Trying to read 2D array from Json to Android

Question

I have a problem reading my Json document because I want to read a 2d array looking like this:

"map" : [ ["PARED", "PARED", "PARED", "PARED", "PARED" , "PARED" , "PARED" , "PARED" , "PARED" , "PARED"], ["PARED" , "SNOWMAN" , "ESPACIO" , "PARED" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "PUERTA"], ["PARED" , "ESPACIO" , "SOL" , "PARED" , "PARED" , "PARED" , "ESPACIO" , "PARED" , "ESPACIO" , "PARED"], ["PARED" , "ESPACIO" , "PARED" , "PARED" , "SOL" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "PARED"], ["PARED" , "ESPACIO" , "PARED" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "SOL" , "ESPACIO" , "PARED" , "PARED"], ["PARED" , "ESPACIO" , "PARED" , "PARED" , "ESPACIO" , "PARED" , "PARED" , "ESPACIO" , "PARED" , "PARED"], ["PARED" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "PARED" , "SOL" , "ESPACIO" , "ESPACIO" , "PARED"], ["PARED" , "SOL" , "PARED" , "ESPACIO" , "PARED" , "PARED" , "ESPACIO" , "ESPACIO" , "SOL" , "PARED"], ["PARED" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "ESPACIO" , "PARED" , "ESPACIO" , "PARED"], ["PARED" , "PARED" , "PARED" , "PARED" , "PARED" , "PARED" , "PARED" , "PARED" , "PARED" , "PARED"] ]

And convert it to a "String [][] mapa;" array in Android Studio, but I don't know how to read and cast it.

I really apreciate your help.

EDIT: I tried something like this, but I don't know how to continue:

mapObject.getJSONArray("map")

EDIT2 something like that?:

JSONArray mapatest = mapObject.getJSONArray("map");

            String[][] innerArray = null;

            for(int t = 0; t < mapatest.getCount(); t++){

                innerArray[t] = mapatest.getJSONArray(t);

                for(int k = 0; k < innerArray.getCount(); t++){

                    innerArray[t][k] = mapatest.getString(k);

                }
            }

see my answer, this way is simple and quick - http://stackoverflow.com/questions/33720204/retrofit-returns-linkedtreemap-instead-of-json/33720542#33720542 — Vladimir Markeev, Nov 17 '15 at 20:55
try to get it with Retrofit (see link above) and you will not parse array — Vladimir Markeev, Nov 17 '15 at 21:16

Marcos Vasconcelos · Answer 1 · 2015-11-17T20:28:25.790

1

While mapObejct.getJSONArray("map") returns an array where each entry is the X of your table, each item of the array will be an Array itself (getJSONArray again) and will be your Y of the table.

The code would looks like:

map = obj.getJSONArray("map);
for(int i = 0; i < map.getCount(); i++){
   innerArray = map.getJSONArray(i);
   for(int k = 0; k < innerArray.getCount(); i++){
      innerItem = map.getString(k);
   }      
}

This will navigate trought i,k where they would be your array[i][k]

EDIT: With your code:

 JSONArray mapatest = mapObject.getJSONArray("map");
        String[][] innerArray = null;

        for(int t = 0; t < mapatest.getCount(); t++){
            JSONArray innerArrayObj = mapatest.getJSONArray(t);
            innerArray[t] = new String[innerArrayObj.getCount());

            for(int k = 0; k < innerArrayObj.getCount(); t++){

                innerArray[t][k] = innerArrayObj.getString(k);

            }
        }

edited Nov 17 '15 at 20:28

answered Nov 17 '15 at 19:25

Marcos Vasconcelos

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I think I am not understanding it, I have this but it doesn't work. Thank you for your help. (I can't post code here, so I'll put it in the question.) – Souloibur Nov 17 '15 at 20:10
Oh.. one miss, check the answer – Marcos Vasconcelos Nov 17 '15 at 20:27
Yes it seems it will work, but I have an error in getCount(). "Cannot resolve method" – Souloibur Nov 17 '15 at 20:48
I've changed "getCount()" to "length()" but now I have this error: E/AndroidRuntime: Caused by: java.lang.NullPointerException: Attempt to write to null array In this line: innerArray[t] = new String[innerArrayObj.length()]; – Souloibur Nov 17 '15 at 21:19
You must add innerArray = new String[mapatest.getCount()][]; before the for – Marcos Vasconcelos Nov 18 '15 at 13:06

Trying to read 2D array from Json to Android

1 Answers1