java.sql.SQLException: I/O Error: Socket closed - android-asynctask

Question

I want to sync data from MSSQL to android sqllite.All syncdata method write in ansync class.But sometime application return java.sql.SQLException: I/O Error: Socket closed error and not finish sync data . Sometime application successfully sync all update data.
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
{
CheckProductGroupInfoHasNew();
CheckProductInfoHasNew();
CheckProductPriceInfoHasNew();
CheckCustomerInfoHasNew();
}
private void CheckProductInfoHasNew() {
AsyncSyncData _AsyncSyncData = new AsyncSyncData();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
_AsyncSyncData.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,
"PC");
else
_AsyncSyncData.execute("PC");
}
private void CheckProductPriceInfoHasNew() {
AsyncSyncData _AsyncSyncData = new AsyncSyncData();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
_AsyncSyncData.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,
"PPRICE");
else
_AsyncSyncData.execute("PPRICE");
}
private void CheckCustomerInfoHasNew() {
AsyncSyncData _AsyncSyncData = new AsyncSyncData();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
_AsyncSyncData.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,
"CV");
else
_AsyncSyncData.execute("CV");
}
private void CheckProductGroupInfoHasNew() {
AsyncSyncData _AsyncSyncData = new AsyncSyncData();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
_AsyncSyncData.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,
"PG");
else
_AsyncSyncData.execute("PG");
}
class AsyncSyncData extends AsyncTask<String, String, String> {
#Override
protected String doInBackground(String... params) {
if (params[0].toString().equals("PG")) {
_ListProductGroupInfo = _MSDBConnection
.SelectProductGroupInfo(_Query);}
} else if (params[0].equals("PC")) {
_ListProductInfo = _MSDBConnection
.SelectProductInfo(_Query);
} else if (params[0].equals("CV")) {
_ListCustomerInfo = _MSDBConnection
.SelectCustomerInfo(_Query);
} else if (params[0].equals("PPRICE")) {
_ListProductPriceInfo = _MSDBConnection
.SelectProductPriceInfo(_Query);
} else if (params[0].equals("VAT")) {
_ListCustomerInfo = _MSDBConnection
.SelectCustomerInfo(_Query);
}
#Override
protected void onPostExecute(String result) {
try {
if (result.equals("PG")) {
int _result = 0;
if ((_result = SyncProductGroupInfo()) > 0) {
Toast.makeText(
_context,
"Save Successfully .Product Group Data rows = "
+ _result, Toast.LENGTH_SHORT).show();
}
} else if (result.equals("PC")) {
int _result = 0;
if ((_result = SyncProductInfo()) > 0) {
Toast.makeText(
_context,
"Save Successfully .Product Data rows = "
+ _result, Toast.LENGTH_SHORT).show();
}
} else if (result.equals("PPRICE")) {
int _result = 0;
if ((_result = SyncProductPriceInfo()) > 0) {
Toast.makeText(
_context,
"Save Successfully .Product Price Data rows = "
+ _result, Toast.LENGTH_SHORT).show();
}
} else if (result.equals("CV")) {
int _result = 0;
if ((_result = SyncCustomerInfo()) > 0) {
Toast.makeText(
_context,
"Save Successfully .Customer Data rows = "
+ _result, Toast.LENGTH_SHORT).show();
}
HomeFragment.BindProductGroup();
SyncActivity.this.finish();
// close the progress dialog
progressDialog.dismiss();
} else if (result.equals("VAT")) {
if (SyncVatInfo()) {
Toast.makeText(_context, "Save Successfully Vat Data",
Toast.LENGTH_SHORT).show();
}
SyncActivity.this.finish();
// close the progress dialog
progressDialog.dismiss();
}
} catch (Exception ex) {
Log.i("onPostExecute Ex",
" Chan I'm onPostExecute" + ex.getMessage());
ex.printStackTrace();
Toast.makeText(_context, ex.getMessage().toString(),
Toast.LENGTH_LONG).show();
SyncActivity.this.finish();
// close the progress dialog
progressDialog.dismiss();
} finally {
}
}