I was finishing programming a connection to a remote database, but as soon as I hit the app, it loads a few seconds checking the connection and closes the app, I do not know the reasons, I have downloaded several missing libraries and other versions of android and the same error appears
This problem
NullPointerException: lock == null
is related to when you instantiate a InputStreamReader () you use a null value of FileInputStream :
FileInputStream myFileInputStream = null;
InputStreamReader myInputStreamReader = new InputStreamReader(myFileInputStream);
In fact it seems to me that later you try to use JsonParser and that's why you get this message:
JsonException parsing error: End of input at character 0 of
The error is in the way you are processing the response. Before giving it a format or doing some process, check that the result is a string to print it in log .