小程序该如何上架

生产者都是把消息给交换机，由交换机分发给消息队列。

routingKey：路由键，也可称为绑定，是交换机和队列之间的桥梁，交换机会根据routingKey来把消息转发到对应的队列。

Fanout

通用工具类：

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

public class RabbitMQUtil {
    public static Channel getChannel() throws Exception {
        //得到工厂
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        factory.setUsername("guest");
        factory.setPassword("guest");
        //生成连接
        Connection connection = factory.newConnection();
        //获取信道
        return connection.createChannel();
    }
}

生产者代码：创建一个Fanout Exchange。

import com.rabbitmq.client.BuiltinExchangeType;
import com.rabbitmq.client.Channel;

import java.util.Scanner;

public class FanoutProducer {

    private final static String EXCHANGE_NAME = "LogExchange";

    public static void main(String[] args) throws Exception {
        Channel channel = RabbitMQUtil.getChannel();

        channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.FANOUT);

        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext()) {
            String message = scanner.nextLine();
            channel.basicPublish(EXCHANGE_NAME, "", null, message.getBytes());
        }
    }
}

两个消费者代码：创建队列去绑定交换机

public class Consumer1 {
    private final static String FILE_QUEUE = "FileQueue";
    private final static String EXCHANGE_NAME = "LogExchange";

    public static void main(String[] args) throws Exception {
        Channel channel = RabbitMQUtil.getChannel();
        channel.queueDeclare(FILE_QUEUE, false, false, false, null);
        channel.queueBind(FILE_QUEUE, EXCHANGE_NAME, "");

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            System.out.printf("消息：%s,存储到磁盘%n", new String(delivery.getBody()));
        };
        channel.basicConsume(FILE_QUEUE, true, deliverCallback, consumerTag -> {});
    }
}

public class Consumer2 {
    private final static String CONSOLE_QUEUE = "ConsoleQueue";
    private final static String EXCHANGE_NAME = "LogExchange";

    public static void main(String[] args) throws Exception {
        Channel channel = RabbitMQUtil.getChannel();

        channel.queueDeclare(CONSOLE_QUEUE, false, false, false, null);
        channel.queueBind(CONSOLE_QUEUE, EXCHANGE_NAME, "");

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            System.out.printf("消息：%s,输出到控制台%n", new String(delivery.getBody()));
        };
        channel.basicConsume(CONSOLE_QUEUE, true, deliverCallback, consumerTag -> {});
    }
}

运行结果图如下。总结：在Fanout模式下，生产者生产消息发布到交换机后，交换机会把消息发送给所有与之绑定的队列，在该模式下，即使设置了routingKey也会无视它。

Direct

生产者代码：创建一个Direct交换机，发送消息到交换机同时指定routingKey。

import com.rabbitmq.client.BuiltinExchangeType;
import com.rabbitmq.client.Channel;

import java.util.Scanner;

public class DirectProducer {
    private final static String EXCHANGE_NAME = "LogExchange-Direct";

    public static void main(String[] args) throws Exception {
        Channel channel = RabbitMQUtil.getChannel();

        channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.DIRECT);

        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext()) {
            String message = scanner.nextLine();
            channel.basicPublish(EXCHANGE_NAME, "consoleRouteKey", null, message.getBytes());
        }
    }
}

消费者代码：让队列和交换机绑定，同时设置routingKey。

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DeliverCallback;

public class Consumer1 {
    private final static String FILE_QUEUE = "FileQueue";
    private final static String EXCHANGE_NAME = "LogExchange-Direct";


    public static void main(String[] args) throws Exception {
        Channel channel = RabbitMQUtil.getChannel();
        channel.queueDeclare(FILE_QUEUE, false, false, false, null);
        channel.queueBind(FILE_QUEUE, EXCHANGE_NAME, "fileRouteKey");

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            System.out.printf("消息：%s,存储到磁盘%n", new String(delivery.getBody()));
        };
        channel.basicConsume(FILE_QUEUE, true, deliverCallback, consumerTag -> {});
    }
}

