Allowing Messages to Expire

By default, a message never expires. If a message will become obsolete after a certain period, however, you may want to set an expiration time. You can do this in either of two ways.

• You can use the setTimeToLive method of the MessageProducer interface to set a default expiration time for all messages sent by that producer. For example, the following call sets a time to live of one minute for a producer:

  producer.setTimeToLive(60000);

• You can use the long form of the send or the publish method to set an expiration time for a specific message. The fourth argument sets the expiration time in milliseconds. For example, the following send call sets a time to live of 10 seconds:

  producer.send(message, DeliveryMode.NON_PERSISTENT, 3, 10000);

If the specified timeToLive value is 0, the message never expires.

When the message is sent, the specified timeToLive is added to the current time to give the expiration time. Any message not delivered before the specified expiration time is destroyed. The destruction of obsolete messages conserves storage and computing resources.