Per weblogic certification book, the default transaction level is:

Session Bean: Supports
Entity Bean: Required

Google so much but found none.

参考: http://dev2dev.bea.com.cn/techdoc/200508633.html

出于无奈, 我只好在自己的电脑上单机配置了一个 Distributed Topic , 它的 JNDI 是 testtopic, 然后让它指向配置在同一台电脑上的两个 JMS Server 下的两个 Topic: testtopic1 和 testtopic2, 然后我写了一个 MDB, 改了 JNDI 地址让它们分别处理来自 testtopic1 和 testtopic2 的消息, 客户端通过连接 testtopic 这个地址发消息... 结果可想而知, 竟然出现如下结果:

<2006-12-12 下午19时28分16秒 CST> <Notice> <WebLogicServer> <BEA-000355> <Thread
"ListenThread.Default" listening on port 7001, ip address *.*>
ejbCreate()
ejbCreate()
JMS Bean 1: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 0
JMS Bean 2: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 0
JMS Bean 2: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 1
JMS Bean 1: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 1
JMS Bean 1: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 2
JMS Bean 2: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 2
ejbCreate()
JMS Bean 1: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 3
ejbCreate()
ejbCreate()
ejbCreate()
ejbCreate()
ejbCreate()
ejbCreate()
ejbCreate()
ejbCreate()
ejbCreate()
ejbCreate()
ejbCreate()
ejbCreate()
JMS Bean 2: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 3
JMS Bean 2: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 4
JMS Bean 1: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 4
JMS Bean 2: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 5
JMS Bean 1: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 5
JMS Bean 1: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 6
JMS Bean 2: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 6
JMS Bean 2: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 7
JMS Bean 1: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 7
JMS Bean 2: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 8
JMS Bean 1: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 8
JMS Bean 2: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 9
JMS Bean 1: Received new message : Tue Dec 12 19:37:11 CST 2006 This is a test m
essage of 9

自己先寒一下... 两个 Bean 差不多都收到了消息... 不知道分布式环境中是不是还是一样的结果呢? 期待 JMS 集群高手指点啊.....

附带一下代码:

package examples;

import javax.ejb.*;
import javax.jms.*;

/**
* Sample Message-Driven Bean
*/
public class LogBean implements MessageDrivenBean, MessageListener {

protected MessageDrivenContext ctx;

/**
* Associates this Bean instance with a particular context.
*/
public void setMessageDrivenContext(MessageDrivenContext ctx) {
this.ctx = ctx;
}

/**
* Initializes the bean
*/
public void ejbCreate() {
System.err.println("ejbCreate()");
}

/**
* Our one business method
*/
public void onMessage(Message msg) {

TextMessage tm = (TextMessage) msg;

try {
String text = tm.getText();
System.err.println("JMS Bean 2: Received new message : " + text);
}
catch(JMSException e) {
e.printStackTrace();
}
}

/**
* Destroys the bean
*/
public void ejbRemove() {
System.err.println("ejbRemove()");
}
}

import javax.naming.*;

import javax.jms.*;
import java.util.*;

public class Client {

public static void main (String[] args) throws Exception {

// Initialize JNDI
Context ctx = new InitialContext(System.getProperties());

// 1: Lookup ConnectionFactory via JNDI
TopicConnectionFactory factory =
(TopicConnectionFactory)
ctx.lookup("javax.jms.TopicConnectionFactory");

// 2: Use ConnectionFactory to create JMS connection
TopicConnection connection =
factory.createTopicConnection();

// 3: Use Connection to create session
TopicSession session = connection.createTopicSession(
false, Session.AUTO_ACKNOWLEDGE);

// 4: Lookup Desintation (topic) via JNDI
Topic topic = (Topic) ctx.lookup("testtopic");

// 5: Create a Message Producer
TopicPublisher publisher = session.createPublisher(topic);

// 6: Create a text message, and publish it
for(int i = 0; i < 10; i++) {
TextMessage msg = session.createTextMessage();
msg.setText(new java.util.Date() + " This is a test message of " + i);
publisher.publish(msg);
}

}
}

General


Thresholds & Quotas


Members

You can configure multiple physical JMS topics as members of a single set of distributed topics. WebLogic JMS distributes the messaging load across all available topic members within the distributed topic. When a topic member becomes unavailable, traffic is then redirected toward other available topic members in the set.

This JMS Distributed Topic Members page displays key information about each member that has been configured for this distributed topic.

Configure a new Distributed Topic Member...

Name
JMS Topic
Weight

MyDistributed Topic Member
MyJMS Topic
1

MyDistributed Topic Member-1
MyJMS Topic-1
1