目錄
前言
來了解RabbitMQ一個重要的概念:Exchange交換機
1. Exchange概念
Exchange:接收消息,並根據路由鍵轉發消息所綁定的隊列。
- 藍色框:客戶端發送消息至交換機,通過路由鍵路由至指定的隊列。
- 黃色框:交換機和隊列通過路由鍵有一個綁定的關係。
- 綠色框:消費端通過監聽隊列來接收消息。
2. 交換機屬性
- Name:交換機名稱
- Type:交換機類型——direct、topic、fanout、headers、sharding(此篇不講)
- Durability:是否需要持久化,true爲持久化
- Auto Delete:當最後一個綁定到Exchange上的隊列刪除後,自動刪除該Exchange
- Internal:當前Exchange是否用於RabbitMQ內部使用,默認爲false
- Arguments:擴展參數,用於擴展AMQP協議自定製化使用
3. Direct Exchange(直連)
- 所有發送到Direct Exchange的消息被轉發到RouteKey中指定的Queue
- 注意:Direct模式可以使用RabbitMQ自帶的Exchange:default Exchange,所以不需要將Exchange進行任何綁定(binding)操作,消息傳遞時,RouteKey必須完全匹配纔會被隊列接收,否則該消息會被拋棄。
- 重點:routing key與隊列queues 的key保持一致,即可以路由到對應的queue中。
3.1 Direct Exchange(直連)代碼演示
我們來看下大概步驟:
- ConnectionFacorty:獲取連接工廠
- Connection:一個連接
- Channel:數據通信信道,可發送和接收消息
- Queue:具體的消息存儲隊列
- Producer & Consumer 生產者和消費者
- 這個連接工廠需要配置一些相應的信息,例如: RabbitMQ節點的地址,端口號,VirtualHost等等。
- Channel是我們RabbitMQ所有消息進行交互的關鍵。
生產端:
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class Producer4DirectExchange {
public static void main(String[] args) throws Exception {
//1 創建ConnectionFactory
ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setHost("192.168.11.76");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
//2 創建Connection
Connection connection = connectionFactory.newConnection();
//3 創建Channel
Channel channel = connection.createChannel();
//4 聲明
String exchangeName = "test_direct_exchange";
String routingKey = "test.direct111";
//5 發送
String msg = "Hello World RabbitMQ 4 Direct Exchange Message 111 ... ";
channel.basicPublish(exchangeName, routingKey , null , msg.getBytes());
}
}
消費端:
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;
import com.rabbitmq.client.QueueingConsumer.Delivery;
public class Consumer4DirectExchange {
public static void main(String[] args) throws Exception {
ConnectionFactory connectionFactory = new ConnectionFactory() ;
connectionFactory.setHost("192.168.11.76");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
connectionFactory.setAutomaticRecoveryEnabled(true);
connectionFactory.setNetworkRecoveryInterval(3000);
Connection connection = connectionFactory.newConnection();
Channel channel = connection.createChannel();
//4 聲明
String exchangeName = "test_direct_exchange";
String exchangeType = "direct";
String queueName = "test_direct_queue";
String routingKey = "test.direct";
//表示聲明瞭一個交換機
channel.exchangeDeclare(exchangeName, exchangeType, true, false, false, null);
//表示聲明瞭一個隊列
channel.queueDeclare(queueName, false, false, false, null);
//建立一個綁定關係:
channel.queueBind(queueName, exchangeName, routingKey);
//durable 是否持久化消息
QueueingConsumer consumer = new QueueingConsumer(channel);
//參數:隊列名稱、是否自動ACK、Consumer
channel.basicConsume(queueName, true, consumer);
//循環獲取消息
while(true){
//獲取消息,如果沒有消息,這一步將會一直阻塞
Delivery delivery = consumer.nextDelivery();
String msg = new String(delivery.getBody());
System.out.println("收到消息:" + msg);
}
}
}
queueDeclare 說明
channel.queueDeclare(queueName, true, false, false, null);
- 第一個參數:queuename:隊列的名稱
- 第二個參數:durable 是否持久化。true消息會持久化到本地,保證重啓服務後消息不會丟失
- 第三個參數:exclusive :表示獨佔方式,設置爲true 在某些情景下有必要,例如:順序消費。表示只有一個channel可以去監聽,其他channel都不能夠監聽。目的就是爲了保證順序消費。
- 第四個參數:autoDelete:隊列如果與Exchange未綁定,則自動刪除
- 第五個參數:arguments:擴展參數
測試結果:
注意需要routingKey保持一致。可以自己嘗試修改routingkey,是否能收到消息。
4. Topic Exchange
- 所有發送到Topic Exchange的消息被轉發到所有管線RouteKey中指定Topic的Queue上
- Exchange將RouteKey和某Topic進行模糊匹配,此時隊列需要綁定一個Topic
在一堆消息中,每個不同的隊列只關心自己需要的消息。
4.1 Topic Exchange代碼演示
Topic Exchange生產端:
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class Producer4TopicExchange {
public static void main(String[] args) throws Exception {
//1 創建ConnectionFactory
ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setHost("192.168.11.76");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
//2 創建Connection
Connection connection = connectionFactory.newConnection();
//3 創建Channel
Channel channel = connection.createChannel();
//4 聲明
String exchangeName = "test_topic_exchange";
String routingKey1 = "user.save";
String routingKey2 = "user.update";
String routingKey3 = "user.delete.abc";
//5 發送
String msg = "Hello World RabbitMQ 4 Topic Exchange Message ...";
channel.basicPublish(exchangeName, routingKey1 , null , msg.getBytes());
channel.basicPublish(exchangeName, routingKey2 , null , msg.getBytes());
