Purpose of this Generator is to ease development of Spring Cloud Streams microservices by supporting defining them in AsyncAPI. The problem was decomposed into the following parts:
- Generate Project Structure Project structure and build is taken care of by the Spring Initializr project, and thus was reused.
- Generate POJO's based off of the input/output messages Since AsyncAPI supports defining the message payloads as JSON Schema, this enables code generators to generate the POJOs which represent these data structures. Since I am not a code generator wizard, I leveraged dentrassi's java generator and commented out a few lines so that it only generated the message payload objects. That is why this code contains those packages.
- Generate SCS application
In order to generate the SCS Application, the associated java class must have the proper annotations specifying whether it is a source, sink or processor. In addition the method must so that it has a method signature which either sink, source or processor (
@EnableBinding) and matches the method to the appropriate@InboundChannelAdapter,@StreamListeneror@Output. This enables the user to simply add their business logic versus having to understand the mechanics of SCS - Generate Application.YAML - binds the application to the runtime though binder interface
The
Application.yamlfile purpose is to map the INPUTS/OUTPUTS to the underling binding implementation. In this case, this generator works with Solace's but could easily be extended to support others.
How to run it:
Run:
mvn clean install
Run the generated jar file:
java -jar AsyncAPI-SpringCloudStreams-Generator-0.0.1-SNAPSHOT-spring-boot.jar --p="com.solace.spring.cloud.streams.test" --java --jar --mvn --sbv=2.1.4.RELEASE --jv=1.8 --cu=solace-cloud-client --cp=XXXXXXXXXXXXXXXX --mvpn=msgvpn No-Yelling-Processor.yaml
| Option | Description |
|---|---|
| -p | source code root package |
| --java | means to use java |
| --jar | means to package as a jar |
| --mvn | means to make it a maven build |
| --sbv | the spring boot version to use |
| --jv | the java version to use |
| --cu | the solace client username |
| --cp | the solace client password |
| --mvpn | the solace message vpn to connect to |
the last argument is the AsyncAPI file (2.0.0-rc1) to generate into code. That argument is not optional