通过使用“*”和“#”，使来自不同源头的消息到达同一个队列，”.”将路由键分为了几个标识符，“*”匹配1个，“#”匹配一个或多个。例如日志处理：

假设有交换器log-exchange，

日志级别有error,info,warning，

应用模块有user,order,email，

服务器有 A、B、C、D

路由键的规则为 服务器+“.”+日志级别+“.”+应用模块名，如：A. info .email。

1、要关注A服务器发送的所有应用错误的消息，怎么做？

声明队列名称为“a-app-error-queue”并绑定到交换器上：channel. queueBind (‘a-app-error-queue’,’logs-change’,’A.error.*’)

2、关注B服务器发送的的所有日志，怎么办？

声明队列名称为“b-all-queue”并绑定到交换器上：channel. queueBind (b-all-queue’,’logs-change’,’ B.#’)或channel. queueBind (b-all-queue’,’logs-change’,’ B.*.*’)

3、关注所有服务器发送的email的所有日志，怎么办？

声明队列名称为“email-all-queue”并绑定到交换器上：channel. queueBind (email -all-queue’,’logs-change’,’ *.*.emal’)

4、想要接收所有日志：channel->queue_bind(‘all-log’,’logs-change’,’#’)

生产者：

public class TopicProducer {

    public final static String EXCHANGE_NAME = "topic_logs";

    public static void main(String[] args)
            throws IOException, TimeoutException {
        /**
         * 创建连接连接到RabbitMQ
         */
        ConnectionFactory factory = new ConnectionFactory();
        // 设置MabbitMQ所在主机ip或者主机名
        factory.setHost("127.0.0.1");

        // 创建一个连接
        Connection connection = factory.newConnection();

        // 创建一个信道
        Channel channel = connection.createChannel();
        // 指定转发
        channel.exchangeDeclare(EXCHANGE_NAME,
                BuiltinExchangeType.TOPIC);

        /*日志消息，路由键最终格式类似于：info.order.B*/
        String[] severities={"error","info","warning"};
        for(int i=0;i<3;i++){
            String[]  modules={"user","order","email"};
            for(int j=0;j<3;j++){
                String[]  servers={"A","B","C"};
                for(int k=0;k<3;k++){
                    // 发送的消息
                    String message = "Hello Topic_["+i+","+j+","+k+"]";
                    String routeKey = severities[i%3]+"."+modules[j%3]
                            +"."+servers[k%3];
                    channel.basicPublish(EXCHANGE_NAME,routeKey,
                            null, message.getBytes());
                    System.out.println(" [x] Sent '" + routeKey +":'"
                            + message + "'");
                }
            }

        }
        // 关闭频道和连接
        channel.close();
        connection.close();
    }

}

消费者（ServerB的全部消息）：

public class ServerBAllConsumer {

    public static void main(String[] argv) throws IOException,
            InterruptedException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("127.0.0.1");

        // 打开连接和创建频道，与发送端一样
        Connection connection = factory.newConnection();
        final Channel channel = connection.createChannel();

        channel.exchangeDeclare(TopicProducer.EXCHANGE_NAME,
                BuiltinExchangeType.TOPIC);
        // 声明一个随机队列
        String queueName = channel.queueDeclare().getQueue();

        channel.queueBind(queueName,TopicProducer.EXCHANGE_NAME,
                "#.B");

        System.out.println(" [*] Waiting for messages:");

        // 创建队列消费者
        final Consumer consumerA = new DefaultConsumer(channel) {
            @Override
            public void handleDelivery(String consumerTag,
                                       Envelope envelope,
                                       AMQP.BasicProperties properties,
                                       byte[] body)
                    throws IOException {
                String message = new String(body, "UTF-8");
                System.out.println(" AllConsumer Received "
                        + envelope.getRoutingKey()
                        + "':'" + message + "'");
            }
        };
        channel.basicConsume(queueName, true, consumerA);
    }
}

消费者（ServerA的ERROR消息）：

// 声明一个随机队列
        String queueName = channel.queueDeclare().getQueue();

        channel.queueBind(queueName,TopicProducer.EXCHANGE_NAME,
                "error.*.A");

        System.out.println(" [*] Waiting for messages:");

消费者（所有的ERROR消息）：

// 声明一个随机队列
        String queueName = channel.queueDeclare().getQueue();

        channel.queueBind(queueName,TopicProducer.EXCHANGE_NAME,
                "error.#");

        System.out.println(" [*] Waiting for messages:");

消费者（所有的EMAIl消息）：

// 声明一个随机队列
        String queueName = channel.queueDeclare().getQueue();

        channel.queueBind(queueName,TopicProducer.EXCHANGE_NAME,
                "*.email.*");

        System.out.println(" [*] Waiting for messages:");

消费者（所有的消息）：

// 声明一个随机队列
        String queueName = channel.queueDeclare().getQueue();

        channel.queueBind(queueName,TopicProducer.EXCHANGE_NAME,
                "#");

        System.out.println(" [*] Waiting for messages:");