如何使用Grails和JMS/ActiveMQ配置独占消费者？

Question

另外，JMS使用什么标准来确定一个专属消费者何时死亡或消失？

// resources.groovy
beans = {
    jmsConnectionFactory(org.apache.activemq.ActiveMQConnectionFactory) { 
    brokerURL top://example.com:1234 
    userName = 'user' 
    password = 'password' 
    } 
} 

class TestService { 

static exposes = ["jms"] 
static destination = "SOME_TOPIC_NAME" 
static isTopic = true 

def onMessage(msg) { 
    // handle message 

    // explicitly return null to prevent unwanted replyTo attempt 
    return null 
} 

} 

Answer 1

首先，您的示例使用主题，这是行不通的；您需要队列：

class TestService { 
  static expose = ["jms"] 
  static destination = "MYQUEUE" 
  ...
}

在ActiveMQ中配置独占使用者非常简单：

queue = new ActiveMQQueue("MYQUEUE?consumer.exclusive=true");

..但是Grails插件可能很棘手；您可以试试这些：

class TestService { 
  static expose = ["jms"] 
  static destination = "MYQUEUE?consumer.exclusive=true" 
  def onMessage(msg){ ...}
}


class TestService { 
  static expose = ["jms"] 
  @Queue(
     name = "MYQUEUE?consumer.exclusive=true" 
  )
  def handleMessage(msg){ ...}
}