the messages at a fixed rate, but that doesn't sound like it does what I actually want to achieve.

Thanks in advance.

Answer 1

I think you go right way though.

You configure a QeueueChannel and PollingConsumer ( @ServiceActivator with the @Poller ). You definitely can go the cron trigger there:

/**
 * @return The cron expression to create the {@link CronTrigger}.
 * Can be specified as 'property placeholder', e.g. {@code ${poller.cron}}.
 */
String cron() default "";

And your requirement about max 10 sent messages/hour ca be achieved with the:

/**
 * @return The maximum number of messages to receive for each poll.
 * Can be specified as 'property placeholder', e.g. {@code ${poller.maxMessagesPerPoll}}.
 * Defaults to -1 (infinity) for polling consumers and 1 for polling inbound channel adapters.
 */
String maxMessagesPerPoll() default "";

So, when the task is performed by the scheduler according the configured cron time, only configured maxMessagesPerPoll will be pulled from the QeueueChannel and sent downstream for processing (sending emails).

See more info in the https://docs.spring.io/spring-integration/docs/5.0.0.RELEASE/reference/html/messaging-channels-section.html#polling-consumer and seek for the Important: Poller Configuration paragraph.