Network Connection Failed after 10 minutes on blackberry - blackberry

Question

I've implemented timer task on background application.
I've collected current lat and long. and send to server each 30 seconds.
I've used below code to send the information to server. It sends successfully..
My problem is, after i've checked 10 minutes, I'm unable to send. it throws a No Network error. I've checked browser too but no network.
If reset the device, its working again well. But the same problem occurs after 5 or 10 mins.
How to resolve this?
My code is,
try
{
StreamConnection connection = (StreamConnection) Connector.open(url+suffix);
((HttpConnection) connection).setRequestMethod(HttpConnection.GET);
int responseCode = ((HttpConnection) connection).getResponseCode();
if (responseCode != HttpConnection.HTTP_OK) {
showDialog("Unexpected response code :"+ responseCode);
connection.close();
return;
}
((HttpConnection) connection).getHeaderField("Content-type");
ByteArrayOutputStream baos = new ByteArrayOutputStream();
InputStream responseData = connection.openInputStream();
byte[] buffer = new byte[1000];
int bytesRead = responseData.read(buffer);
while (bytesRead > 0) {
baos.write(buffer, 0, bytesRead);
bytesRead = responseData.read(buffer);
}
baos.close();
connection.close();
String s = new String(baos.toByteArray());
showDialog("Responce from server "+s);
}
catch (IOException e)
{
}

Answer 1

Usually, when you have some problem where it works a few times, and then stops working, and you need to reset the device, you've done something that has used up all available resources, without releasing them when you're done.
When performing repeated network operations, you should clean up your streams and connections after each use.
Normally, the proper way to write network code is to declare network variables outside a try block, assign and use them inside the try, while catching any IOExceptions thrown. Then, you use a finally block to clean up your resources, no matter whether the code finished successfully or not.
I'll also note that when debugging network problems, you don't want to have a catch() handler that simply traps exceptions and does nothing with them. Print out a message to the console (for testing) or log the error to a file.
Finally, I can't see your showDialog() method, but if it's displaying a UI to the user/tester, you need to do that on the UI thread. But, the network code that you show above should be run on a background thread to keep the UI responsive. So, inside showDialog(), just make sure you use code to modify the UI on the UI thread.
So, a better implementation might be this:
private void requestFromServer() {
StreamConnection connection = null;
ByteArrayOutputStream baos = null;
InputStream responseData = null;
try
{
connection = (StreamConnection) Connector.open(url+suffix);
((HttpConnection) connection).setRequestMethod(HttpConnection.GET);
int responseCode = ((HttpConnection) connection).getResponseCode();
if (responseCode != HttpConnection.HTTP_OK) {
showDialog("Unexpected response code :"+ responseCode);
return;
}
((HttpConnection) connection).getHeaderField("Content-type");
baos = new ByteArrayOutputStream();
responseData = connection.openInputStream();
byte[] buffer = new byte[1000];
int bytesRead = responseData.read(buffer);
while (bytesRead > 0) {
baos.write(buffer, 0, bytesRead);
bytesRead = responseData.read(buffer);
}
String s = new String(baos.toByteArray());
showDialog("Responce from server "+s);
}
catch (IOException e)
{
System.out.println("Network error: " + e.getMessage());
}
finally
{
try {
if (connection != null) {
connection.close();
}
if (baos != null) {
baos.close();
}
if (responseData != null) {
responseData.close();
}
} catch (IOException e) {
// nothing to do here
}
}
}
private void showDialog(final String msg) {
UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run() {
Dialog.alert(msg);
}
});
}