Default values from Retrofit Server response are being shown as null

Question

I am calling an api which will gives me some values and some not. So i have given some variables default values. But even when i am not getting them from server , they are being shown as null in log and app is crashing.

Here is the model class:

data class FeedbackData(

    var questionNumber: Int = 0,
    var imageUri: Uri? = null,

    @SerializedName("id") val id: Int,
    @SerializedName("question") val question: String? = null,
    @SerializedName("answer") var answer: Answer = Answer()

)

data class Answer(

    @SerializedName("description") var description: String = "",
    @SerializedName("image") var image: String = ""
)

if you see i have given answer a default object (default initialization) incase server doesnt send it. My requirement is that if server sends it i should have it,if not then i should be able to write that answer object. But i am getting null pointer exception when i am trying to access that answer object.

Here is the log

 E/xoxo: received list: [FeedbackData(questionNumber=0, imageUri=null, id=1, question=How was the event?, answer=null), FeedbackData(questionNumber=0, imageUri=null, id=2, question=Did you face any issue?, answer=null)

And here is the server response:

{"id":1,"question":"How was the event?"},
{"id":2,"question":"Did you face any issue?"}

Answer 1

So for now i have given value to all the fields above, to id also which did not have default value and now it seems to work. It is seeming like a cheat solution but its working.

Answer 2

Based on the code you have shown, you are initializing

var answer: Answer = Answer()

But since server is returning null, it is replacing the default Answer with null value. One possible solution could be to provide getter method, something on these lines

var name: answer : Answer
        get() = field?:Answer()

Note: Verify syntax.

Answer 3

If you are using progaurd, keep your model classes away from obfuscation. Use keepclassmembers in progaurd.