RabbitMQ--交换机

目录

绑定 bindings

Fanout exchange

#Fanout 介绍

Fanout 实战

Direct exchange（直连模式）

Topics exchange

#Topic 的介绍

Topic 匹配案例

---

生产者生产的消息从不会直接发送到队列，生产者只能将消息发送到交换机(exchange)

Exchanges 的类型：

​ 直接(direct), 主题(topic) ,标题(headers) , 扇出(fanout)

 

无名exchange：

第一个参数是交换机的名称。空字符串表示默认或无名称交换机：消息能路由发送到队列中其实是由 routingKey(bindingkey)绑定 key 指定的，如果它存在的话

 

绑定 bindings

binding 其实是 exchange 和 queue 之间的桥梁，它告诉我们 exchange 和那个队列进行了绑定关系

 

Fanout exchange

#Fanout 介绍

Fanout 这种类型非常简单。正如从名称中猜到的那样，它是将接收到的所有消息广播到它知道的 所有队列中。系统中默认有些 exchange 类型

Fanout 实战

①ReceiveLogs01 将接收到的消息打印在控制台

public class ReceiveLogs01 {
    //定义交换机的名字
  private static final String EXCHANGE_NAME = "logs";

    public static void main(String[] args) throws Exception {

        Channel channel= RabbitMQUtil.getChannel();
        //创建一个交换机
        channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.FANOUT);
        /**
         * 生成一个临时的队列 队列的名称是随机的
         * 当消费者断开和该队列的连接时 队列自动删除
         */
        String queueName = channel.queueDeclare().getQueue();
        //把该临时队列绑定我们的 exchange 其中 routingkey(也称之为 binding key)为空字符串
        channel.queueBind(queueName, EXCHANGE_NAME, "");
        System.out.println("等待接收消息,把接收到的消息打印在屏幕........... ");

        //发送回调
        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println("控制台打印接收到的消息" + message);
        };
        channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {});

    }
}

 

 

 ②ReceiveLogs02 把消息写出到文件

public class ReceiveLogs02 {
    private static final String EXCHANGE_NAME = "logs";

    public static void main(String[] args) throws Exception {

        Channel channel= RabbitMQUtil.getChannel();
        channel.exchangeDeclare(EXCHANGE_NAME, "fanout");
        /**
         * 生成一个临时的队列 队列的名称是随机的
         * 当消费者断开和该队列的连接时 队列自动删除
         */
        String queueName = channel.queueDeclare().getQueue();
        //把该临时队列绑定我们的 exchange 其中 routingkey(也称之为 binding key)为空字符串
        channel.queueBind(queueName, EXCHANGE_NAME, "");
        System.out.println("等待接收消息,把接收到的消息写到文件........... ");

        //发送回调
        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            File file = new File("D:\\test\\rabbitmq_info.txt");
            FileUtils.writeStringToFile(file,message,"UTF-8");
            System.out.println("数据写入文件成功");
        };
        channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {});

    }
}

③EmitLog 发送消息给两个消费者接收：

public class EmitLog {
    private static final String EXCHANGE_NAME = "logs";

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

        /**
         * 声明一个 exchange
         * 1.exchange 的名称
         * 2.exchange 的类型
         */
        channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.FANOUT);
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入信息");
        while (sc.hasNext()) {
            String message = sc.nextLine();
            //将消息发送给交换机，再有交换机绑定队列，在传递给队列
            channel.basicPublish(EXCHANGE_NAME, "", null, message.getBytes("UTF-8"));
            System.out.println("生产者发出消息" + message);
        }
    }
}

 

 

④启动运行

 

 ReceiveLogs01接收笑死

 ReceiveLogs02写入文件

 进入磁盘查看

 

Direct exchange（直连模式）

简单理解：需要满足条件才可接收，不满足的直接丢弃变成死信消息

 

#Direct 实战

①创建ReceiveLogsDirect01消费者

 

public class ReceiveLogsDirect01 {
    private static final String EXCHANGE_NAME = "direct_logs";

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

        String queueName = "disk";
        //队列声明
        channel.queueDeclare(queueName, false, false, false, null);
        //队列绑定
        channel.queueBind(queueName, EXCHANGE_NAME, "error");
        System.out.println("等待接收消息...");

        //发送回调
        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            message = "接收绑定键:" + delivery.getEnvelope().getRoutingKey() + ",消息:" + message;
            System.out.println("error 消息已经接收：\n" + message);
        };
        channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
        });
    }
}

 

② 创建ReceiveLogsDirect02消费者

public class ReceiveLogsDirect02 {
    private static final String EXCHANGE_NAME = "direct_logs";

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

        String queueName = "console";
        //队列声明
        channel.queueDeclare(queueName, false, false, false, null);
        //队列绑定
        channel.queueBind(queueName, EXCHANGE_NAME, "info");
        channel.queueBind(queueName, EXCHANGE_NAME, "warning");

        System.out.println("等待接收消息...");

