javalin-openapi does not work when controller class has more than one member

Actual behavior (the bug) I have a simple controller I’d like to generate documentation for:

App Setup:

fun main() {
    Javalin.create {
        it.registerPlugin(getConfiguredOpenApiPlugin())
        it.defaultContentType = "application/json"
    }.routes {
        post("user", MyController::createUser)
    }.start(7001)
}

fun getConfiguredOpenApiPlugin() = OpenApiPlugin(
    OpenApiOptions(
        Info().apply {
            version("1.0")
            description("User API")
        }
    ).apply {
        path("/swagger-docs")
        swagger(SwaggerOptions("/swagger-ui"))
    }
)

Controller:

data class User(
    val id: Int,
    val name: String,
    val email: String
)

object MyController {

    @OpenApi(
        operationId = "myOperation",
        description = "my description",
        requestBody = OpenApiRequestBody(content = [OpenApiContent(from = User::class)], required = true),
        responses = [OpenApiResponse(status = "200", content = [OpenApiContent(from = User::class)])]
    )
    fun createUser(ctx: Context) {
        ctx.result("done")
    }
}

This works as expected, and swagger-docs generates a schema for the User which is tied to the endpoint definition. However, if I add another function or even just a val to MyController, the annotation isn’t processed correctly and there is no schema, api definition, etc. Eg:

object MyController {

    val myProperty = "property"

    ... rest the same
}

Expected behavior I expect the generation to still work if my controller has other members.

To Reproduce Copy code above.

Additional context Consuming these dependencies:

    implementation("io.javalin:javalin:4.6.4")
    implementation("io.javalin:javalin-openapi:4.6.4")

[dzikoysk]

Built-in OpenApi module has dozen of issues:

• https://github.com/javalin/javalin/issues/1296

The one you’re reporting is probably another effect of those two:

• https://github.com/javalin/javalin/issues/1185
• https://github.com/javalin/javalin/issues/1193

There’s no fix tbh for all those issues, that’s why I’ve ended up with custom openapi implementation that will officially replace current module in Javalin 5.x. It’s also built on top of the annotation processor, not reflections:

• https://github.com/javalin/javalin-openapi

You can also use earlier version of this plugin for Javalin 4.x:

• https://github.com/javalin/javalin-openapi/tree/4.x

Plugin works properly and it’s relatively easy to extend, example of production ready code:

• https://github.com/dzikoysk/reposilite/blob/main/reposilite-backend/src/main/kotlin/com/reposilite/token/infrastructure/AccessTokenApiEndpoints.kt
• https://maven.reposilite.com/openapi
• https://maven.reposilite.com/swagger

All of that is generated by the new integration, so I think you can give it a try and report some missing features in its repository. Ofc plugin also works with Java:

• https://github.com/javalin/javalin-openapi/blob/main/openapi-test/src/main/java/io/javalin/openapi/plugin/test/JavalinTest.java

Keep in mind that API in 5.x has been slightly improved, so setup might be a little bit different. Take a look on 4.x branch for valid description.

[dzikoysk]

Reposilite 3.x I’ve linked you above with examples is already based on top of Javalin 5.x and it works well in production for quite a lof of people. The only disadvantage is that your project may randomly stop compiling in case of some breaking cosmetic changes, but overall I think it’s worth to give it a try, you’ll get access to latest features and you don’t really have to care about migration from 4.x in the future. In case of any issues you can always address it here in a new thread or ask on Javalin’s Discord server.