Is there a way to check applicationContextPath on check config command?

[Innokentiy Struchkov]

Hi! I'm upgrading an old server to newer version of Dropwizard (1.x.x to 2.1.0) and other dependencies too. Now I have to explicitly check if user set the only correct applicationContextPath in server section of configuration file. Is there a way to do this in our Configuration implementation in constructor code (or within init block in Kotlin) or bootstrap initialization?

[Jochen Schalanda]

Hi,

You could (mis-) use Hibernate Validator for this and add a validation method with @AssertTrue to your configuration file in which you check the applicationContextPath.

@AssertTrue
public boolean validateApplicationContextPath() {
return server.getApplicationContextPath().equals("…“);
}

Cheers,
Jochen

[Innokentiy Struchkov]

Hi, Jochen!

Thanks for the advice, it does work! But I had to use a bit different approach with custom class annotation, like:

My configuration class (all code below in Kotlin):

@CheckApplicationContextPath

class MyConfiguration(

  val project: String,

  val env: String,

  ...

) : io.dropwizard:Configuration()

CheckApplicationContextPath.kt:

@Target(AnnotationTarget.CLASS)
@Retention(AnnotationRetention.RUNTIME)
@Constraint(validatedBy = [ApplicationContextPathValidator::class])
annotation class CheckApplicationContextPath(
  val message: String = "Please correct applicationContextPath in the config file",
  val groups: Array<KClass<*>> = [],
  val payload: Array<KClass<out Payload>> = []
)

ApplicationContextPathValidator.kt:

class ApplicationContextPathValidator : ConstraintValidator<CheckApplicationContextPath,  MyConfiguration > {
   override fun isValid(value: MyConfiguration , context: ConstraintValidatorContext): Boolean {

     val applicationContextPath = (value.serverFactory as SimpleServerFactory).applicationContextPath
     println("Config's applicationContextPath is $applicationContextPath")
     return applicationContextPath == "/myCorrectApplicationContextPath "
   }
}

Thanks again,
Innokentiy