Question

我正在尝试使用RabbitMQ Publisher和Consumer做一个简单的应用程序，生成器是用Java编写的，而消费者是在Scala中。

这是我正在使用的发布者，它成功地将数据插入rabbitMQ服务器中的“queue1”队列：

String queue="queue1";


String exchange="queue1";
String routing_key="queue1";
Connection connection = factory.newConnection();
Channel channel = connection.createChannel();
channel.queueDeclare(queue, true, false, false, null);
channel.exchangeDeclare(exchange, "direct");
channel.queueBind(queue,exchange,routing_key);
channel.basicQos(1);

String msg = "Hello";

channel.basicPublish(exchange,routing_key_one, new AMQP.BasicProperties.Builder().contentType("text/plain").deliveryMode(1).priority(0).
build(),msg.getBytes());
channel.close();
connection.close();

现在的问题是，我在一个单独的脚本上有一个Consumer，但我不能让它返回我从发布者发送的“msg”字符串;我只能将consumer-tag作为返回值。这是我的消费者：

import com.rabbitmq.client.{ConnectionFactory,Connection,Channel,Consumer,DefaultConsumer,Envelope,BasicProperties}

val rabbit_host="localhost"
val queue="queue1"
val exchange="queue1"
val routing_key="queue1"

val factory: ConnectionFactory = new ConnectionFactory()
factory.setHost (rabbit_host)

val connection: Connection = factory.newConnection()
val channel: Channel = connection.createChannel()

channel.queueBind(queue_name, exchange, routing_key, null)
channel.basicQos(1)

val consumer:Consumer=new DefaultConsumer(channel){
  def handleDelivery(consumerTag: String, envelope: Envelope, properties: BasicProperties, body: Array[Byte]):String ={
    new String(body,"UTF-8")
  }
}


val msg: String = channel.basicConsume(queue_name,true, consumer)


channel.close()
connection.close()

如果我打印“msg”，这就是我得到的值：“amq.ctag-miRiLnyTcsq9MwzHyVshZw”

所以我的问题是，有没有办法让我得到“hello”（原始值）作为basicConsume函数的返回？

感谢您的时间。

Answer 1

根据文件

val msg: String = channel.basicConsume(queue_name,true, consumer)

返回

与新消费者相关联的consumerTag

由于rabbitMq的异步性质，等待消息并不容易。您可以尝试使用Promise并阻止结果

val p = Promise[String]()
val f = p.future

val consumer:Consumer=new DefaultConsumer(channel){
  def handleDelivery(consumerTag: String, envelope: Envelope, properties: BasicProperties, body: Array[Byte]):String ={
    val parsedBody = new String(body,"UTF-8")
    p.success(parsedBody)
  }
}
val msg: String = Await.result(f, 5 seconds)

RabbitMQ - 如何使用DefaultConsumer从使用者标记中提取邮件正文？

1 个答案: