Use your AsyncAPI definition to generate java code to subscribe and publish messages
In order for the generator to know what names to use for some methods it's necessary to make use of AsyncAPI specification bindings. here is an example of how to use it:
channels:
event.lighting.measured:
publish:
bindings:
kafka:
groupId: my-group
message:
$ref: '#/components/messages/lightMeasured'
subscribe:
message:
$ref: '#/components/messages/lightMeasured'here is a complete example
asyncapi: '2.0.0'
info:
title: Streetlights API
version: '1.0.0'
description: |
The Smartylighting Streetlights API allows you
to remotely manage the city lights.
license:
name: Apache 2.0
url: 'https://www.apache.org/licenses/LICENSE-2.0'
servers:
production:
url: api.streetlights.smartylighting.com:{port}
protocol: mqtt
variables:
port:
default: '1883'
enum:
- '1883'
- '8883'
channels:
event.lighting.measured:
publish:
bindings:
kafka:
groupId: my-group
message:
$ref: '#/components/messages/lightMeasured'
subscribe:
message:
$ref: '#/components/messages/lightMeasured'
components:
messages:
lightMeasured:
summary: Inform about environmental lighting conditions for a particular streetlight.
payload:
$ref: "#/components/schemas/lightMeasuredPayload"
schemas:
lightMeasuredPayload:
type: object
properties:
lumens:
type: integer
minimum: 0
description: Light intensity measured in lumens.
sentAt:
$ref: "#/components/schemas/sentAt"
sentAt:
type: string
format: date-time
description: Date and time when the message was sent. Usage: ag [options] <asyncapi> @asyncapi/java-spring-template
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| Name | Description | Required | Default |
|---|---|---|---|
| listenerPollTimeout | Only for Kafka. Timeout in ms to use when polling the consumer. | No | 3000 |
| listenerConcurrency | Only for Kafka. Number of threads to run in the listener containers. | No | 3 |
The shortest possible syntax:
ag asyncapi.yaml @asyncapi/java-spring-templateSpecify where to put the result and define poll timeout:
ag -o ./src asyncapi.yaml -p listenerPollTimeout=5000 @asyncapi/java-spring-templateIf you don't have the AsyncAPI Generator installed, you can install it like this:
npm install -g @asyncapi/generator
Go to the root folder of the generated code and run this command (you need the JDK1.8):
./gradlew bootRunGenerated source contains RabbitMQ docker-compose. So you could use it to test amqp with:
docker-compose -f src/main/docker/rabbitmq.yml up -dSee the list of features that are still missing in the component:
- support of Kafka is done based on clear "spring-kafka" library without integration like for mqtt or amqp
- generated code for protocols mqtt and amqp could be out of date. Please have a look to application.yaml and AmqpConfig.java, MqttConfig.java
- tests are not provided
- add annotation to the model generation. Consider "@Valid", "@JsonProperty", "@Size", "@NotNull" e.t.c.
-
parametersfor topics are not supported -
server variablesare not entirely supported -
security schemasare not supported -
traitsare not supported - Json serializer/desirializer is used always, without taking into account real
content type - client side generation mode (in general just flip subscribe and publish channels)
- template generation of docker-compose depending on protocol of server, now the rabbitmq is hardcoded
If you want to help us develop them, feel free to contribute.