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C#以post方式调用struts rest-plugin service的问题
struts2: 玩转 rest-plugin 一文中，学习了用struts2开发restful service的方法，发现用c#以post方式调用时各种报错，但java、ajax，包括firefox 的rest client插件测试也无问题。
先给出rest service中的这个方法：
1 // POST /orders 2 public HttpHeaders create() throws IOException, ServletException { 3 ordersService.doSave(model); 4 HttpServletResponse response = ServletActionContext.getResponse(); 5 HttpServletRequest request = ServletActionContext.getRequest(); 6 String ContentType = request.getHeader("Content-Type").toLowerCase(); 7 if (ContentType.startsWith("application/xml")) { // 返回xml视图 8 response.sendRedirect("orders/" + model.getId() + ".xml"); 9 } else if (ContentType.startsWith("application/json")) { // 返回json视图10 response.sendRedirect("orders/" + model.getId() + ".json");11 } else {// 返回xhtml页面视图12 response.sendRedirect("orders/");13 }14 return null;15 }
代码不复杂，post一段String过来(xml/json/html格式均可)，自动映射成Order对象的实例model，然后根据请求HttpHeader中的Content-Type，如果是xml(application/xml)，则返回model对应的xml，如果是json(application/json)，则返回model对应的json，其它则返回页面
c#的调用代码：
1 static string PostDataByWebClient(String postUrl, String paramData, String mediaType) 2 { 3 String result = String.Empty; 4 try 5 { 6 byte[] postData =http://www.mamicode.com/ Encoding.UTF8.GetBytes(paramData); 7 WebClient webClient = new WebClient(); 8 webClient.Headers.Add("Content-Type", mediaType); 9 byte[] responseData = http://www.mamicode.com/webClient.UploadData(new Uri(postUrl), "POST", postData);10 result = Encoding.UTF8.GetString(responseData);11 }12 catch (Exception e)13 {14 Console.WriteLine(e);15 result = e.Message;16 }17 return result;18 }19 20 static string PostDataByWebRequest(string postUrl, string paramData, String mediaType)21 {22 string result = string.Empty;23 Stream newStream = null;24 StreamReader sr = null;25 HttpWebResponse response = null;26 try27 {28 byte[] byteArray = Encoding.UTF8.GetBytes(paramData);29 HttpWebRequest webReq = (HttpWebRequest)WebRequest.Create(new Uri(postUrl));30 webReq.Method = "POST";31 webReq.ContentType = mediaType;32 webReq.ContentLength = byteArray.Length;33 newStream = webReq.GetRequestStream();34 newStream.Write(byteArray, 0, byteArray.Length);35 response = (HttpWebResponse)webReq.GetResponse();36 sr = new StreamReader(response.GetResponseStream(), Encoding.UTF8);37 result = sr.ReadToEnd();38 }39 catch (Exception ex)40 {41 Console.WriteLine(ex);42 result = ex.Message;43 }44 finally45 {46 if (sr != null)47 {48 sr.Close();49 }50 if (response != null)51 {52 response.Close();53 }54 if (newStream != null)55 {56 newStream.Close();57 }58 }59 return result;60 }
这二种常用的调用方式，居然全跪了，返回的结果是一堆java异常：
java.lang.NullPointerException
at org.apache.struts2.convention.ConventionUnknownHandler.handleUnknownActionMethod(ConventionUnknownHandler.java:423)
at com.opensymphony.xwork2.DefaultUnknownHandlerManager.handleUnknownMethod(DefaultUnknownHandlerManager.java:96)
...
无奈百度了一圈，发现还有另一种方法，利用TcpClient调用
1 static string PostDataByTcpClient(string postUrl, string paramData, String mediaType) 2 { 3 String result = String.Empty; 4 TcpClient clientSocket = null; 5 Stream readStream = null; 6 try 7 { 8 clientSocket = new TcpClient(); 9 Uri URI = new Uri(postUrl);10 clientSocket.Connect(URI.Host, URI.Port);11 StringBuilder RequestHeaders = new StringBuilder();//用来保存HTML协议头部信息12 RequestHeaders.AppendFormat("{0} {1} HTTP/1.1\r\n", "POST", URI.PathAndQuery);13 RequestHeaders.AppendFormat("Connection:close\r\n");14 RequestHeaders.AppendFormat("Host:{0}\r\n", URI.Host);15 RequestHeaders.AppendFormat("Content-Type:{0}\r\n",mediaType);16 RequestHeaders.AppendFormat("\r\n");17 RequestHeaders.Append(paramData + "\r\n");18 Encoding encoding = Encoding.UTF8;19 byte[] request = encoding.GetBytes(RequestHeaders.ToString());20 clientSocket.Client.Send(request);21 readStream = clientSocket.GetStream();22 StreamReader sr = new StreamReader(readStream, Encoding.UTF8);23 result = sr.ReadToEnd();24 }25 catch (Exception e)26 {27 Console.WriteLine(e);28 result = e.Message;29 }30 finally31 {32 if (readStream != null)33 {34 readStream.Close();35 }36 if (clientSocket != null)37 {38 clientSocket.Close();39 }40 }41 return result;42 }
总算调用成功了，但是由于java端是用SendRedirect在客户端重定向的，所以该方法得到的返回结果如下：
HTTP/1.1 302 Found
Server: Apache-Coyote/1.1
Location: http://localhost/struts2-rest-ex/rest/orders/230.xml
Content-Length: 0
Date: Mon, 27 Oct 2014 03:18:56 GMT
Connection: close
是一堆http头的原文，只能曲线救国，将其中的Location:后的部分（即重定向的url），取出来再次get请求，这里还有一个坑，该url返回时，把port弄丢了，正确的重定向url应该是：
http://localhost:8080/struts2-rest-ex/rest/orders/230.xml
手动把端口拼上，再次get，总算返回正确了
C#以post方式调用struts rest-plugin service的问题