IllegalArgumentException: Parameter specified as n

问题:

I'm getting the following runtime error:

 checkParameterIsNotNull, parameter oneClickTokens
    at com.info.app.fragments.Fragment_Payment_Profile$fetchMerchantHashes$1.onPostExecute(Fragment_Payment_Profile.kt:0)
    at com.info.app.fragments.Fragment_Payment_Profile$fetchMerchantHashes$1.onPostExecute(Fragment_Payment_Profile.kt:1543)

Here's my code:

 private fun fetchMerchantHashes(intent: Intent) {
    // now make the api call.
    val postParams = "merchant_key=$key&user_credentials=$var1"
    val baseActivityIntent = intent
    object : AsyncTask<Void, Void, HashMap<String, String>>() {

        override fun doInBackground(vararg params: Void): HashMap<String, String>? {
                ...
        }

        override fun onPostExecute(oneClickTokens: HashMap<String, String>) {
            super.onPostExecute(oneClickTokens)
            ...

        }
    }.execute()
}

It seems that the function call seems to be invalid. However, I don't know how to fix this problem. Is there anything Kotlin specific I've missed?

回答1:

The exception is pretty clear: you're passing null for the parameter.

By default all variables and parameters in Kotlin are non-null. If you want to pass null parameter to the method you should add ? to it's type, for example:

fun fetchMerchantHashes(intent: Intent?)

For more information: null-safety.

回答2:

In my case this error warned about probable passing a null as a parameter. Two ways of correction.

1. Change a type of parameter in corresponding place. If it is received from Java, add @NonNull annotation to a variable definition.
2. Add !! to a parameter of the method.