JMS应用程序客户端可以创建多个活动会话，而Web / ejb组件不能？

... Note that the JMS API creates threads to deliver messages to 
message listeners. The use of this message listener facility may be 
limited by the restrictions on the use of threads in various 
containers. In EJB containers, for instance, it is typically not 
possible to create threads. The following methods must not be used by 
application components executing in containers that prevent them 
from creating threads: 
. 
- javax.jms.Session method setMessageListener 
- javax.jms.Session method getMessageListener 
- javax.jms.Session method run 
- javax.jms.QueueConnection method createConnectionConsumer 
- javax.jms.TopicConnection method createConnectionConsumer 
- javax.jms.TopicConnection method createDurableConnectionConsumer 
- javax.jms.MessageConsumer method getMessageListener 
- javax.jms.MessageConsumer method setMessageListener 
. 
In addition, use of the following methods on javax.jms.Connection
objects by applications in Web and EJB containers may interfere with the
connection management functions of the container and must not be used:
- setExceptionListener 
- stop
- setClientID 
A J2EE container may throw a JMSException if the application component 
violates these restrictions. ....