广播消息

原文链接        译者：小村长

什么是广播

广播是向所有用户发送消息。 如果您希望所有订阅者都能收到有关某个主题的消息，则广播是一个不错的选择。

生产者示例

[code lang=”java”]
public class BroadcastProducer {
public static void main(String[] args) throws Exception {
DefaultMQProducer producer = new DefaultMQProducer("ProducerGroupName");
producer.start();

for (int i = 0; i < 100; i++){
Message msg = new Message("TopicTest",
"TagA",
"OrderID188",
"Hello world".getBytes(RemotingHelper.DEFAULT_CHARSET));
SendResult sendResult = producer.send(msg);
System.out.printf("%s%n", sendResult);
}
producer.shutdown();
}
}
[/code]

消费者示例

[code lang=”java”]
public class BroadcastConsumer {
public static void main(String[] args) throws Exception {
DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("example_group_name");

consumer.setConsumeFromWhere(ConsumeFromWhere.CONSUME_FROM_FIRST_OFFSET);

//set to broadcast mode
consumer.setMessageModel(MessageModel.BROADCASTING);

consumer.subscribe("TopicTest", "TagA || TagC || TagD");

consumer.registerMessageListener(new MessageListenerConcurrently() {

@Override
public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs,
ConsumeConcurrentlyContext context) {
System.out.printf(Thread.currentThread().getName() + " Receive New Messages: " + msgs + "%n");
return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
}
});

consumer.start();
System.out.printf("Broadcast Consumer Started.%n");
}
}
[/code]