• 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

    1.  
    2. public class ReceiveLogs01 {
    3.     //定义交换机的名字
    4.   private static final String EXCHANGE_NAME = "logs";
    5.  
    6.     public static void main(String[] args) throws Exception {
    7.  
    8.         Channel channel= RabbitMQUtil.getChannel();
    9.         //创建一个交换机
    10.         channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.FANOUT);
    11.         /**
    12.          * 生成一个临时的队列 队列的名称是随机的
    13.          * 当消费者断开和该队列的连接时 队列自动删除
    14.          */
    15.         String queueName = channel.queueDeclare().getQueue();
    16.         //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
    17.         channel.queueBind(queueName, EXCHANGE_NAME, "");
    18.         System.out.println("等待接收消息,把接收到的消息打印在屏幕........... ");
    19.  
    20.         //发送回调
    21.         DeliverCallback deliverCallback = (consumerTag, delivery) -> {
    22.             String message = new String(delivery.getBody(), "UTF-8");
    23.             System.out.println("控制台打印接收到的消息" + message);
    24.         };
    25.         channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {});
    26.  
    27.     }
    28. }

     

     

     ②ReceiveLogs02 把消息写出到文件

    1. public class ReceiveLogs02 {
    2.     private static final String EXCHANGE_NAME = "logs";
    3.  
    4.     public static void main(String[] args) throws Exception {
    5.  
    6.         Channel channel= RabbitMQUtil.getChannel();
    7.         channel.exchangeDeclare(EXCHANGE_NAME, "fanout");
    8.         /**
    9.          * 生成一个临时的队列 队列的名称是随机的
    10.          * 当消费者断开和该队列的连接时 队列自动删除
    11.          */
    12.         String queueName = channel.queueDeclare().getQueue();
    13.         //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
    14.         channel.queueBind(queueName, EXCHANGE_NAME, "");
    15.         System.out.println("等待接收消息,把接收到的消息写到文件........... ");
    16.  
    17.         //发送回调
    18.         DeliverCallback deliverCallback = (consumerTag, delivery) -> {
    19.             String message = new String(delivery.getBody(), "UTF-8");
    20.             File file = new File("D:\\test\\rabbitmq_info.txt");
    21.             FileUtils.writeStringToFile(file,message,"UTF-8");
    22.             System.out.println("数据写入文件成功");
    23.         };
    24.         channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {});
    25.  
    26.     }
    27. }

    ③EmitLog 发送消息给两个消费者接收：

    1. public class EmitLog {
    2.     private static final String EXCHANGE_NAME = "logs";
    3.  
    4.     public static void main(String[] args) throws Exception {
    5.         Channel channel= RabbitMQUtil.getChannel();
    6.  
    7.         /**
    8.          * 声明一个 exchange
    9.          * 1.exchange 的名称
    10.          * 2.exchange 的类型
    11.          */
    12.         channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.FANOUT);
    13.         Scanner sc = new Scanner(System.in);
    14.         System.out.println("请输入信息");
    15.         while (sc.hasNext()) {
    16.             String message = sc.nextLine();
    17.             //将消息发送给交换机，再有交换机绑定队列，在传递给队列
    18.             channel.basicPublish(EXCHANGE_NAME, "", null, message.getBytes("UTF-8"));
    19.             System.out.println("生产者发出消息" + message);
    20.         }
    21.     }
    22. }

     

     

    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

     

    1. public class ReceiveLogsDirect01 {
    2.     private static final String EXCHANGE_NAME = "direct_logs";
    3.  
    4.     public static void main(String[] args) throws Exception {
    5.         Channel channel= RabbitMQUtil.getChannel();
    6.         channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.DIRECT);
    7.  
    8.         String queueName = "disk";
    9.         //队列声明
    10.         channel.queueDeclare(queueName, false, false, false, null);
    11.         //队列绑定
    12.         channel.queueBind(queueName, EXCHANGE_NAME, "error");
    13.         System.out.println("等待接收消息...");
    14.  
    15.         //发送回调
    16.         DeliverCallback deliverCallback = (consumerTag, delivery) -> {
    17.             String message = new String(delivery.getBody(), "UTF-8");
    18.             message = "接收绑定键:" + delivery.getEnvelope().getRoutingKey() + ",消息:" + message;
    19.             System.out.println("error 消息已经接收：\n" + message);
    20.         };
    21.         channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
    22.         });
    23.     }
    24. }

     

    ② 创建ReceiveLogsDirect02消费者

    1. public class ReceiveLogsDirect02 {
    2.     private static final String EXCHANGE_NAME = "direct_logs";
    3.  
    4.     public static void main(String[] args) throws Exception {
    5.         Channel channel= RabbitMQUtil.getChannel();
    6.         channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.DIRECT);
    7.  
    8.         String queueName = "console";
    9.         //队列声明
    10.         channel.queueDeclare(queueName, false, false, false, null);
    11.         //队列绑定
    12.         channel.queueBind(queueName, EXCHANGE_NAME, "info");
    13.         channel.queueBind(queueName, EXCHANGE_NAME, "warning");
    14.  
    15.         System.out.println("等待接收消息...");
    16.  
    17.         //发送回调
    18.         DeliverCallback deliverCallback = (consumerTag, delivery) -> {
    19.             String message = new String(delivery.getBody(), "UTF-8");
    20.             message = "接收绑定键:" + delivery.getEnvelope().getRoutingKey() + ",消息:" + message;
    21.             System.out.println("info和warning 消息已经接收：\n" + message);
    22.         };
    23.         channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
    24.         });
    25.     }
    26. }

