Java消息传递服务-消息未被接收

Question

我正在使用NetBeans IDE和Java EE与glassfish3服务器编写程序。目前我有两个线程，A和b。它们都在彼此之间来回发送消息。我遇到的问题是:

1.  A sends a message, M1, to B
2.  B receives M1
3.  B sends M2 to A
4.  A hangs waiting on M2

下面是我的代码:

线程:

//required declarations
producer = session.createProducer(AtoBQueue);
m1 = session.createMapMessage();
m1.setString("m1", "m1Val");
m1.setJMSReplyTo(BtoAQueue);
flag = true;
producer.send(m1);
consumer = session.createConsumer(BtoAQueue);
connection.start();
if(flag){
   m2 = (MapMessage) consumer.receive();
   String m2Val = m2.getString("m2");
   if(m2Val.equals("true")){
      flag2 = true;
   }
}
...

线程B:

consumer = session.createConsumer(AtoBQueue);
connection.start();
while(true){
   m1 = (MapMessage) consumer.receive();
   m1Val = m1.getString("m1");
   if(m1Val != null){
      flag = true;
   }
   MessageProducer producer = session.createProducer((Queue m1.getJMSReplyTo());
   m2 = session.createMapMessage();
   if(m1Val != null){
      if(m1Val.equals("m1Val")){
         m2.setString("m2", "m2Val");
         m2.setJMSReplyTo(AtoBQueue);
         producer.send(m2);
      }
   }
   ...
}

Answer 1

您的线程A将密钥发送为"报告"，而您期望线程B为"m1"，因此它不会将回复发送回队列。在发送消息之前，还可以尝试在A中创建Consumer。

Answer 2

事实证明，我需要在只为线程b执行producer.send(message)之后添加session.commit()。