Tutorials

Step by step, in order, each one ending with something that runs.

The guide explains how a thing works and why it is that way. These are the other shape: start with an empty project, finish with a service you can point at a broker.

1	Your first message	A service that publishes and consumes, and the management UI showing both	15 min
2	Declaring the topology	Exchanges, queues, bindings, and the deployment where the broker is provisioned by somebody else	20 min
3	When the handler fails	The retry ladder, dead letters, and why `Thread.sleep` in a consumer is expensive	25 min
4	Health and metrics	Actuator, Prometheus, and three graphs worth having on day one	20 min
5	Testing it	A fast test with no Docker, and an integration test with a real broker	25 min

Each builds on the one before. Nothing is left as an exercise.

Before you start

A JDK 17 or newer, Maven, and Docker for the broker.

curl https://start.spring.io/starter.zip \
  -d dependencies=web,actuator \
  -d type=maven-project \
  -d javaVersion=17 \
  -d groupId=com.example \
  -d artifactId=orders \
  -d name=orders \
  -d packageName=com.example.orders \
  -o orders.zip
unzip orders.zip -d orders
cd orders

Then add the AceMQ repository and starter to pom.xml:

<repositories>
  <repository>
    <id>acemq</id>
    <url>https://acemq-company.github.io/maven/</url>
  </repository>
</repositories>

<dependency>
  <groupId>org.acemq</groupId>
  <artifactId>acemq-spring-boot-starter</artifactId>
  <version>0.3.1</version>
</dependency>

The broker

docker run -d --name rabbit \
  -p 5672:5672 -p 15672:15672 \
  rabbitmq:4-management

Management UI at http://localhost:15672, guest/guest. Keep it open — every tutorial here has something to look at on it.

When you are done:

docker rm -f rabbit