Not a JSON Object Exception in Scala

Question

With reference to answer in following post: Find the maximum value from JSON data in Scala

I am very new to programming in Scala, and as one solution states in the mentioned post, I am testing following code:

import collection.immutable.IndexedSeq
import com.google.gson.Gson
import com.google.gson.JsonObject
import com.google.gson.JsonParser

case class wrapperObject(val json_string: Array[MyJsonObject])
case class MyJsonObject(val id:Int ,val price:Int)

object Demo {

    val gson = new Gson()
    def main(args: Array[String])={
    val json_string = scala.io.Source.fromFile("jsonData.txt").getLines.mkString
    //val json_string= """{"json_string":[{"id":1,"price":4629},{"id":2,"price":7126},{"id":3,"price":8862},{"id":4,"price":8999},{"id":5,"price":1095}]}"""
    val jsonStringAsObject= new JsonParser().parse(json_string).getAsJsonObject
    val objectThatYouCanPlayWith:wrapperObject = gson.fromJson(jsonStringAsObject, classOf[wrapperObject])
    var maxPrice:Int = 0
    for(i <- objectThatYouCanPlayWith.json_string if i.price>maxPrice) 
    {
        maxPrice=  i.price
    }
    println(maxPrice)
}
}

I am getting following error at line 15. java.lang.IllegalStateException: Not a JSON Object:

The contents of the JSON file are as follows:

[{ "id":978,"price":2513},
{ "id":979,"price":8942},
{ "id":980,"price":1268},
{ "id":981,"price":5452},
{ "id":982,"price":5585},
{ "id":983,"price":9542}]

Not sure as to why this error is appearing. Any help would be appreciated. Thanks.

Your file does not contain a valid json. Please share the contents of jsonData.txt, but I would just search online for a json formatter that will highlight your issue for you. — Dan Ciborowski - MSFT
– Dan Ciborowski - MSFT, Commented Dec 7, 2016 at 17:53
Edited the question with contents of the JSON file. I have searched and tried using GSON. — hshantanu
– hshantanu, Commented Dec 7, 2016 at 17:58
I think your code may have worked if you had used .getAsJsonArray instead of .getAsJsonObject — Dan Ciborowski - MSFT
– Dan Ciborowski - MSFT, Commented Dec 7, 2016 at 18:41

The_Tourist · Accepted Answer · 2016-12-07 18:23:23Z

1

Your JSON file is not valid JSON format. As per the logic you implemented with wrapperObject, your file should look like this:

{
    "json_string": [
        { "id":978,"price":2513},
        { "id":979,"price":8942},
        { "id":980,"price":1268},
        { "id":981,"price":5452},
        { "id":982,"price":5585},
        { "id":983,"price":9542}
    ]
}

which will then give the output 9542. Note that your commented out version of json_string is actually valid and the output would be 8999.

JSON format is an attribute-value pair, but your file only has value - which is Array[MyJsonObject]. As per your wrapperObject case class, json_string is the attribute, and it's needed for Gson to parse the data into an object of type wrapperObject.

edited Dec 7, 2016 at 18:23

answered Dec 7, 2016 at 18:01

The_Tourist

2,14818 silver badges22 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Not a JSON Object Exception in Scala

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related