DirectExchange switch simple introduction demo

The source code is at the end of the article

Pre-learning knowledge

1. FanoutExchange switch code tutorial SpringAMQP Simple Getting Started demo​​​​​​​2

Students who know Fanout switches must know that when sending messages to Fanout switches, you only need to specify the name of the switch and the message to be sent, and you can specify multiple queues FanoutExchange switch code tutorial

 @Testpublic void testSendFanoutExchange() {// switch nameString exchangeName = "Declare FanoutExchange";// informationString message = "Test the FanoutExchange switch, please accept it!";rabbitTemplate.convertAndSend(exchangeName, "", message);}

The difference between the Direct switches we want to learn below is very similar to Fanout, But the only difference is that each Queue sets a BindingKey with Exchange, And you also need to specify the RoutingKey of the message when publishing the message

Let's demonstrate with code

 @RabbitListener(bindings = @QueueBinding(//queue namevalue = @Queue("direct.queue1"),// switch nameexchange = @Exchange(value = "direct", type = ExchangeTypes.DIRECT),//keykey = {"red", "blue"}))public void listenDirectQueue1(String msg){System.out.println("The consumer received the message of fanout.queue1: [" + msg + "]");}@RabbitListener(bindings = @QueueBinding(value = @Queue("direct.queue2"),exchange = @Exchange(value = "direct"),key = {"red", "yellow"}))public void listenDirectQueue2(String msg){System.out.println("The consumer received the message of fanout.queue1: [" + msg + "]");}

Case 1 The value of key is blue

 @Testpublic void testSendDirectExchange() {// switch nameString exchangeName = "direct";// informationString red = "hello, blue!";rabbitTemplate.convertAndSend(exchangeName, "blue", red);}

Run result:

Parse:

The reason is very simple "blue" is included in the key declared in our QueueBinding

Case 2 The key value is red

 @Testpublic void testSendDirectExchange() {// switch nameString exchangeName = "direct";// informationString red = "hello, red!";rabbitTemplate.convertAndSend(exchangeName, "red", red);}

Running result:
​​​​​​​Analysis:

We can see that this time the message was received by two queues at the same time. In the queues direct.queue1 and direct.queue2, the keys declared in QueueBinding also contain"red"

Source code project address:

Link: https://pan.baidu.com/s/1vnYVEPGO8B5XLCf9Xc67cA Extraction code: few9