        //发送回调
        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            message = "接收绑定键:" + delivery.getEnvelope().getRoutingKey() + ",消息:" + message;
            System.out.println("info和warning 消息已经接收：\n" + message);
        };
        channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
        });
    }
}

 ③EmitLogDirect生产者

public class EmitLogDirect {
    private static final String EXCHANGE_NAME = "direct_logs";

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

        //创建多个 bindingKey
        Map bindingKeyMap = new HashMap<>();
        bindingKeyMap.put("info", "普通 info 信息");
        bindingKeyMap.put("warning", "警告 warning 信息");
        bindingKeyMap.put("error", "错误 error 信息");
        //debug 没有消费这接收这个消息 所有就丢失了
        bindingKeyMap.put("debug", "调试 debug 信息");

        for (Map.Entry bindingKeyEntry : bindingKeyMap.entrySet()) {
            //获取 key value
            String bindingKey = bindingKeyEntry.getKey();
            String message = bindingKeyEntry.getValue();

            channel.basicPublish(EXCHANGE_NAME, bindingKey, null, message.getBytes("UTF-8"));
            System.out.println("生产者发出消息:" + message);
        }
    }
}

 

④启动运行

 

 ReceiveLogsDirect01接收消息

 

 ReceiveLogsDirect02接收消息

 

Topics exchange

#Topic 的介绍

发送到类型是 topic 交换机的消息的 routing_key 不能随意写，必须满足一定的要求，它必须是一个单词列表，以点号分隔开。这些单词可以是任意单词

在这个规则列表中，其中有两个替换符是大家需要注意的：

• *(星号)可以代替一个单词
• #(井号)可以替代零个或多个单词

Topic 匹配案例

①ReceiveLogsTopic01消费者

public class ReceiveLogsTopic01 {
    private static final String EXCHANGE_NAME = "topic_logs";

    public static void main(String[] args) throws Exception {
        Channel channel= RabbitMQUtil.getChannel();
        channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.TOPIC);
        //声明 Q1 队列与绑定关系
        String queueName = "Q1";
        //声明
        channel.queueDeclare(queueName, false, false, false, null);
        //绑定
        channel.queueBind(queueName, EXCHANGE_NAME, "*.orange.*");
        System.out.println("等待接收消息........... ");

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" 接收队列:" + queueName + " 绑定键:" + delivery.getEnvelope().getRoutingKey() + ",消息:" + message);
        };
        channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
        });
    }
}

 

②ReceiveLogsTopic02消费者

public class ReceiveLogsTopic02 {
    private static final String EXCHANGE_NAME = "topic_logs";

    public static void main(String[] args) throws Exception {
        Channel channel= RabbitMQUtil.getChannel();
        channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.TOPIC);
        //声明 Q2 队列与绑定关系
        String queueName = "Q2";
        //声明
        channel.queueDeclare(queueName, false, false, false, null);
        //绑定
        channel.queueBind(queueName, EXCHANGE_NAME, "*.*.rabbit");
        channel.queueBind(queueName, EXCHANGE_NAME, "lazy.#");

        System.out.println("等待接收消息........... ");

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" 接收队列:" + queueName + " 绑定键:" + delivery.getEnvelope().getRoutingKey() + ",消息:" + message);
        };
        channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
        });
    }
}

 

③EmitLogTopic生产者

public class EmitLogTopic {
    private static final String EXCHANGE_NAME = "topic_logs";

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

        /**
         * Q1-->绑定的是
         *      中间带 orange 带 3 个单词的字符串(*.orange.*)
         * Q2-->绑定的是
         *      最后一个单词是 rabbit 的 3 个单词(*.*.rabbit)
         *      第一个单词是 lazy 的多个单词(lazy.#)
         *
         */
        Map bindingKeyMap = new HashMap<>();
        bindingKeyMap.put("quick.orange.rabbit", "被队列 Q1Q2 接收到");
        bindingKeyMap.put("lazy.orange.elephant", "被队列 Q1Q2 接收到");
        bindingKeyMap.put("quick.orange.fox", "被队列 Q1 接收到");
        bindingKeyMap.put("lazy.brown.fox", "被队列 Q2 接收到");
        bindingKeyMap.put("lazy.pink.rabbit", "虽然满足两个绑定但只被队列 Q2 接收一次");
        bindingKeyMap.put("quick.brown.fox", "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", "是四个单词不匹配任何绑定会被丢弃");
        bindingKeyMap.put("lazy.orange.male.rabbit", "是四个单词但匹配 Q2");
        for (Map.Entry bindingKeyEntry : bindingKeyMap.entrySet()) {
            String bindingKey = bindingKeyEntry.getKey();
            String message = bindingKeyEntry.getValue();

            channel.basicPublish(EXCHANGE_NAME, bindingKey, null, message.getBytes("UTF-8"));
            System.out.println("生产者发出消息：" + message);
        }
    }
}

④启动运行

 ReceiveLogsTopic01接收消息

ReceiveLogsTopic0接收消息