getting integer from JSON data in java

Question

I try to get Integers from JSON data. But whenever the method gets called, I get the error:

Undeterminated object at character 16 of {"lat": 47175650

This is my JSON data: [{"lat": 47175650, "lon": 7637853}]

And here's my code to read the data. It's for an Android app an it gets the data from a file, puts all the objects from the JSON array into a string array and should create as many GeoPoints as there are objects:

public void loadData(){
    File f = new File("/data/data/com.example.app/files/file.txt");
    if (f.exists()) {
        String locations = null;
        try {
            FileInputStream loadLoc = openFileInput("file.txt");
            List<Byte> data = new ArrayList<Byte>();

            while (true) {
                int b = loadLoc.read();
                if (b == -1)
                    break; // end of file
                else
                    data.add((byte) b);
            }

            // bytes to string
            byte[] bytes = new byte[data.size()];
            for (int i = 0; i<bytes.length; i++) 
                bytes[i] = data.get(i);
            locations = new String(bytes);
            Log.e("debug", locations);
            loadLoc.close();
        } catch (Exception ex) {
            Log.e("debug", ex.getMessage());
        }

        locations = locations.substring(1, locations.length()-1);
        String[] points = locations.split(",");

        JSONObject json;
        GeoPoint p;
        try {
            for (int i=0; i<points.length; i++) {
                json = new JSONObject(points[i]);
                // I guess the "getInt()"s here are the problem
                p = new GeoPoint(json.getInt("lat"), json.getInt("lon"));
                overlay.addItem(p, "location", "location");
            }
        } catch (JSONException ex) {
            Log.e("debug", ex.getMessage());
        }
    }
}

My guess is that I have to put the numbers in quotes, but I have to safe the data in that format (without the integers in quotes) and I know my data is valid JSON.

None really. I just get the "Undeterminated object" error message in LogCat with a "debug" tag. The app doesn't crash. — Quetsalkoatl
– Quetsalkoatl, Commented Nov 1, 2014 at 14:37

Quetsalkoatl · Accepted Answer · 2014-11-01 17:53:14Z

1

You are splitting your JSONObject. Hence [{"lat": 47175650, "lon": 7637853}] becomes two Strings {"lat": 47175650 and "lon": 7637853}.

It appears your data is stored as a JSONArray. Hence, replace

locations = locations.substring(1, locations.length()-1);
String[] points = locations.split(",");

JSONObject json;
GeoPoint p;
try {
    for (int i=0; i<points.length; i++) {
        json = new JSONObject(points[i]);
        // I guess the "getInt()"s here are the problem
        p = new GeoPoint(json.getInt("lat"), json.getInt("lon"));
        overlay.addItem(p, "location", "location");
    }
} catch (JSONException ex) {
    Log.e("debug", ex.getMessage());
}

with

try {
    JSONArray array = new JSONArray(locations);
    for(int i = 0; i < array.length(); i++) {
        JSONObject json = array.getJSONObject(i);
        GeoPoint p = new GeoPoint(json.getInt("lat"), json.getInt("lon"));
        overlay.addItem(p, "location", "location");
    }
} catch (JSONException ex) {
    Log.e("debug", ex.getMessage());
}

edited Nov 1, 2014 at 17:53

Quetsalkoatl

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answered Nov 1, 2014 at 14:40

unchosen

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3 Comments

Quetsalkoatl Over a year ago

Holy cow, your're right i messed it up with split(). How did I miss that! And I didn't know about JSONArray...

Quetsalkoatl Over a year ago

For me the 4th line needs to be "JSONObject obj = array.getJSONObject(i);"

Quetsalkoatl Over a year ago

Two more things: the JSONArray needs to be set inside of the try/catch and there is one } too much. Otherwise THANKS, it worked! (:

mgXD-2 · Accepted Answer · 2014-11-01 14:34:43Z

0

Hace you tried reading it as a string and then cast it to an integer? I mean:

p = new GeoPoint(Integer.valueOf(json.getString("lat")), Integer.valueOf( json.getString("lon")));

answered Nov 1, 2014 at 14:34

mgXD-2

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Comments

hgoebl · Accepted Answer · 2014-11-01 14:42:16Z

0

You should parse the JSON-String as a JSONArray first.

JSONArray points = new JSONArray(locations);
int length = points.length();
for (int i = 0; i < length; ++i) {
    JSONObject point = points.getJSONObject(i);
    int lat = point.getInt("lat");
    int lon = point.getInt("lon");
}

answered Nov 1, 2014 at 14:42

hgoebl

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