channel.basicPublish(exchangeName, routingKey3 , null , msg.getBytes());
channel.close();
connection.close();
}
}
Topic Exchange消費端:
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;
import com.rabbitmq.client.QueueingConsumer.Delivery;
public class Consumer4TopicExchange {
public static void main(String[] args) throws Exception {
ConnectionFactory connectionFactory = new ConnectionFactory() ;
connectionFactory.setHost("192.168.11.76");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
connectionFactory.setAutomaticRecoveryEnabled(true);
connectionFactory.setNetworkRecoveryInterval(3000);
Connection connection = connectionFactory.newConnection();
Channel channel = connection.createChannel();
//4 聲明
String exchangeName = "test_topic_exchange";
String exchangeType = "topic";
String queueName = "test_topic_queue";
//String routingKey = "user.*";
String routingKey = "user.*";
// 1 聲明交換機
channel.exchangeDeclare(exchangeName, exchangeType, true, false, false, null);
// 2 聲明隊列
channel.queueDeclare(queueName, false, false, false, null);
// 3 建立交換機和隊列的綁定關係:
channel.queueBind(queueName, exchangeName, routingKey);
//durable 是否持久化消息
QueueingConsumer consumer = new QueueingConsumer(channel);
//參數:隊列名稱、是否自動ACK、Consumer
channel.basicConsume(queueName, true, consumer);
//循環獲取消息
while(true){
//獲取消息,如果沒有消息,這一步將會一直阻塞
Delivery delivery = consumer.nextDelivery();
String msg = new String(delivery.getBody());
System.out.println("收到消息:" + msg);
}
}
}
Topic Exchange測試結果:
注意一個問題:需要進行解綁
5. Fanout Exchange
- 不處理路由鍵,只需要簡單的將隊裏綁定到交換機上
- 發送到交換機的消息都會被轉發到與該交換機綁定的所有隊列上
- Fanout交換機轉發消息是最快的
5.1 Fanout Exchange代碼演示
Fanout Exchange生產端:
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class Producer4FanoutExchange {
public static void main(String[] args) throws Exception {
//1 創建ConnectionFactory
ConnectionFactory connectionFactory = new ConnectionFactory();
connectionFactory.setHost("192.168.11.76");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
//2 創建Connection
Connection connection = connectionFactory.newConnection();
//3 創建Channel
Channel channel = connection.createChannel();
//4 聲明
String exchangeName = "test_fanout_exchange";
//5 發送
for(int i = 0; i < 10; i ++) {
String msg = "Hello World RabbitMQ 4 FANOUT Exchange Message ...";
channel.basicPublish(exchangeName, "", null , msg.getBytes());
}
channel.close();
connection.close();
}
}
Fanout Exchange消費端:
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;
import com.rabbitmq.client.QueueingConsumer.Delivery;
public class Consumer4FanoutExchange {
public static void main(String[] args) throws Exception {
ConnectionFactory connectionFactory = new ConnectionFactory() ;
connectionFactory.setHost("192.168.11.76");
connectionFactory.setPort(5672);
connectionFactory.setVirtualHost("/");
connectionFactory.setAutomaticRecoveryEnabled(true);
connectionFactory.setNetworkRecoveryInterval(3000);
Connection connection = connectionFactory.newConnection();
Channel channel = connection.createChannel();
//4 聲明
String exchangeName = "test_fanout_exchange";
String exchangeType = "fanout";
String queueName = "test_fanout_queue";
String routingKey = ""; //不設置路由鍵
channel.exchangeDeclare(exchangeName, exchangeType, true, false, false, null);
channel.queueDeclare(queueName, false, false, false, null);
channel.queueBind(queueName, exchangeName, routingKey);
//durable 是否持久化消息
QueueingConsumer consumer = new QueueingConsumer(channel);
//參數:隊列名稱、是否自動ACK、Consumer
channel.basicConsume(queueName, true, consumer);
//循環獲取消息
while(true){
//獲取消息,如果沒有消息,這一步將會一直阻塞
Delivery delivery = consumer.nextDelivery();
String msg = new String(delivery.getBody());
System.out.println("收到消息:" + msg);
}
}
}
6. Exchange交換機其他屬性
6.1 Bingding —— 綁定
- Exchange和Exchange、Queue之間的連接關係
- Bingding可以包含RoutingKey或者參數
6.2 Queue——消息隊列
- 消息隊列,實際存儲消息數據
- Durability:是否持久化,Durable:是 ,Transient:否
- Auto delete:如選yes,代表當最後一個監聽被移除之後,該Queue會自動被刪除。
6.3 Message——消息
- 服務器與應用程序之間傳送的數據
- 本質上就是一段數據,由Properties和Payload(Body)組成
- 常用屬性:delivery mode、headers(自定義屬性)
6.4 其他屬性
- content_type、content_encoding、priority
- correlation_id、reply_to、expiration、message_id
- timestamp、type、user_id、app_id、cluster_id
6.5 Virtual Host虛擬主機
- 虛擬地址,用於進行邏輯隔離,最上層的消息路由
- 一個Virtual Host裏面可以有若干個Exchange和Queue
- 同一個Virtual Host裏面不能有相同名稱的Exchange或Queue