RabbitMQ的工作模式之五主题（Topic）模式

RabbitMQ的工作模式之五主题（Topic）模式

发布订阅模式下，生产者与Topic类型的交换机打交道，由交换机将消息发送给对应绑定的队列，同时可以指定路由key，作为筛选的条件，同时可以进行模糊匹配。

导入依赖

<!--RabbitMQ的依赖-->
<dependency>
  <groupId>com.rabbitmq</groupId>
  <artifactId>amqp-client</artifactId>
  <version>5.7.3</version>
</dependency>

首先创建工具类，用以生成连接，避免重复书写此段代码

public class RabbitMQUtil {
    private static ConnectionFactory factory = new ConnectionFactory();
    static{
        //用户名
        factory.setUsername("hello");
        //密码
        factory.setPassword("123456");
        //虚拟机
        factory.setVirtualHost("/myhost");
        //IP地址,运行rabbitmq组件的主机ip地址
        factory.setHost("192.168.31.14");
        //端口
        factory.setPort(5672);
    }

    public static Connection getConnection(){
        Connection connection = null;
        try {
            connection = factory.newConnection();
            return  connection;
        } catch (IOException e) {
            e.printStackTrace();
        } catch (TimeoutException e) {
            e.printStackTrace();
        }
        return null;
    }
}

生产者

public class Producer {
    public static void main(String[] args) throws IOException, TimeoutException {
        //获取连接
        Connection connection = RabbitMQUtil.getConnection();
        //创建通道
        Channel channel = connection.createChannel();
        /**
         * 声明交换机
         * 参数1：交换机名称
         * 参数2：交换机类型：fanout、direct、topic、headers
         */
        channel.exchangeDeclare("topic_exchange", BuiltinExchangeType.TOPIC);
        Map<String,String> map = new HashMap<>();
        map.put("001","重庆");
        map.put("002","成都");
        map.put("003","北京");
        map.put("004","乌鲁木齐");
        for (String key : map.keySet()) {
            // 参数2：路由key就是 数据筛选的条件
            channel.basicPublish("topic_exchange",key,null,map.get(key).getBytes());
        }
        channel.close();
        connection.close();
    }
}

消费者

public class Customer1{
    public static void main(String[] args) throws IOException {
        //获取连接
        Connection connection = RabbitMQUtil.getConnection();
        //创建通道
        final Channel channel =connection.createChannel();
        //声明队列
        channel.queueDeclare("queue1",false,false,false,null);
        //绑定交换机和队列，设置路由key
        channel.queueBind("queue1","topic_exchange","001");
        channel.queueBind("queue1","topic_exchange","002");
        //签收消息:false表示手动编程的方式签收
        channel.basicConsume("queue1",false,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("customer1接收到的消息："+new String(body));
                //签收
                channel.basicAck(envelope.getDeliveryTag(),false);
            }
        });
    }
}

public class Customer2{
    public static void main(String[] args) throws IOException {
        Connection connection = RabbitMQUtil.getConnection();
        final Channel channel =connection.createChannel();
        channel.queueDeclare("queue2",false,false,false,null);
        //匹配所有
        channel.queueBind("queue2","topic_exchange","*");
        channel.basicConsume("queue2",false,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("customer2接收到的消息："+new String(body));
                channel.basicAck(envelope.getDeliveryTag(),false);
            }
        });
    }
}

注：生产者发送消息至交换机，交换机按照key分配给相应队列，这里测试时若先运行消费者端需要确保交换机被创建，故需要在消费者端声明交换机，此时生产者端不需要声明交换机，当然，如果先运行生产者端，则需要在生产者端先声明交换机，此时消费者端可以不用声明交换机，总之躯体情况具体分析，灵活运用，当然为了省事，可以一律声明。