WuHuaJi0/rabbitmq-example

rabbitmq example by java

Rabbitmq-example

Use simple code to demonstrate how to use rabbitmq.

Run rabbitmq by Docker.

To keep it simple, we can quickly run rabbitmq by docker use the following command:

docker run -it --rm --name rabbitmq -p 5672:5672 -p 15672:15672 rabbitmq:3-management

Then the rabbitmq will start and listen on the 5672 port, and it also provider a web dashboard host on localhost:15672

Require the rabbitmq client

In java, in order to communicate with rabbitmq, you need to require the rabbitmq client to you code, which is already included in the pom.xml file.

<dependency>
    <groupId>com.rabbitmq</groupId>
    <artifactId>amqp-client</artifactId>
    <version>5.12.0</version>
</dependency>

The code structure

There are serial sub package in src/main/java, each of these represented a use case in rabbitmq. I will list below

hello

This package shows how the Producer and Consumer connect to the rabbitmq server, send or receive message from queue.

Workqueue

The work queue model means there is one Producer send message to a queue, and have two or more Consumer listen to the queue. Each message could have been received only once.

It is useful in the distributed system. We may deploy many Consumer in servers.

The code in this package have one producer and two consumer, the message from producer will send to only one consumer.

Publish/Subscribe

In this model, a message from Producer will send to the exchanger which the type is fanout, then the exchanger will deliver the message to queues which had been bind.

In this example, we first declare a fanout exchange and two queue, then bind them together. Now we just need specify the exchanger and no long need specify the queue name when we send a message from Producer.

Routing

In the Publish/Subscribe model, we are able to broadcast a message to many receivers. In the Routing model, we are able to send a message to subset of queues by specify the RoutingKey.

For example, we may want to send the error message a queue, and the warning/debug/info message to another queue.

The different with Publish/Subscribe model is that we need create a direct type of Exchanger, then bind the queue and exchanger with a RoutingKey.

When a message has been sent from producer, we not only need specify the Exchanger but specify the RoutingKey as well.

Topic

In the Topic model, we create an exchanger which the type is Topic.

//to be implemented.