关于java:消息中间件RabbitMQ二-RabbitMQ交换器类型与原生API的使用

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一. RabbitMQ 音讯解决
在上一节咱们讲到了 RabbitMQ 的简略架构，咱们先回顾一下 RabbitMQ 中音讯的流转流程，这个概念会在本节中应用到。

1. 生产者生产音讯后，会绑定一个路由键将音讯投递到交换器中
2. 队列通过路由键绑定到交换器
3. 交换器通过音讯的路由键去查找绑定在它下面的队列，通过不同的规定去匹配队列绑定的路由键，匹配胜利后将音讯路由到队列上，遍历所有队列后都没有匹配的音讯将无奈路由到队列
4. 消费者监听队列，一旦有音讯路由到队列，消费者就会从队列中取出音讯或者是 RabbitMQ 将音讯推送给消费者进行生产

下面的流程是在失常状况下的音讯解决流程，对于投递失败的音讯和生产失败的音讯，咱们会在后续的知识点中讲到

二. 交换器类型
不同类型的交换器有不同的路由键键匹配规定，咱们先来看看 RabbitMQ 中有哪几种交换器
1 Direct
只有当路由键齐全匹配时，才会将音讯投递到相应的队列中

2 Fanout
音讯播送到绑定的队列，即该类型的交换器不会依据路由键去匹配队列，只有有音讯投递到该交换器，它就会将音讯投递到所有绑定在该交换器上的队列

3 Topic
Topic 交换器能够应用通配符 (“*” 和 “#”) 使来自不同源头的音讯达到对立队列。”.”将路由键分为了几个标识符，” * “ 匹配 1 个，”#” 匹配一个或多个

eg：有四个队列，queue1 绑定路由键 ”usa.#”，queue2 绑定路由键 ”#.news”，queue3 绑定路由键 ”*.weather”，queue4 绑定路由键 ”europe.*”

四条音讯:message1 绑定的路由键为 ”usa.news”，message2 绑定的路由键为 ”usa.weather”，message3 绑定的路由键为 ”europe.news”，message4 绑定的路由键为 ”errope.weather”

路由后:
queue1 能收到音讯 message1，message2
queue2 能收到音讯 message1，message3
queue3 能收到音讯 message2，message4
queue4 能收到音讯 message3，message4

须要留神一点是，”*” 是匹配一个，”#” 匹配多个。若是音讯绑定路由键为 usa.weather.cloud，那么 ”usa.*” 无奈匹配该路由键，”usa.#” 能匹配，此时也能够应用 ”usa.*.*” 匹配

4 Headers
因为 headers 交换器根本不必，这里就不做解说

三. 应用 RabbitMQ 原生 API
应用 RabbitMQ 原生 API 来发送和生产音讯时，依照如下流程

生产者：
获取连贯工厂
ConnectionFactory factory = new ConnectionFactory();

新建连贯
public Connection newConnection();

创立信道
Channel createChannel();

申明交换器
Exchange.DeclareOk exchangeDeclare(String exchange, BuiltinExchangeType type)
args1 交换器名称，args2 交换器类型

发送音讯
void basicPublish(String exchange, String routingKey, boolean mandatory, BasicProperties props, byte[] body)
args1 交换器名，args2 路由键，args3 音讯无奈路由时的解决，为 true 时生产者能够通过回调函数获取音讯状态，args4 音讯属性，args5 音讯体

消费者:
获取连贯工厂
ConnectionFactory factory = new ConnectionFactory();

新建连贯
public Connection newConnection();

创立信道
Channel createChannel();

申明交换器
Exchange.DeclareOk exchangeDeclare(String exchange, BuiltinExchangeType type)
args1 交换器名称，args2 交换器类型

申明队列
Queue.DeclareOk queueDeclare(String queue, boolean durable, boolean exclusive, boolean autoDelete, Map<String, Object> arguments)
args1 队列名，arg2 是否长久化，args3 是否独占队列，args4 主动删除，args5 其余属性

队列绑定
Queue.BindOk queueBind(String queue, String exchange, String routingKey, Map<String, Object> arguments)
args1 队列名，args2 交换器名，args3 路由键，arg4 其余属性

音讯生产
String basicConsume(String queue, boolean autoAck, Consumer callback)
args1 队列名，args2 是否主动签收，args3 消费者

四. 应用不同的交换器实现音讯解决

  1. Direct Exchange

DirectProducer Demo

public class DirectProducer {

    public static final String EXCHANGE_NAME = "direct_exchange";

    public static final String ROUTING_KEY = "direct_key";

    public static void main(String[] args) throws Exception{
        // 创立连贯工厂
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("127.0.0.1");
        factory.setVirtualHost("/");

        // 新建连贯
        Connection connection = factory.newConnection();

        // 创立信道
        Channel channel = connection.createChannel();

        // 申明交换器
        channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.DIRECT);

        String msg = "hello rabbitmq";
        // 发送音讯
        channel.basicPublish(EXCHANGE_NAME, ROUTING_KEY,null, msg.getBytes());
        System.out.println("音讯投递实现，音讯:" + msg + ", 路由键:" + ROUTING_KEY);

        channel.close();
        connection.close();}
}

生产者端后果

DirectConsumer Demo

public class DirectConsumer {public static void main(String[] args) throws Exception{
        // 创立连贯工厂
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("127.0.0.1");
        connectionFactory.setVirtualHost("/");

