Trouble on creating a JSON Object on Android

Trouble on creating a JSON Object on Android

I'm having a provblem on creating a JSON object on android app.
I's getting a JSON array like :
[{"estado":"1","longitude":"19.1714172","latitude":"-8.9477729"},{"estado":"1","longitude":"37.1714681","latitude":"-8.9476652"}]
from the server (using a servlet)!
But when i try to access the array objects on a for cicle like:
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
//the rest of code
}
my app gives some error, and simple stop (something like an ANR! i'm not
sure about this).
Can anyone help, please?!