• rabbitMq交换机direct、topics


    一: direct

    上面我用采用了广播的模式进行消息的发送,现在我们采用路由的方式对不同的消息进行过滤

    发送端代码

    复制代码
    public class RoutingSendDirect {
        private static final String EXCHANGE_NAME = "direct_logs";
        // 路由关键字
        private static final String[] routingKeys = new String[]{"info" ,"warning", "error"};
        public static void main(String[] args) throws IOException, TimeoutException {
            ConnectionFactory factory = new ConnectionFactory();
            factory.setHost("localhost");
            Connection connection = factory.newConnection();
            Channel channel = connection.createChannel();
            //声明交换机
            channel.exchangeDeclare(EXCHANGE_NAME,"direct");//注意是direct
            //发送信息
            for (String routingKey:routingKeys){
                String message = "RoutingSendDirect Send the message level:" + routingKey;
                channel.basicPublish(EXCHANGE_NAME,routingKey,null,message.getBytes());
                System.out.println("RoutingSendDirect Send"+routingKey +"':'" + message);
            }
            channel.close();
            connection.close();
        }
    }
    复制代码
    ReceiveLogsDirect1 消费者代码
    复制代码
    public class ReceiveLogsDirect1 {
        // 交换器名称
        private static final String EXCHANGE_NAME = "direct_logs";
        // 路由关键字
        private static final String[] routingKeys = new String[]{"info" ,"warning"};
    
        public static void main(String[] args) throws IOException, TimeoutException {
            ConnectionFactory factory = new ConnectionFactory();
            factory.setHost("localhost");
            Connection connection = factory.newConnection();
            Channel channel = connection.createChannel();
            //声明交换器
            channel.exchangeDeclare(EXCHANGE_NAME, "direct");
            //获取匿名队列名称
            String queueName=channel.queueDeclare().getQueue();
    
            //根据路由关键字进行绑定
            for (String routingKey:routingKeys){
                channel.queueBind(queueName,EXCHANGE_NAME,routingKey);
                System.out.println("ReceiveLogsDirect1 exchange:"+EXCHANGE_NAME+"," +
                        " queue:"+queueName+", BindRoutingKey:" + routingKey);
            }
            System.out.println("ReceiveLogsDirect1  Waiting for messages");
            Consumer consumer = 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("ReceiveLogsDirect1 Received '" + envelope.getRoutingKey() + "':'" + message + "'");
                }
            };
            channel.basicConsume(queueName, true, consumer);
        }
    复制代码
    ReceiveLogsDirect2消费者代码
    复制代码
    public class ReceiveLogsDirect2 {
        // 交换器名称
        private static final String EXCHANGE_NAME = "direct_logs";
        // 路由关键字
        private static final String[] routingKeys = new String[]{"error"};
    
        public static void main(String[] argv) throws Exception {
            ConnectionFactory factory = new ConnectionFactory();
            factory.setHost("localhost");
            Connection connection = factory.newConnection();
            Channel channel = connection.createChannel();
            //声明交换器
            channel.exchangeDeclare(EXCHANGE_NAME, "direct");
            //获取匿名队列名称
            String queueName = channel.queueDeclare().getQueue();
            //根据路由关键字进行多重绑定
            for (String severity : routingKeys) {
                channel.queueBind(queueName, EXCHANGE_NAME, severity);
                System.out.println("ReceiveLogsDirect2 exchange:"+EXCHANGE_NAME+", queue:"+queueName+", BindRoutingKey:" + severity);
            }
            System.out.println("ReceiveLogsDirect2 Waiting for messages");
    
            Consumer consumer = new DefaultConsumer(channel) {
                @Override
                public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws UnsupportedEncodingException {
                    String message = new String(body, "UTF-8");
                    System.out.println("ReceiveLogsDirect2 Received '" + envelope.getRoutingKey() + "':'" + message + "'");
                }
            };
            channel.basicConsume(queueName, true, consumer);
        }
    }
    复制代码

