我使用了一个
它能正常工作,但有时会遇到需要重新启动服务或服务器才能解决的问题。最初我用以下代码声明了监听器对象:
这里是处理请求的方法:
HttpListener
来编写一个处理异步请求的 Windows 服务。它能正常工作,但有时会遇到需要重新启动服务或服务器才能解决的问题。最初我用以下代码声明了监听器对象:
public HttpListener PointsListener = new HttpListener();
这里是开始监听的方法代码。我从服务的OnStart
方法中调用它:
public string ListenerStart()
{
try
{
if (!PointsListener.IsListening)
{
PointsListener.Prefixes.Add(String.Concat("http://*:", points_port, "/"));
PointsListener.Start();
PointsListener.BeginGetContext(PointProcessRequest, PointsListener);
LogWriter("Http listener activated on port " + points_port);
return "Listener started";
}
else
{
return "Listener is already started!";
}
}
catch (Exception err)
{
LogWriter("Error in LIstenerStart \r\n" + err.ToString());
return ("Error: " + err.Message);
}
}
这里是处理请求的方法:
private void PointProcessRequest(IAsyncResult result)
{
HttpListener listener = (HttpListener)result.AsyncState;
HttpListenerContext context = listener.EndGetContext(result);
HttpListenerRequest request = context.Request;
HttpListenerResponse response = context.Response;
response.KeepAlive = false;
System.IO.Stream output = response.OutputStream;
try
{
//declaring a variable for responce
string responseString = "<html>My Response: request is not allowed by server protocol</html>";
// Commands and actions to set responceString
byte[] buffer = Encoding.UTF8.GetBytes(responseString);
response.ContentLength64 = buffer.Length;
output.Write(buffer, 0, buffer.Length);
}
catch (Exception err)
{
LogWriter("Error in PointProcessRequest: \r\n" + err.ToString());
}
finally
{
try
{
output.Flush();
output.Close();
response.Close();
}
catch (Exception err)
{
LogWriter("Error in PointProcessRequest CLOSING OUTPUT STREAM: \r\n" + err.ToString());
}
finally
{
PointsListener.BeginGetContext(PointProcessRequest, PointsListener);
}
}
}
有时候它能正常工作,但是日志中出现了以下错误:
Error in PointProcessRequest:
System.Net.HttpListenerException: The specified network name is no longer available
в System.Net.HttpResponseStream.Write(Byte[] buffer, Int32 offset, Int32 size)
в ARK_Dealer.ark.PointProcessRequest(IAsyncResult result)
[26.01.2011 9:00:54] Error in PointProcessRequest CLOSING OUTPUT STREAM:
System.InvalidOperationException: Cannot close stream until all bytes are written.
в System.Net.HttpResponseStream.Dispose(Boolean disposing)
в System.IO.Stream.Close()
в ARK_Dealer.ark.PointProcessRequest(IAsyncResult result)
我认为问题出现在某个点向服务器发送请求,但在接收答案之前失去连接。
我该如何防止抛出异常?响应对象是否会自动正确处理?我该如何解决这个问题?