场景:我们需要在传输消息时得到结果

客服端在发送请求时会发送回调队列,服务端处理事情完成后会将结果返回到回调队列中,在增加关联标志关联每个请求和服务返回

客户端代码:

public class RPCClient {
    private final static String RPC_Queue_Name = "rpc_queue";
    public static void main(String[] args) throws IOException, TimeoutException, InterruptedException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();
        //声明队列
       
channel.queueDeclare(RPC_Queue_Name, false, false, false, null);

        //为每一个客户端获取一个随机的回调队列
       
String replyQueueName = channel.queueDeclare().getQueue();
        //为每一个客户端创建一个消费者(用于监听回调队列,获取结果)
       
QueueingConsumer consumer = new QueueingConsumer(channel);
        //消费者与队列关联
       
channel.basicConsume(replyQueueName, true, consumer);

        String response = null;
        String corrId = java.util.UUID.randomUUID().toString();

        //设置replyTocorrelationId属性值
       
AMQP.BasicProperties props = new AMQP.BasicProperties.Builder().correlationId(corrId).replyTo(replyQueueName).build();

        //发送消息到rpc_queue队列
       
channel.basicPublish("", RPC_Queue_Name, props, "8".getBytes());

        while (true) {
            QueueingConsumer.Delivery delivery = consumer.nextDelivery();
            if (delivery.getProperties().getCorrelationId().equals(corrId)) {
                response = new String(delivery.getBody(),"UTF-8");
                break;
            }
        }
        System.out.println( "fib(8) is " + response);
    }
}

服务端代码:

public class RPCServer {
    private final static String RPC_Queue_Name = "rpc_queue";
    public static void main(String[] args) throws IOException, TimeoutException, InterruptedException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();      channel.queueDeclare(RPC_Queue_Name,false,false,false,null);
        channel.basicQos(1);
        QueueingConsumer consumer = new QueueingConsumer(channel);
        channel.basicConsume(RPC_Queue_Name, false, consumer);
        System.out.println(" [x] Awaiting RPC requests");
        while (true) {
            QueueingConsumer.Delivery delivery = consumer.nextDelivery();
            //获取请求中的correlationId属性值,并将其设置到结果消息的correlationId属性中
           
BasicProperties props = delivery.getProperties();
            AMQP.BasicProperties replyProps = new AMQP.BasicProperties.Builder().correlationId(props.getCorrelationId()).build();
            //获取回调队列名字
           
String callQueueName = props.getReplyTo();

            String message = new String(delivery.getBody(),"UTF-8");

            System.out.println(" [.] fib(" + message + ")");

            //获取结果
           
String response = "" + fib(Integer.parseInt(message));
            //先发送回调结果
           
channel.basicPublish("", callQueueName, replyProps,response.getBytes());
            //后手动发送消息反馈
           
channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
        }
    }

    private static int fib(int i)
    {
        if(i==0) return 0;
        if (i==1) return 1;
        return fib(i-1) +fib(i-2);
    }
}
posted on 2017-07-16 10:47  Stark_Tan  阅读(282)  评论(0编辑  收藏  举报