    上面代码可以看出这里是通过路由来找个这个对列的。我们看下结果

    二:Topics

    这种应该属于模糊匹配

    * :可以替代一个词

    #:可以替代0或者更多的词

    现在我们继续看看代码来理解

    发送端

    复制代码
    public class TopicSend {
        private static final String EXCHANGE_NAME = "topic_logs";
    
        public static void main(String[] args) throws IOException, TimeoutException {
            Connection connection = null;
            Channel channel = null;
            try{
                ConnectionFactory factory=new ConnectionFactory();
                factory.setHost("localhost");
                connection=factory.newConnection();
                channel=connection.createChannel();
    
                //声明一个匹配模式的交换机
                channel.exchangeDeclare(EXCHANGE_NAME,"topic");
                //待发送的消息
                String[] routingKeys=new String[]{
                        "quick.orange.rabbit",
                        "lazy.orange.elephant",
                        "quick.orange.fox",
                        "lazy.brown.fox",
                        "quick.brown.fox",
                        "quick.orange.male.rabbit",
                        "lazy.orange.male.rabbit"
                };
                //发送消息
                for(String severity :routingKeys){
                    String message = "From "+severity+" routingKey' s message!";
                    channel.basicPublish(EXCHANGE_NAME, severity, null, message.getBytes());
                    System.out.println("TopicSend Sent '" + severity + "':'" + message + "'");
                }
            }catch (Exception e){
                e.printStackTrace();
                if (connection!=null){
                    channel.close();
                    connection.close();
                }
            }finally {
                if (connection!=null){
                    channel.close();
                    connection.close();
                }
            }
        }
    }
    复制代码

    消费者1:

    复制代码
    public class ReceiveLogsTopic1 {
        private static final String EXCHANGE_NAME = "topic_logs";
    
        public static void main(String[] args) throws IOException, TimeoutException {
            ConnectionFactory factory = new ConnectionFactory();
            factory.setHost("localhost");
            Connection connection = factory.newConnection();
            Channel channel = connection.createChannel();
    
            //声明一个匹配模式的交换机
            channel.exchangeDeclare(EXCHANGE_NAME, "topic");
            String queueName = channel.queueDeclare().getQueue();
            //路由关键字
            String[] routingKeys = new String[]{"*.orange.*"};
            //绑定路由
            for (String routingKey : routingKeys) {
                channel.queueBind(queueName, EXCHANGE_NAME, routingKey);
                System.out.println("ReceiveLogsTopic1 exchange:" + EXCHANGE_NAME + ", queue:" + queueName + ", BindRoutingKey:" + routingKey);
            }
            System.out.println("ReceiveLogsTopic1 Waiting for messages");
    
            Consumer consumer = 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("ReceiveLogsTopic1 Received '" + envelope.getRoutingKey() + "':'" + message + "'");
                }
            };
            channel.basicConsume(queueName, true, consumer);
        }
    }
    复制代码

    消费者2:

    复制代码
    
    ublic class ReceiveLogsTopic2 {
        private static final String EXCHANGE_NAME = "topic_logs";
    
        public static void main(String[] argv) throws IOException, TimeoutException {
            ConnectionFactory factory = new ConnectionFactory();
            factory.setHost("localhost");
            Connection connection = factory.newConnection();
            Channel channel = connection.createChannel();
    //      声明一个匹配模式的交换器
            channel.exchangeDeclare(EXCHANGE_NAME, "topic");
            String queueName = channel.queueDeclare().getQueue();
            // 路由关键字
            String[] routingKeys = new String[]{"*.*.rabbit", "lazy.#"};
    //      绑定路由关键字
            for (String bindingKey : routingKeys) {
                channel.queueBind(queueName, EXCHANGE_NAME, bindingKey);
                System.out.println("ReceiveLogsTopic2 exchange:"+EXCHANGE_NAME+", queue:"+queueName+", BindRoutingKey:" + bindingKey);
            }
    
            System.out.println("ReceiveLogsTopic2 Waiting for messages");
    
