Error message not showing from Spring ResponseStatusException

A little discovery I found recently. My error messages are not showing as intended.

@PostMapping
@ResponseStatus(HttpStatus.CREATED)
fun createAccount(@RequestBody account: Account): Account {
    if(accountService.existAccount(account.id))
        throw ResponseStatusException(HttpStatus.CONFLICT, "Account - ${account.id} already exists")

    return try{
        accountService.saveAccount(account)

    } catch (e: Exception) {
        throw ResponseStatusException(HttpStatus.BAD_REQUEST, "Invalid account - ${account.id}")
    }
}

The result is

{
    "timestamp": "2021-12-16T01:52:23.099+00:00",
    "status": 409,
    "error": "Conflict",
    "path": "/accounts"
}

My error message - Account - ${account.id} already exists doesn’t show up as intended.

So turns out that since Spring 2.3, error messages will not show by default, in order to reduce risks of leaking client information. (Source)[https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.3-Release-Notes#changes-to-the-default-error-pages-content].

So in order to make the error message appear again, the following line is to be included in the application.properties file - server.error.include-message=always. In case the application.properties file isn’t created yet, do create it in src\main\resources.

So after restarting, I will get the error message I wanted.

{
    "timestamp": "2021-12-16T01:58:27.722+00:00",
    "status": 409,
    "error": "Conflict",
    "message": "Account - CASH already exists",
    "path": "/accounts"
}