七种模式介绍与应用场景
简单模式(Hello World)
做最简单的事情,一个生产者对应一个消费者,RabbitMQ相当于一个消息代理,负责将A的消息转发给B
应用场景: 将发送的电子邮件放到消息队列,然后邮件服务在队列中获取邮件并发送给收件人
工作队列模式(Work queues)
在多个消费者之间分配任务(竞争的消费者模式),一个生产者对应多个消费者,一般适用于执行资源密集型任务,单个消费者处理不过来,需要多个消费者进行处理
应用场景: 一个订单的处理需要10s,有多个订单可以同时放到消息队列,然后让多个消费者同时处理,这样就是并行了,而不是单个消费者的串行情况
订阅模式(Publish/Subscribe)
一次向许多消费者发送消息,一个生产者发送的消息会被多个消费者获取,也就是将消息将广播到所有的消费者中。
应用场景: 更新商品库存后需要通知多个缓存和多个数据库,这里的结构应该是:
- 一个fanout类型交换机扇出两个个消息队列,分别为缓存消息队列、数据库消息队列
- 一个缓存消息队列对应着多个缓存消费者
- 一个数据库消息队列对应着多个数据库消费者
路由模式(Routing)
有选择地(Routing key)接收消息,发送消息到交换机并且要指定路由key ,消费者将队列绑定到交换机时需要指定路由key,仅消费指定路由key的消息
应用场景: 如在商品库存中增加了1台iphone12,iphone12促销活动消费者指定routing key为iphone12,只有此促销活动会接收到消息,其它促销活动不关心也不会消费此routing key的消息
主题模式(Topics)
根据主题(Topics)来接收消息,将路由key和某模式进行匹配,此时队列需要绑定在一个模式上,#
匹配一个词或多个词,*
只匹配一个词。
应用场景: 同上,iphone促销活动可以接收主题为iphone的消息,如iphone12、iphone13等
远程过程调用(RPC)
如果我们需要在远程计算机上运行功能并等待结果就可以使用RPC,具体流程可以看图。应用场景:需要等待接口返回数据,如订单支付
发布者确认(Publisher Confirms)
与发布者进行可靠的发布确认,发布者确认是RabbitMQ扩展,可以实现可靠的发布。在通道上启用发布者确认后,RabbitMQ将异步确认发送者发布的消息,这意味着它们已在服务器端处理。
应用场景: 对于消息可靠性要求较高,比如钱包扣款
代码演示
代码中没有对后面两种模式演示,有兴趣可以自己研究
简单模式
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import java.io.IOException; import java.util.concurrent.TimeoutException; public class Sender { private final static String QUEUE_NAME = "simple_queue"; public static void main(String[] args) throws IOException, TimeoutException { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); factory.setPort(5672); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); // 声明队列 // queue:队列名 // durable:是否持久化 // exclusive:是否排外 即只允许该channel访问该队列 一般等于true的话用于一个队列只能有一个消费者来消费的场景 // autoDelete:是否自动删除 消费完删除 // arguments:其他属性 channel.queueDeclare(QUEUE_NAME, false, false, false, null); //消息内容 String message = "simplest mode message"; channel.basicPublish("", QUEUE_NAME, null, message.getBytes()); System.out.println("[x]Sent '" + message + "'"); //最后关闭通关和连接 channel.close(); connection.close(); } }
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import com.rabbitmq.client.DeliverCallback; import java.io.IOException; import java.util.concurrent.TimeoutException; public class Receiver { private final static String QUEUE_NAME = "simplest_queue"; public static void main(String[] args) throws IOException, InterruptedException, TimeoutException { // 获取连接 ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); factory.setPort(5672); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.queueDeclare(QUEUE_NAME, false, false, false, null); DeliverCallback deliverCallback = (consumerTag, delivery) -> { String message = new String(delivery.getBody(), "UTF-8"); System.out.println(" [x] Received '" + delivery.getEnvelope().getRoutingKey() + "':'" + message + "'"); }; channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> { }); } }
工作队列模式
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import com.rabbitmq.client.DeliverCallback; import java.io.IOException; import java.util.concurrent.TimeoutException; public class Receiver1 { private final static String QUEUE_NAME = "queue_work"; public static void main(String[] args) throws IOException, InterruptedException, TimeoutException { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); factory.setPort(5672); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.queueDeclare(QUEUE_NAME, false, false, false, null); // 同一时刻服务器只会发送一条消息给消费者 channel.basicQos(1); DeliverCallback deliverCallback = (consumerTag, delivery) -> { String message = new String(delivery.getBody(), "UTF-8"); System.out.println(" [x] Received '" + delivery.getEnvelope().getRoutingKey() + "':'" + message + "'"); }; channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> { }); } }
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import com.rabbitmq.client.DeliverCallback; import java.io.IOException; import java.util.concurrent.TimeoutException; public class Receiver2 { private final static String QUEUE_NAME = "queue_work"; public static void main(String[] args) throws IOException, InterruptedException, TimeoutException { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); factory.setPort(5672); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.queueDeclare(QUEUE_NAME, false, false, false, null); // 同一时刻服务器只会发送一条消息给消费者 channel.basicQos(1); DeliverCallback deliverCallback = (consumerTag, delivery) -> { String message = new String(delivery.getBody(), "UTF-8"); System.out.println(" [x] Received '" + delivery.getEnvelope().getRoutingKey() + "':'" + message + "'"); }; channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> { }); } }
