@rost5000/asyncapi-java-micronaut-template

Java Micronaut Generator

Use your AsyncAPI definition to generate java (code based on Micronaut framework) to subscribe and publish messages.

This project is based on java-spring-template

Micronaut Documentation

• User Guide
• API Reference
• Micronaut Guides

Additional features in the project:

• Micronaut AOT documentation
• Micronaut Serialization Jackson Core documentation
• Micronaut JMS documentation

Usage

AsyncAPI definitions

To have correctly generated code, your AsyncAPI file MUST define operationId for every operation and jmsConnectionFactory should be set.

In order for the generator to know what names to use for some parameters it's necessary to make use of AsyncAPI specification (JMS bindings)[https://github.com/asyncapi/bindings/tree/master/jms].

Complete example of JMS usage here

From the command-line interface (CLI)

  Usage: ag [options] <asyncapi> https://github.com/rost5000/asyncapi-java-micronaut-template.git

  Options:

    -V, --version                 output the version number
    -o, --output <outputDir>       directory where to put the generated files (defaults to current directory)
    -p, --param <name=value>       additional param to pass to templates
    -h, --help                    output usage information

Example command:

 asyncapi generate fromTemplate jms.yaml https://github.com/rost5000/asyncapi-java-micronaut-template.git

Name	Description	Required	Default
defaultImplementaion	Generate implementation of the subscriber interfaces by default.	false	true
javaPackage	The Java package of the generated classes. Alternatively you can set the specification extension info.x-java-package	false	com.asyncapi
generateConsumers	Tell generator to generate consumers	false	true
generateProducers	Tell generator to generate producers	false	true

Micronaut specific properties

You can specify serviceExecutor property for generating service executor for queue listener. For example:

servers:
  production:
# ...
    bindings:
# ...
      properties:
        - name: serviceExecutor
          value: serviceExecutor

It is needed sometimes for micronaut Queue annotation.

Declare channel from environment variables

Sometimes you need to specify channel from environment variables. You can just do it by specifed destination property in `bindigns. For example:

channels:
  WhoCaresChannelName:
    bindings:
      jms:
        destination: ${JMS_CHANNEL:OrOtherChannelName}
# ...

All String will put from destination to Queue#value. And resulted code looks like:

@Queue(
  value = "${JMS_CHANNEL:OrOtherChannelName}"
)

You can specify exactly in channel or publish, for example:

channels:
  NoName:
    publish:
      bindings:
        jms:
          destination: ${JMS_CHANNEL_PUBLISHER}
# ...
    subscribe:
      bindings:
        jms:
          destination: ${JMS_CHANNEL_SUBSCRIBER}

Additional links

• AsyncAPI
• How to generate code from AsyncAPI CLI
• JMS specification bindings