java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column

Question

im learning parcing and got a problem trying to make it happen. found a lot of similar questions and more solutions but nothing helped me

thats my json

{
  "firstName": "name",
  "lastName": "last",
  "resistances": {
    "a1": 1,
    "a2": 2,
    "a3": 3,
    "a4": 4
  }
}

Player.class

class Player implements Serializable{

    String firstName;
    String lastName;
    int[] resistances;

    public Player(String firstName, String lastName, int[] resistances) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.resistances = resistances;
    }
}

and how i try to parce

Gson gson = new Gson();
Player player = gson.fromJson("test.json", Player.class);

SOS

For "resistances" to be an array it should be: "resistances": [ 1, 2, 3, 4 ] so the error message is because it is finding the string "a1" — karora
– karora, Commented Feb 17, 2018 at 20:33

Crispert · Accepted Answer · 2018-02-17 20:30:40Z

1

fromJson(String, Class) parses the String itself, in your case test.json, not the file it represents. You need to create a Reader from the file you are trying to parse and pass it as first argument.

If test.json is in the external storage:

String fpath = Environment.getExternalStorageDirectory() + "/path/to/test.json";
 try {
        FileReader fr = new FileReader(fpath));
        gson.fromJson(fr, Player.class);
} catch (Exception e1) {
        e1.printStackTrace();
}

edited Feb 17, 2018 at 20:30

answered Feb 17, 2018 at 20:04

Crispert

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4 Comments

Crispert Over a year ago

I would have done this from the beginning, but it depends on the location of your file. If test.json is in the raw resource folder you can use new InputStreamReader(getResources().openRawResource(R.raw.test)) (the extension is ignored). If it's on the sd card, the answer is a bit longer.

Wiggle Over a year ago

thank you very much! its working! one more question - what is the difference between putting .json file is assets folder or raw ?

Crispert Over a year ago

Here is an explanation stackoverflow.com/questions/9563373/…

Wiggle Over a year ago

tyvm again! can i give you +karma ? :D

Charlie · Accepted Answer · 2018-02-17 20:08:23Z

1

Your JSON "resistances" object should look like this for your parsing code to work:

{
  "firstName": "name",
  "lastName": "last",
  "resistances": [
    1, 2, 3, 4
  ]
}

Or, change the resistances variable in Java to a Map. Look here for a previous answer - GSON can parse a dictionary JSON object to a Map.

class Player implements Serializable {

    String firstName;
    String lastName;
    Map<String, Integer> resistances;

    public Player(String firstName, String lastName, Map<String, Integer> resistances) {
        this.firstName   = firstName;
        this.lastName    = lastName;
        this.resistances = resistances;
    }
}

edited Feb 17, 2018 at 20:08

answered Feb 17, 2018 at 20:02

Charlie

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