Micronaut Codegen

OpenAPI code generator for Micronaut.

Include in your pom.xml:

<plugin>
 <groupId>org.openapitools</groupId>
 <artifactId>openapi-generator-maven-plugin</artifactId>
 <version>${version.org.openapitools.generator}</version>
 <executions>
  <execution>
   <goals>
    <goal>generate</goal>
   </goals>
  </execution>
 </executions>
 <configuration>
  <generatorName>micronaut</generatorName>
  <output>${project.build.directory}</output>
  <inputSpec>src/resources//openapi/spec.yaml</inputSpec>
  <packageName>changeMe</packageName>
 </configuration>
 <dependencies>
  <dependency>
   <groupId>io.kokuwa.micronaut</groupId>
   <artifactId>micronaut-openapi-codegen</artifactId>
   <version>${version.io.kokuwa.micronaut.codegen}</version>
  </dependency>
 </dependencies>
</plugin>

Features

generate api interfaces (see declarative client)
generate model objects with fluent and property accessors
generate interfaces for api tests based on method name and return code
generate client interfaces with micronaut clientId
add validation annotations
support for One-Of interfaces
support for additional properties with composed schemas
generate example instances of the model-objects

Config options

clientId: id for generated clients (if no client id is provided no interface will be generated)
introspected: add @io.micronaut.core.annotation.Introspected to models (default true)
dateTimeRelaxed: add type registrar for relaxed time converter (default true)
useBeanValidation: generate validation annotations (default true)
useGenericResponse: return generic container or specific model, e.g. Model vs. HttpResponse<Model> (default true)
useOptional: optional parameters are generated as java.util.Optional (default true)
openApiNullable: add container JsonNullable to model objects that are nullable (default true)
supportAsync: use reactivex return types, see Reactive HTTP Request Processing
pagable: generate provider for pagable (default false)
generateExamples: generate example objects for the model, based on example and default values (default false)
generateAuthentication: generate Àuthentication into controller interfaces if responsecode 401 is present (default false)

For examples see integration tests.

Null handling and default values

Jackson Inclusions:

required=true & nullable=false: JsonInclude.ALWAYS
required=true & nullable=true: JsonInclude.ALWAYS
required=false & nullable=false: JsonInclude.NON_ABSENT
required=false & nullable=true: JsonInclude.NON_NULL

Container (array/map):

required=true & nullable=false: empty containers are set as default value
required=true & nullable=true: containers have no default value
required=false & nullable=false: containers have no default value
required=false & nullable=true: containers have no default value

If jacksonDatabindNullable=true is configured always JsonNullable.undefined() is set.

Do not forget to add the dependency to pom.xml:

<dependency>
 <groupId>org.openapitools</groupId>
 <artifactId>jackson-databind-nullable</artifactId>
 <version>0.2.2</version>
</dependency>

And register Jackson Module:

@Factory
public class ApplicationFactory {

 @Singleton
 JsonNullableModule jsonNullableModule() {
  return new JsonNullableModule();
 }
}

Not supported

no project (e.g. pom.xml) is generated, only interfaces to implement
no support for java <11

Build & Release

Test

Run single test:

mvn verify -Dinvoker.parallelThreads=1 -Dinvoker.streamLogs=true -Dinvoker.test=test-api

Dependency updates

Display dependency updates:

mvn versions:display-property-updates -U

Update dependencies:

mvn versions:update-properties

Release locally

Run:

mvn release:prepare release:perform release:clean -B

Denis-26 / micronaut-openapi-codegen