Java Spring generator
Use your AsyncAPI definition to generate java code to subscribe and publish messages
Usage
AsyncAPI definitions
To have correctly generated code, your AsyncAPI file MUST define operationId
for every operation.
In order for the generator to know what names to use for some parameters it's necessary to make use of AsyncAPI specification bindings.
- Complete example for Kafka is here. Notice information about binding.
channels: event.lighting.measured: publish: bindings: kafka: groupId: my-group message: $ref: '#/components/messages/lightMeasured' subscribe: message: $ref: '#/components/messages/lightMeasured'
- Complete example for MQTT is here.
From the command-line interface (CLI)
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
Supported parameters
Name | Description | Required | Default |
---|---|---|---|
disableEqualsHashCode | Disable generation of equals and hashCode methods for model classes. | No | false |
inverseOperations | Generate an application that will publish messages to publish operation of channels and read messages from subscribe operation of channels. Literally this flag will simply swap publish and subscribe operations in the channels. This flag will be useful when you want to generate a code of mock for your main application. Be aware, generation could be incomplete and manual changes will be required e.g. if bindings are defined only for case of main application. |
No | false |
javaPackage | The Java package of the generated classes. Alternatively you can set the specification extension info.x-java-package . If both extension and parameter are used, parameter has more priority. |
No | com.asyncapi |
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 |
addTypeInfoHeader | Only for Kafka. Add type information to message header. | No | true |
connectionTimeout | Only for MQTT. This value, measured in seconds, defines the maximum time interval the client will wait for the network connection to the MQTT server to be established. The default timeout is 30 seconds. A value of 0 disables timeout processing meaning the client will wait until the network connection is made successfully or fails. | No | 30 |
disconnectionTimeout | Only for MQTT. The completion timeout in milliseconds when disconnecting. The default disconnect completion timeout is 5000 milliseconds. | No | 5000 |
completionTimeout | Only for MQTT. The completion timeout in milliseconds for operations. The default completion timeout is 30000 milliseconds. | No | 30000 |
asyncapiFileDir | Path where original AsyncAPI file will be stored. | No | src/main/resources/api/ |
Examples
The shortest possible syntax:
ag asyncapi.yaml @asyncapi/java-spring-template
Specify where to put the result and define poll timeout:
ag -o ./src asyncapi.yaml -p listenerPollTimeout=5000 @asyncapi/java-spring-template
If you don't have the AsyncAPI Generator installed, you can install it like this:
npm install -g @asyncapi/generator
Development
-
Clone the repository:
git clone https://github.com/asyncapi/java-spring-template cd java-spring-template
-
Make sure template has all the dependencies:
npm install
-
Install AsyncAPI Generator:
npm install -g @asyncapi/generator
-
Run generation:
# for MQTT protocol test with below ag tests/mocks/mqtt.yml ./ --output output # for Kafka protocol test with below ag tests/mocks/kafka.yml ./ --output output
-
Explore generated files in
output
directory
For local development, you need different variations of this command. First of all, you need to know about three important CLI flags:
--debug
enables the debug mode.--watch-template
enables a watcher of changes that you make in the template. It regenerates your template whenever it detects a change.--install
enforces reinstallation of the template.
Run it
Go to the root folder of the generated code and run this command (you need the JDK1.8):
./gradlew bootRun
Generated source contains RabbitMQ docker-compose. So you could use it to test amqp with:
docker-compose -f src/main/docker/rabbitmq.yml up -d
Missing features
See 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 protocol
amqp
could be out of date. Please have a look to application.yaml and AmqpConfig.java - tests for protocol
amqp
are not provided - add annotation to the model generation. Consider "@Valid", "@JsonProperty", "@Size", "@NotNull" e.t.c.
-
parameters
for topics are not supported -
server variables
are not entirely supported -
security schemas
are not supported -
traits
are not supported - Json serializer/deserializer 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.
Contributors ✨
Thanks goes to these wonderful people (emoji key):
Semen 📖 💻 |
Francesco Nobilia 👀 |
Amrut Prabhu 💻 |
This project follows the all-contributors specification. Contributions of any kind welcome!