     ③EmitLogDirect生产者

    1.  
    2. public class EmitLogDirect {
    3.     private static final String EXCHANGE_NAME = "direct_logs";
    4.  
    5.     public static void main(String[] args) throws Exception {
    6.         Channel channel= RabbitMQUtil.getChannel();
    7.         channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.DIRECT);
    8.  
    9.         //创建多个 bindingKey
    10.         Map<String, String> bindingKeyMap = new HashMap<>();
    11.         bindingKeyMap.put("info", "普通 info 信息");
    12.         bindingKeyMap.put("warning", "警告 warning 信息");
    13.         bindingKeyMap.put("error", "错误 error 信息");
    14.         //debug 没有消费这接收这个消息 所有就丢失了
    15.         bindingKeyMap.put("debug", "调试 debug 信息");
    16.  
    17.         for (Map.Entry<String, String> bindingKeyEntry : bindingKeyMap.entrySet()) {
    18.             //获取 key value
    19.             String bindingKey = bindingKeyEntry.getKey();
    20.             String message = bindingKeyEntry.getValue();
    21.  
    22.             channel.basicPublish(EXCHANGE_NAME, bindingKey, null, message.getBytes("UTF-8"));
    23.             System.out.println("生产者发出消息:" + message);
    24.         }
    25.     }
    26. }

     

    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

    1. public class ReceiveLogsTopic01 {
    2.     private static final String EXCHANGE_NAME = "topic_logs";
    3.  
    4.     public static void main(String[] args) throws Exception {
    5.         Channel channel= RabbitMQUtil.getChannel();
    6.         channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.TOPIC);
    7.         //声明 Q1 队列与绑定关系
    8.         String queueName = "Q1";
    9.         //声明
    10.         channel.queueDeclare(queueName, false, false, false, null);
    11.         //绑定
    12.         channel.queueBind(queueName, EXCHANGE_NAME, "*.orange.*");
    13.         System.out.println("等待接收消息........... ");
    14.  
    15.         DeliverCallback deliverCallback = (consumerTag, delivery) -> {
    16.             String message = new String(delivery.getBody(), "UTF-8");
    17.             System.out.println(" 接收队列:" + queueName + " 绑定键:" + delivery.getEnvelope().getRoutingKey() + ",消息:" + message);
    18.         };
    19.         channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
    20.         });
    21.     }
    22. }

     

    ②ReceiveLogsTopic02消费者

    1. public class ReceiveLogsTopic02 {
    2.     private static final String EXCHANGE_NAME = "topic_logs";
    3.  
    4.     public static void main(String[] args) throws Exception {
    5.         Channel channel= RabbitMQUtil.getChannel();
    6.         channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.TOPIC);
    7.         //声明 Q2 队列与绑定关系
    8.         String queueName = "Q2";
    9.         //声明
    10.         channel.queueDeclare(queueName, false, false, false, null);
    11.         //绑定
    12.         channel.queueBind(queueName, EXCHANGE_NAME, "*.*.rabbit");
    13.         channel.queueBind(queueName, EXCHANGE_NAME, "lazy.#");
    14.  
    15.         System.out.println("等待接收消息........... ");
    16.  
    17.         DeliverCallback deliverCallback = (consumerTag, delivery) -> {
    18.             String message = new String(delivery.getBody(), "UTF-8");
    19.             System.out.println(" 接收队列:" + queueName + " 绑定键:" + delivery.getEnvelope().getRoutingKey() + ",消息:" + message);
    20.         };
    21.         channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
    22.         });
    23.     }
    24. }

     

    ③EmitLogTopic生产者

    1.  
    2. public class EmitLogTopic {
    3.     private static final String EXCHANGE_NAME = "topic_logs";
    4.  
    5.     public static void main(String[] args) throws Exception {
    6.         Channel channel= RabbitMQUtil.getChannel();
    7.         channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.TOPIC);
    8.  
    9.         /**
    10.          * Q1-->绑定的是
    11.          *      中间带 orange 带 3 个单词的字符串(*.orange.*)
    12.          * Q2-->绑定的是
    13.          *      最后一个单词是 rabbit 的 3 个单词(*.*.rabbit)
    14.          *      第一个单词是 lazy 的多个单词(lazy.#)
    15.          *
    16.          */
    17.         Map<String, String> bindingKeyMap = new HashMap<>();
    18.         bindingKeyMap.put("quick.orange.rabbit", "被队列 Q1Q2 接收到");
    19.         bindingKeyMap.put("lazy.orange.elephant", "被队列 Q1Q2 接收到");
    20.         bindingKeyMap.put("quick.orange.fox", "被队列 Q1 接收到");
    21.         bindingKeyMap.put("lazy.brown.fox", "被队列 Q2 接收到");
    22.         bindingKeyMap.put("lazy.pink.rabbit", "虽然满足两个绑定但只被队列 Q2 接收一次");
    23.         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");
    24.         bindingKeyMap.put("quick.orange.male.rabbit", "是四个单词不匹配任何绑定会被丢弃");
    25.         bindingKeyMap.put("lazy.orange.male.rabbit", "是四个单词但匹配 Q2");
    26.         for (Map.Entry<String, String> bindingKeyEntry : bindingKeyMap.entrySet()) {
    27.             String bindingKey = bindingKeyEntry.getKey();
    28.             String message = bindingKeyEntry.getValue();
    29.  
    30.             channel.basicPublish(EXCHANGE_NAME, bindingKey, null, message.getBytes("UTF-8"));
    31.             System.out.println("生产者发出消息：" + message);
    32.         }
    33.     }
    34. }

    ④启动运行

     ReceiveLogsTopic01接收消息

    ReceiveLogsTopic0接收消息

     

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  • 原文地址：https://blog.csdn.net/lu__lala/article/details/125456926