Question

我像这样创建了一个oracle队列

execute dbms_aqadm.create_queue_table (
                        queue_table => 'priorityqueue',
                        sort_list => 'PRIORITY,ENQ_TIME',
                        queue_payload_type => 'sys.aq$_jms_map_message',
                        compatible => '8.1.0');
execute dbms_aqadm.create_queue (
                        queue_name => 'priorityqueue',
                        queue_table => 'priorityqueue');
execute dbms_aqadm.start_queue (
                        queue_name => 'priorityqueue');

然后我使用spring JMSTemplate发送消息，如下所示：

ConnectionFactory connectionFactory = AQjmsFactory.getQueueConnectionFactory(dataSource);
JmsTemplate jmsTemplate = new JmsTemplate(connectionFactory);
jmsTemplate.setExplicitQosEnabled(true);
MessageCreator messageCreator = new MessageCreator() {
        @Override
        public Message createMessage(Session session) throws JMSException {
            MapMessage message = session.createMapMessage();
            // ... set some properties
            message.setJMSPriority(priority);
            return message;
        }
};
jmsTemplate.setPriority(priority);
jmsTemplate.send("priorityqueue", messageCreator);

如果我select来自priorityqueue的所有内容，我可以看到消息以不同的优先级放在那里：

select q_name, msgid, priority, state from priorityqueue;
Q_NAME                         MSGID                              PRIORITY      STATE
PRIORITYQUEUE                  1297D3F58D41208FE05400215A97112C          1          0 
PRIORITYQUEUE                  1297D3F58D43208FE05400215A97112C          9          0 
PRIORITYQUEUE                  1297D3F58D45208FE05400215A97112C          4          0

接下来我消费消息......没有任何花哨的东西 - 像这样：

ConnectionFactory connectionFactory = AQjmsFactory.getQueueConnectionFactory(oracleDataSource);

Connection connection = connectionFactory.createConnection();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
Queue loggerQueue = session.createQueue("priorityqueue");
MessageConsumer consumer = session.createConsumer(loggerQueue);

int count = 0;
while (true) {
    connection.start();
    Message message = consumer.receive(1000);
    if (message == null) {
        break;
    }
    count++;
    System.out.println(count + ".\tPriority [" + message.getJMSPriority() + "]");
}
connection.close();

但输出如下：

优先顺序[1]

优先顺序[4]

优先顺序[9]

什么时候真的应该是9,4,1。

documentation for java.jms.Message明确指出[t]he JMS API defines ten levels of priority value, with 0 as the lowest priority and 9 as the highest.

我做错了什么？我考虑使用优先级降序创建队列，但the CREATE_QUEUE_TABLE documentation表示sort_list是[t]he columns to be used as the sort key in ascending order，即它看起来不像降序是一种选择。

另外 - 发送时，我将优先级设置为两次 - 一次在消息上，一次在jmsTemplate上。我真的应该这样做吗？

Answer 1

Spring的JmsTemplate不支持每条消息的优先级。您需要按照本文所述继承JmsTemplate：https://aminsblog.wordpress.com/2010/04/27/publishing-qos-priority-enabled-messages-using-spring-jms-template-2/

public class QoSEnabledJmsTemplate extends JmsTemplate {
    protected void doSend(MessageProducer producer, Message message) throws JMSException {
       producer.send(message, getDeliveryMode(), message.getJMSPriority(), getTimeToLive());
    }
}

Oracle AQ按反向优先级顺序提供优先级JMS消息

1 个答案: