There are ten levels of message priority in JMS. The ten levels of priority range from 0 (lowest) to 9 (highest). If you do not specify a priority level, the default level is 4. A JMS provider tries to deliver higher-priority messages before lower-priority ones but does not have to deliver messages in exact order of priority.

Message priority can be set:

• Using the setPriority method of the MessageProducer interface to set the priority level for all messages sent by that producer. For example, the following call sets a priority level of 7 for a producer:

producer.setPriority(7);

• Using the long form of the send or the publish method to set the priority level for a specific message. The third argument sets the priority level. For example, the following send call sets the priority level for message to 3:

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