            Consumer consumer = new DefaultConsumer(channel) {
                @Override
                public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws UnsupportedEncodingException  {
                    String message = new String(body, "UTF-8");
                    System.out.println("ReceiveLogsTopic2 Received '" + envelope.getRoutingKey() + "':'" + message + "'");
                }
            };
            channel.basicConsume(queueName, true, consumer);
        }
    }
    

    三,远程调用

    public class RPCServer {
        private static final String RPC_QUEUE_NAME = "rpc_queue";
        private static int fib(int n) {
            if (n == 0) {
                return 0;
            }
            if (n == 1) {
                return 1;
            }
            return fib(n - 1) + fib(n - 1);
        }
        public static void main(String[] args) throws IOException, InterruptedException, TimeoutException {
            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("RPCServer Awating RPC request");
            while (true) {
                QueueingConsumer.Delivery delivery = consumer.nextDelivery();
                BasicProperties props = delivery.getProperties();
                BasicProperties replyProps = new AMQP.BasicProperties.Builder().
                        correlationId(props.getCorrelationId()).build();
    
                String message = new String(delivery.getBody(), "UTF-8");
                int n = Integer.parseInt(message);
    
                System.out.println("RPCServer fib(" + message + ")");
                String response = "" + fib(n);
                channel.basicPublish( "", props.getReplyTo(), replyProps, response.getBytes());
                channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
            }
        }
    }
    

     服务器代码比较简单
    1:建立连接,通道,队列
    2:我们可能运行多个服务器进程,为了分散负载服务器压力,我们设置channel.basicQos(1);
    3:我们用basicconsume访问队列。然后进入循环,在其中我们等待请求消息并处理消息然后发送响应。

    public class RPCClient {
        private Connection connection;
        private Channel channel;
        private String requestQueueName = "rpc_queue";
        private String replyQueueName;
        private QueueingConsumer consumer;
        public RPCClient() throws IOException, TimeoutException {
            ConnectionFactory factory = new ConnectionFactory();
            factory.setHost("localhost");
            connection = factory.newConnection();
            channel = connection.createChannel();
    
            replyQueueName = channel.queueDeclare().getQueue();
            consumer = new QueueingConsumer(channel);
            channel.basicConsume(replyQueueName, true, consumer);
        }
        public String call(String message) throws IOException, InterruptedException {
            String response;
            String corrID = UUID.randomUUID().toString();
            AMQP.BasicProperties props = new AMQP.BasicProperties().builder()
                    .correlationId(corrID).replyTo(replyQueueName).build();
            channel.basicPublish("", requestQueueName, props, message.getBytes("UTF-8"));//发送消息等待服务端返回
            while (true) {
                QueueingConsumer.Delivery delivery = consumer.nextDelivery();//服务端响应后 阻塞解除
                if (delivery.getProperties().getCorrelationId().equals(corrID)) {
                    response = new String(delivery.getBody(), "UTF-8");
                    break;
                }
            }
            return response;
        }
        public void close() throws Exception {
            connection.close();
        }
        public static void main(String[] args) throws Exception {
            RPCClient rpcClient = null;
            String response;
            try {
                rpcClient = new RPCClient();
                System.out.println("RPCClient  Requesting fib(20)");
                response = rpcClient.call("20");
                System.out.println("RPCClient  Got '" + response + "'");
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                if (rpcClient != null) {
                    rpcClient.close();
                }
            }
        }
    }
    

     客户端代码解读
    1:建立一个连接和通道,并声明了一个唯一的“回调”队列的答复
    2:我们订阅回调队列,这样就可以得到RPC的响应
    3:定义一个call方法用于发送当前的回调请求
    4:生成一个唯一的correlationid,然后通过while循环来捕获合适的回应
    5:我们请求信息,发送2个属性,replyTo 和correlationId
    6:然后就是等待直到有合适的回应到达
    7:while循环是做一个非常简单的工作,对于每一个响应消息,它检查是否有correlationid然后进行匹配。然后是就进行响应。
    8:最后把响应返回到客户端。

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  • 原文地址:https://www.cnblogs.com/xingminghui/p/8650396.html
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