Display name Display name - 2 months ago 23
Android Question

Data inserts to database and then app crashes

I am learning how to send data across to an external database and the code works however it is a little buggy to say the least. I am using this tutorial and a lot of the code has since depreciated so I have been trying to update it myself.

What should happen is when the user hits the sync button the data held in the SQLite database should be sent across to the external database. This happens but then the app crashes. The solution is not clear to me in the log cat and I'm unsure how to rectify the problem. I have managed to isolate the crash to this section of code which was one of the lines of code that was depreciated (on success, on failure).

I have done research on the AsyncHTTPResponseHandler and thought that the code was fine and as I said earlier it does connect to the DB and inserts into the table but then immediately crashes. I have put the code that I think is the problem, along with the log cat.

public void syncSQLiteMySQLDB() {
//Create AsycHttpClient object
AsyncHttpClient client = new AsyncHttpClient();
RequestParams params = new RequestParams();
ArrayList<HashMap<String, String>> userList = controller.getAllUsers();
if (userList.size() != 0) {
if (controller.dbSyncCount() != 0) {
prgDialog.show();
params.put("usersJSON", controller.composeJSONfromSQLite());
client.post("http://jakebreen.co.uk/android/sqlitemysqlsync/inseruser.php", params, new AsyncHttpResponseHandler() {
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] response) {
System.out.println(response);
prgDialog.hide();
try {
JSONArray arr = new JSONArray(response);
System.out.println(arr.length());
for (int i = 0; i < arr.length(); i++) {
JSONObject obj = (JSONObject) arr.get(i);
System.out.println(obj.get("id"));
System.out.println(obj.get("status"));
controller.updateSyncStatus(obj.get("id").toString(), obj.get("status").toString());
}
Toast.makeText(getApplicationContext(), "DB Sync completed!", Toast.LENGTH_LONG).show();
} catch (JSONException e) {
// TODO Auto-generated catch block
Toast.makeText(getApplicationContext(), "Error Occured [Server's JSON response might be invalid]!", Toast.LENGTH_LONG).show();
e.printStackTrace();
}
}

@Override
public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {

// TODO Auto-generated method stub
prgDialog.hide();
if (statusCode == 404) {
Toast.makeText(getApplicationContext(), "Requested resource not found", Toast.LENGTH_LONG).show();
} else if (statusCode == 500) {
Toast.makeText(getApplicationContext(), "Something went wrong at server end", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getApplicationContext(), "Unexpected Error occcured! [Most common Error: Device might not be connected to Internet]", Toast.LENGTH_LONG).show();
}
}
});
} else {
Toast.makeText(getApplicationContext(), "SQLite and Remote MySQL DBs are in Sync!", Toast.LENGTH_LONG).show();
}
} else {
Toast.makeText(getApplicationContext(), "No data in SQLite DB, please do enter User name to perform Sync action", Toast.LENGTH_LONG).show();
}
}


Log cat

--------- beginning of crash
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.year2.sqlitemysqlsync, PID: 2281
java.lang.RuntimeException: java.lang.ClassCastException: java.lang.Byte cannot be cast to org.json.JSONArray
at com.loopj.android.http.AsyncHttpResponseHandler.onUserException(AsyncHttpResponseHandler.java:304)
at com.loopj.android.http.AsyncHttpResponseHandler.handleMessage(AsyncHttpResponseHandler.java:395)
at com.loopj.android.http.AsyncHttpResponseHandler$ResponderHandler.handleMessage(AsyncHttpResponseHandler.java:510)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
Caused by: java.lang.ClassCastException: java.lang.Byte cannot be cast to org.json.JSONArray
at com.year2.sqlitemysqlsync.MainActivity$1.onSuccess(MainActivity.java:102)
at com.loopj.android.http.AsyncHttpResponseHandler.handleMessage(AsyncHttpResponseHandler.java:351)
at com.loopj.android.http.AsyncHttpResponseHandler$ResponderHandler.handleMessage(AsyncHttpResponseHandler.java:510) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5254) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 
Application terminated.

Answer

Instead of

JSONArray arr = new JSONArray(response);

try

JSONArray arr = new JSONArray(new String(response));