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DeliverCallback;

public class Consumer2 {
    private final static String CONSOLE_QUEUE = "ConsoleQueue";
    private final static String EXCHANGE_NAME = "LogExchange-Direct";


    public static void main(String[] args) throws Exception {
        Channel channel = RabbitMQUtil.getChannel();

        channel.queueDeclare(CONSOLE_QUEUE, false, false, false, null);
        channel.queueBind(CONSOLE_QUEUE, EXCHANGE_NAME, "consoleRouteKey");

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            System.out.printf("消息：%s,输出到控制台%n", new String(delivery.getBody()));
        };
        channel.basicConsume(CONSOLE_QUEUE, true, deliverCallback, consumerTag -> {});
    }
}

执行结果如图，总结：在Direct模式下，交换机会根据routingKey把消息给相关的队列，如果没有这样的队列，消息会被丢弃。

Topic

该模式下的routingKey的命名是一个单词列表，以点号分隔开。例如：“log.error.console”。其中可以用 *(星号)可以代替一个位置，#(井号)可以替代零个或多个位置。

比如：现在队列Q1和交换机之间设置的routingKey为 *.orange.*

队列Q2和交换机之间设置的routingKey为 *.*.rabbit*、lazy.#

实际测试代码

import com.rabbitmq.client.Channel;

import java.util.HashMap;
import java.util.Map;

public class TopicProducer {
    private final static String EXCHANGE_NAME = "LogExchange-Topic";

    public static void main(String[] args) throws Exception {
        Channel channel = RabbitMQUtil.getChannel();

        HashMap<String, String> bindingKeyMap = new HashMap<>();
        bindingKeyMap.put("quick.orange.rabbit", "1.被队列 Q1Q2 接收到");
        bindingKeyMap.put("lazy.orange.elephant", "2.被队列 Q1Q2 接收到");
        bindingKeyMap.put("quick.orange.fox", "3.被队列 Q1 接收到");
        bindingKeyMap.put("lazy.brown.fox", "4.被队列 Q2 接收到");
        bindingKeyMap.put("lazy.pink.rabbit", "5.虽然满足两个绑定但只被队列 Q2 接收一次");
        bindingKeyMap.put("quick.brown.fox", "6.不匹配任何绑定不会被任何队列接收到会被丢弃");
        bindingKeyMap.put("quick.orange.male.rabbit", "7.是四个单词不匹配任何绑定会被丢弃");
        bindingKeyMap.put("lazy.orange.male.rabbit", "8.是四个单词但匹配 Q2");
        for (Map.Entry<String,String> bindingKeyEntry : bindingKeyMap.entrySet()){
            String routingKey = bindingKeyEntry.getKey();
            String message = bindingKeyEntry.getValue();
            channel.basicPublish(EXCHANGE_NAME,routingKey,null,message.getBytes("UTF-8"));
            System.out.println("生产者发出消息:"+message);
        }
    }
}

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DeliverCallback;

public class Consumer1 {
    private final static String FILE_QUEUE = "FileQueue";
    private final static String EXCHANGE_NAME = "LogExchange-Topic";


    public static void main(String[] args) throws Exception {
        Channel channel = RabbitMQUtil.getChannel();
        channel.queueDeclare(FILE_QUEUE, false, false, false, null);
        channel.queueBind(FILE_QUEUE, EXCHANGE_NAME, "*.orange.*");

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            System.out.printf("消息：%s,存储到磁盘%n", new String(delivery.getBody()));
        };
        channel.basicConsume(FILE_QUEUE, true, deliverCallback, consumerTag -> {});
    }
}

public class Consumer2 {
    private final static String CONSOLE_QUEUE = "ConsoleQueue";
    private final static String EXCHANGE_NAME = "LogExchange-Topic";


    public static void main(String[] args) throws Exception {
        Channel channel = RabbitMQUtil.getChannel();

        channel.queueDeclare(CONSOLE_QUEUE, false, false, false, null);
        channel.queueBind(CONSOLE_QUEUE, EXCHANGE_NAME, "*.*.rabbit");
        channel.queueBind(CONSOLE_QUEUE, EXCHANGE_NAME, "lazy.#");

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            System.out.printf("消息：%s,输出到控制台%n", new String(delivery.getBody()));
        };
        channel.basicConsume(CONSOLE_QUEUE, true, deliverCallback, consumerTag -> {});
    }
}

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