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import java.io.IOException; import java.util.concurrent.TimeoutException; public class Sender { private final static String QUEUE_NAME = "queue_work"; public static void main(String[] args) throws IOException, InterruptedException, TimeoutException { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); factory.setPort(5672); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); // 声明队列 channel.queueDeclare(QUEUE_NAME, false, false, false, null); for (int i = 0; i < 100; i++) { String message = "work mode message" + i; channel.basicPublish("", QUEUE_NAME, null, message.getBytes()); System.out.println("[x] Sent '" + message + "'"); Thread.sleep(i * 10); } channel.close(); connection.close(); } }
发布订阅模式
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import com.rabbitmq.client.DeliverCallback; public class Receive1 { private static final String EXCHANGE_NAME = "logs"; public static void main(String[] argv) throws Exception { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.exchangeDeclare(EXCHANGE_NAME, "fanout"); String queueName = channel.queueDeclare().getQueue(); channel.queueBind(queueName, EXCHANGE_NAME, ""); System.out.println(" [*] Waiting for messages. To exit press CTRL+C"); // 订阅消息的回调函数 DeliverCallback deliverCallback = (consumerTag, delivery) -> { String message = new String(delivery.getBody(), "UTF-8"); System.out.println(" [x] Received '" + message + "'"); }; // 消费者,有消息时出发订阅回调函数 channel.basicConsume(queueName, true, deliverCallback, consumerTag -> { }); } }
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import com.rabbitmq.client.DeliverCallback; public class Receive2 { private static final String EXCHANGE_NAME = "logs"; public static void main(String[] argv) throws Exception { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.exchangeDeclare(EXCHANGE_NAME, "fanout"); String queueName = channel.queueDeclare().getQueue(); channel.queueBind(queueName, EXCHANGE_NAME, ""); System.out.println(" [*] Waiting for messages. To exit press CTRL+C"); // 订阅消息的回调函数 DeliverCallback deliverCallback = (consumerTag, delivery) -> { String message = new String(delivery.getBody(), "UTF-8"); System.out.println(" [x] Received2 '" + message + "'"); }; // 消费者,有消息时出发订阅回调函数 channel.basicConsume(queueName, true, deliverCallback, consumerTag -> { }); } }
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; public class Sender { private static final String EXCHANGE_NAME = "logs"; public static void main(String[] argv) throws Exception { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.exchangeDeclare(EXCHANGE_NAME, "fanout"); String message = "publish subscribe message"; channel.basicPublish(EXCHANGE_NAME, "", null, message.getBytes("UTF-8")); System.out.println(" [x] Sent '" + message + "'"); channel.close(); connection.close(); } }
路由模式
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import com.rabbitmq.client.DeliverCallback; import java.io.IOException; import java.util.concurrent.TimeoutException; public class Receiver1 { private final static String QUEUE_NAME = "queue_routing"; private final static String EXCHANGE_NAME = "exchange_direct"; public static void main(String[] args) throws IOException, TimeoutException { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); factory.setPort(5672); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.queueDeclare(QUEUE_NAME, false, false, false, null); // 指定路由的key,接收key和key2 channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "key"); channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "key2"); channel.basicQos(1); DeliverCallback deliverCallback = (consumerTag, delivery) -> { String message = new String(delivery.getBody(), "UTF-8"); System.out.println(" [x] Received '" + delivery.getEnvelope().getRoutingKey() + "':'" + message + "'"); }; channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> { }); } }
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import com.rabbitmq.client.DeliverCallback; import java.io.IOException; import java.util.concurrent.TimeoutException; public class Receiver2 { private final static String QUEUE_NAME = "queue_routing2"; private final static String EXCHANGE_NAME = "exchange_direct"; public static void main(String[] args) throws IOException, TimeoutException { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); factory.setPort(5672); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.queueDeclare(QUEUE_NAME, false, false, false, null); // 仅接收key2 channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "key2"); channel.basicQos(1); DeliverCallback deliverCallback = (consumerTag, delivery) -> { String message = new String(delivery.getBody(), "UTF-8"); System.out.println(" [x] Received '" + delivery.getEnvelope().getRoutingKey() + "':'" + message + "'"); }; channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> { }); } }
