public IAsyncResult Execute(string url, ExecuteListener listener)
{
WebRequest request = null;
try
{
// Create a new webrequest to the mentioned URL.
request = WebRequest.Create(url);
}
catch (Exception e)
{
log.Error(string.Format("Create WebRequest for url [{0}] failed", url), e);
listener.ExecuteCompleted(null, e);
return null;
}
//Callback parameter
RequestStateInfo requestStateInfo = new RequestStateInfo();
requestStateInfo.url = url;
requestStateInfo.request = request;
requestStateInfo.listener = listener;
IAsyncResult asyncResult = null;
try
{
// Start the Asynchronous call for response.
asyncResult = (IAsyncResult)request.BeginGetResponse(new AsyncCallback(RespCallback),
requestStateInfo);
}
catch (Exception e)
{
requestStateInfo.errorMessage = string.Format("Execute for BeginGetResponse [{0}] failed", url);
ExecuteDone(requestStateInfo, e);
}
return asyncResult;
}
private void ExecuteDone(RequestStateInfo requestStateInfo, Exception e)
{
//log the exception if there is one
if(e != null)
{
log.Error(requestStateInfo.errorMessage, e);
}
//close the stream and release the connection
if(requestStateInfo.response != null)
{
CloseQuietly(requestStateInfo.response);
}
//execute the listener
requestStateInfo.listener.ExecuteCompleted(requestStateInfo, e);
}