throws Exception {
this.messages = new ArrayList<Message>();
for (int j = 0; j < num; j++) {
// ��Ҫ����topic
final MessageProducer messageProducer = this.producerList.get(j);
messageProducer.publish(topic);
for (int i = 0; i < count; i++) {
final byte[] data = ("hello" + j + i).getBytes();
final Message msg = new Message(topic, data);
messageProducer.beginTransaction();
final SendResult result = messageProducer.sendMessage(msg);