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import java.io.IOException; import java.util.concurrent.TimeoutException; public class Sender { private final static String EXCHANGE_NAME = "exchange_direct"; private final static String EXCHANGE_TYPE = "direct"; public static void main(String[] args) throws IOException, TimeoutException { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); factory.setPort(5672); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); // 交换机声明 channel.exchangeDeclare(EXCHANGE_NAME, EXCHANGE_TYPE); // 只有routingKey相同的才会消费 String message = "routing mode message"; channel.basicPublish(EXCHANGE_NAME, "key2", null, message.getBytes()); System.out.println("[x] Sent '" + message + "'"); // channel.basicPublish(EXCHANGE_NAME, "key", null, message.getBytes()); // System.out.println("[x] Sent '" + message + "'"); channel.close(); connection.close(); } }
主题模式
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import com.rabbitmq.client.DeliverCallback; import java.io.IOException; import java.util.concurrent.TimeoutException; public class Receiver1 { private final static String QUEUE_NAME = "queue_topic"; private final static String EXCHANGE_NAME = "exchange_topic"; public static void main(String[] args) throws IOException, InterruptedException, TimeoutException { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); factory.setPort(5672); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.queueDeclare(QUEUE_NAME, false, false, false, null); // 可以接收key.1 channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "key.*"); channel.basicQos(1); DeliverCallback deliverCallback = (consumerTag, delivery) -> { String message = new String(delivery.getBody(), "UTF-8"); System.out.println(" [x] Received '" + delivery.getEnvelope().getRoutingKey() + "':'" + message + "'"); }; channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> { }); } }
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import com.rabbitmq.client.DeliverCallback; import java.io.IOException; import java.util.concurrent.TimeoutException; public class Receiver2 { private final static String QUEUE_NAME = "queue_topic2"; private final static String EXCHANGE_NAME = "exchange_topic"; private final static String EXCHANGE_TYPE = "topic"; public static void main(String[] args) throws IOException, InterruptedException, TimeoutException { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); factory.setPort(5672); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.queueDeclare(QUEUE_NAME, false, false, false, null); // *号代表单个单词,可以接收key.1 channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "*.*"); // #号代表多个单词,可以接收key.1.2 channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "*.#"); channel.basicQos(1); DeliverCallback deliverCallback = (consumerTag, delivery) -> { String message = new String(delivery.getBody(), "UTF-8"); System.out.println(" [x] Received '" + delivery.getEnvelope().getRoutingKey() + "':'" + message + "'"); }; channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> { }); } }
import com.rabbitmq.client.Channel; import com.rabbitmq.client.Connection; import com.rabbitmq.client.ConnectionFactory; import java.io.IOException; import java.util.concurrent.TimeoutException; public class Sender { private final static String EXCHANGE_NAME = "exchange_topic"; private final static String EXCHANGE_TYPE = "topic"; public static void main(String[] args) throws IOException, TimeoutException { ConnectionFactory factory = new ConnectionFactory(); factory.setHost("localhost"); factory.setPort(5672); Connection connection = factory.newConnection(); Channel channel = connection.createChannel(); channel.exchangeDeclare(EXCHANGE_NAME, EXCHANGE_TYPE); String message = "topics model message with key.1"; channel.basicPublish(EXCHANGE_NAME, "key.1", null, message.getBytes()); System.out.println("[x] Sent '" + message + "'"); String message2 = "topics model message with key.1.2"; channel.basicPublish(EXCHANGE_NAME, "key.1.2", null, message2.getBytes()); System.out.println("[x] Sent '" + message2 + "'"); channel.close(); connection.close(); } }
四种交换机介绍
- 直连交换机(Direct exchange): 具有路由功能的交换机,绑定到此交换机的时候需要指定一个routing_key,交换机发送消息的时候需要routing_key,会将消息发送道对应的队列
- 扇形交换机(Fanout exchange): 广播消息到所有队列,没有任何处理,速度最快
-
主题交换机(Topic exchange): 在直连交换机基础上增加模式匹配,也就是对routing_key进行模式匹配,
*
代表一个单词,#
代表多个单词 - 首部交换机(Headers exchange): 忽略routing_key,使用Headers信息(一个Hash的数据结构)进行匹配,优势在于可以有更多更灵活的匹配规则
总结
这么多种队列模式中都有其应用场景,大家可以根据应用场景示例中进行选择