        // 创立连贯
        Connection connection = connectionFactory.newConnection();

        // 创立信道
        Channel channel = connection.createChannel();

        // 申明交换器
        channel.exchangeDeclare(DirectProducer.EXCHANGE_NAME, BuiltinExchangeType.DIRECT);

        String queueName = "direct_queue";

        // 申明队列
        channel.queueDeclare(queueName, false, false, false, null);

        // 将队列绑定到交换器
        channel.queueBind(queueName, DirectProducer.EXCHANGE_NAME, DirectProducer.ROUTING_KEY);

        // 申明消费者
        Consumer consumer = new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {String msg = new String(body, "UTF-8");
                System.out.println("收到的音讯:" + msg + ", 路由键:" + envelope.getRoutingKey());
            }
        };

        // 消费者生产指定队列的音讯
        channel.basicConsume(queueName, true, consumer);
    }
}

生产端后果：

  1. Fanout Exchange

FanoutProducer Demo

public class FanoutProducer {

    // 交换器
    public static final String EXCHANGE_NAME = "fanout_exchange";

    // 路由键
    public static final String ROUTING_KEY = "fanout_key";

    public static void main(String[] args) throws Exception{
        // 获取连贯工厂
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setVirtualHost("/");
        connectionFactory.setHost("127.0.0.1");
        connectionFactory.setPort(5672);

        // 获取连贯
        Connection connection = connectionFactory.newConnection();

        // 申明信道
        Channel channel = connection.createChannel();

        // 申明交换器
        channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.FANOUT);

        // 发送音讯
        String msg = "hello rabbitmq";
        channel.basicPublish(FanoutProducer.EXCHANGE_NAME, ROUTING_KEY, null, msg.getBytes());
        System.out.println("发送音讯:" + msg + "，路由键:" + ROUTING_KEY);

        channel.close();
        connection.close();}
}

生产端后果：

FanoutConsumer Demo

public class FanoutConsumer {public static void main(String[] args) throws Exception{
        // 创立连贯工厂
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("127.0.0.1");
        connectionFactory.setVirtualHost("/");

        // 创立连贯
        Connection connection = connectionFactory.newConnection();

        // 创立信道
        Channel channel = connection.createChannel();

        // 申明交换器
        channel.exchangeDeclare(FanoutProducer.EXCHANGE_NAME, BuiltinExchangeType.FANOUT);

        // 队列
        String[] queueNames = {"queue1", "queue2", "queue3"};

        // 路由键
        String[] routingKey = {"fanout_key", "fanout_key1", "fanout_key2"};

        // 别离应用不同的路由键申明不同的队列
        for (int i = 0; i < 3; i++){channel.queueDeclare(queueNames[i], false, false, false, null);
            channel.queueBind(queueNames[i], FanoutProducer.EXCHANGE_NAME, routingKey[i]);

            // 生产音讯
            channel.basicConsume(queueNames[i], true, new DefaultConsumer(channel){
                @Override
                public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {String msg = new String(body, "UTF-8");
                    System.out.println("音讯：" + msg + "，路由键：" + envelope.getRoutingKey());
                }
            });
        }
    }
}

生产端后果：

  1. Topic Exchange

TopicProducer Demo

public class TopicProducer {

    // 交换器
    public static final String EXCHANGE_NAME = "topic_exchange";

    public static void main(String[] args) throws Exception{
        // 创立连贯工厂
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("127.0.0.1");
        factory.setVirtualHost("/");

        // 新建连贯
        Connection connection = factory.newConnection();

        // 创立信道
        Channel channel = connection.createChannel();

        // 申明交换器
        channel.exchangeDeclare(TopicProducer.EXCHANGE_NAME, BuiltinExchangeType.TOPIC);

        // 发送音讯
        String msg = "hello rabbitmq";
        String[] routingKey = {"topic.key1", "topic.key2", "topic.key2.test"};

        for (int i = 0; i < 3; i++){channel.basicPublish(TopicProducer.EXCHANGE_NAME, routingKey[i], null, msg.getBytes());
            System.out.println("发送音讯:" + msg + ", 路由键:" + routingKey[i]);
        }

        channel.close();
        connection.close();}
}

生产端后果：

TopicConsumer Demo

public class TopicConsumer {public static void main(String[] args) throws Exception{
        // 创立连贯工厂
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("127.0.0.1");
        factory.setVirtualHost("/");

        // 新建连贯
        Connection connection = factory.newConnection();

        // 创立信道
        Channel channel = connection.createChannel();

        // 申明交换器
        channel.exchangeDeclare(TopicProducer.EXCHANGE_NAME, BuiltinExchangeType.TOPIC);

        String queueName = "topic_queue";

        // 申明队列
        channel.queueDeclare(queueName, false, false, false, null);

        // 队列绑定
        channel.queueBind(queueName, TopicProducer.EXCHANGE_NAME, "topic.*");

        // 音讯生产
        channel.basicConsume(queueName, true, new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {String msg = new String(body, "UTF-8");
                System.out.println("音讯:" + msg + ", 路由键:" + envelope.getRoutingKey());
            }
        });
    }
}

生产端后果：

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java
发表至： java
2020-08-15
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