HttpWebRequest中GetResponse或者说GetRequestStream偶尔超时,或者是各种操作超时造成的假死的一些解决方案

来源:转载

今天用了将近一天的时间来查找这个问题的存在,不停的百度查找原因测试原因,发现解决方案很是简单,不过最好还好哦啊都解决了,在这里纪录一下,希望可以帮到你们

 payload = System.Text.Encoding.UTF8.GetBytes(postDataStr); request.ContentLength = payload.Length; Stream writer = request.GetRequestStream(); writer.Write(payload, 0, payload.Length); //writer.Flush(); writer.Close(); //HttpWebResponse response = (HttpWebResponse)request.GetResponse(); HttpWebResponse res; try { System.Net.ServicePointManager.DefaultConnectionLimit = 200; res = (HttpWebResponse)request.GetResponse(); } catch (WebException ex) { res = (HttpWebResponse)ex.Response; }

 今天我的res 一直报操作超时,百度了很多方案,一一测试,总结来说,如果你也出现了这种错误,可以一次尝试一下方案

第一种:加长request的timeout的时间,默认是100秒(我就是测试了好多方案,才发现我的timeout的时间太短,引起的操作超时)

第二种:设置request.KeepAlive = false;原因是:默认KeepAlive的属性是true,将此属性设置为 true 以发送带有 Keep-alive 值的 Connection HTTP 标头。 应用程序使用 KeepAlive 指示持久连接的首选项。 当 KeepAlive 属性为 true 时,应用程序与支持它们的服务器建立持久连接。也要记住要及时关闭相对应的关闭工作

if (request != null) { request.Abort(); } if (res != null) { res.Close(); }

第三种:

System.Net.ServicePointManager.DefaultConnectionLimit = 200;

 加上这句话,因为这个默认设置的是2,当http的连接超过2条时,也会报这种操作超时的错误

第四种:

 System.GC.Collect(); HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url); request.Method = "POST"; request.ContentType = "application/x-www-form-urlencoded"; request.ContentLength = postDataStr.Length; request.KeepAlive = false; request.Timeout = 6000000;

 在

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);

 之前加上:System.GC.Collect();

原因是:系统中的http相关的资源没有正确的释放,导致后续的GetResponse或者说GetRequestStream超时死掉

    改进之后的所有代码:

public static bool HttpPost(string Url, string postDataStr, out string errMsg, out string returnData) { try { System.GC.Collect(); HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url); request.Method = "POST"; request.ContentType = "application/x-www-form-urlencoded"; request.ContentLength = postDataStr.Length; request.KeepAlive = false; request.Timeout = 6000000; //StreamWriter writer = new StreamWriter(request.GetRequestStream(), Encoding.UTF8); //writer.Write(postDataStr); //writer.Flush(); byte[] payload; payload = System.Text.Encoding.UTF8.GetBytes(postDataStr); request.ContentLength = payload.Length; Stream writer = request.GetRequestStream(); writer.Write(payload, 0, payload.Length); //writer.Flush(); writer.Close(); //HttpWebResponse response = (HttpWebResponse)request.GetResponse(); HttpWebResponse res; try { System.Net.ServicePointManager.DefaultConnectionLimit = 200; res = (HttpWebResponse)request.GetResponse(); } catch (WebException ex) { res = (HttpWebResponse)ex.Response; } //StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8); StreamReader reader = new StreamReader(res.GetResponseStream(), Encoding.UTF8); string retString = reader.ReadToEnd(); errMsg = ""; try { returnData = Util.base642Str(retString); } catch (Exception) { returnData = retString; //throw; } if (request != null) { request.Abort(); } if (res != null) { res.Close(); } return true; }

                       参考文章:https://www.cnblogs.com/wohexiaocai/p/5673193.html

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