關於android上的HttpURLConnections的問題。 （cast-URLConnection，url.openConnection，getOutPutStream（）..）

Question

我有一個關於創建httpurlconnection（或httpsurlconnection）的問題。實際上這是關於在投射url.openconnection之後設置連接標頭。在運行相同代碼之前，現在不運行。我無法理解。 （例外：已經連接...或者像..）

有時它運行到httpConn.getOutPutStream（）;此時它給出錯誤「java.net.ProtocolException：OutputStream不可用，因爲請求標頭已經發送！」

我的錯在哪裏？

之前我使用的代碼：所有代碼是here（我有一個問題關於This Code，太）

URL url = new URL(getUrl()); 
URLConnection conn = url.openConnection(); 
HttpURLConnection httpConn=(HttpURLConnection)conn; /*or HttpsURLConnection*/ 
httpConn.set... 
... 
httpConn.connect(); 
... 

我嘗試鑄造後設置一些設置，但結果是一樣的。 conn.set ..的在工作，但鑄造我不能設置任何後...

改變的代碼：

 URL url = new URL(getUrl()); 
     conn = url.openConnection(); 
     conn.setAllowUserInteraction(false); 
     conn.setConnectTimeout(10000); 
     conn.setRequestProperty("Accept-Charset", "utf-8"); 
     conn.setRequestProperty("Content-Type", 
       "text/xml; charset=utf-8"); 
     conn.setRequestProperty("SOAPAction", 
       "http://tempuri.org/IAuthenticationServiceNew/Authenticate"); 
     conn.setRequestProperty("Software-Version", AppData.VERSION); 
     conn.setDoOutput(true); 
     httpConn = (HttpsURLConnection) conn; 
     httpConn.setChunkedStreamingMode(getParams().getBytes("UTF8").length); 
     httpConn.setInstanceFollowRedirects(true); 

     httpConn.connect(); 
     os = httpConn.getOutputStream(); 
     os.write(getParams().getBytes("UTF8")); 

Answer 1

這是正確的！
「httpConn.setInstanceFollowRedirects（true）」連接標題並將其發送到服務器。我關閉了這段代碼。

 URL url = new URL(getUrl()); 
     httpConn = (HttpURLConnection) url.openConnection(); 
     httpConn.setDoInput(true); 
     httpConn.setDoOutput(true); 
     httpConn.setAllowUserInteraction(false); 
     httpConn.setUseCaches(false); 
     httpConn.setConnectTimeout(10000); 
     httpConn.setRequestProperty("Accept-Charset", "utf-8"); 
     httpConn.setRequestProperty("Content-Type", 
       "text/xml; charset=utf-8"); 
     httpConn.setRequestProperty("SOAPAction", 
       "http://tempuri.org/IAuthenticationServiceNew/" 
         + conTypeString); 
     httpConn.setRequestProperty("Software-Version", AppData.VERSION); 
     httpConn.setRequestMethod("POST"); 
     httpConn.setChunkedStreamingMode(0); 
     os = httpConn.getOutputStream(); 
     os.write(getParams().getBytes("UTF8"));