Android上传图片到服务器，服务端利用.NET WCFRest服务读取文件的解决方案

　　在项目中遇到要将Android设备拍摄的照片上传的服务器，将文件保存在服务器本地的文件夹中，数据库中保存的是图片文件名。整个上传是将图片生成二进制流通过HTTP请求上传到服务端，服务端是基于.NET环境的，采用ashx一般处理程序处理服务返回结果。

　　下面直接贴上代码，先是上传文件HTTP请求的静态方法：

 /**
  * 通过上传文件流形式上传文件
  * @param picPaths
  * @param requestURL
  * @return
  */
  public static String uploadFile(String[] picPaths, String requestURL) {
     String boundary = UUID.randomUUID().toString();
     String prefix = "--", end = "\r\n";
     String content_type = "multipart/form-data"; // 内容类型
     String CHARSET = "utf-8"; // 设置编码
     int TIME_OUT = 10 * 10000000; // 超时时间
     try {
         URL url = new URL(requestURL);
         HttpURLConnection conn = (HttpURLConnection) url.openConnection();
         conn.setReadTimeout(TIME_OUT);
         conn.setConnectTimeout(TIME_OUT);
         conn.setDoInput(true); // 允许输入流
         conn.setDoOutput(true); // 允许输出流
         conn.setUseCaches(false); // 不允许使用缓存
         conn.setRequestMethod("POST"); // 请求方式
         conn.setRequestProperty("Charset", "utf-8"); // 设置编码
         conn.setRequestProperty("connection", "keep-alive");
         conn.setRequestProperty("Content-Type", content_type + ";boundary=" + boundary);
         //当文件不为空，把文件包装并且上传
         OutputStream outputSteam = conn.getOutputStream();
         DataOutputStream dos = new DataOutputStream(outputSteam);

         StringBuffer stringBuffer = new StringBuffer();
         stringBuffer.append(prefix);
         stringBuffer.append(boundary);
         stringBuffer.append(end);
         dos.write(stringBuffer.toString().getBytes());

         dos.writeBytes("Content-Disposition: form-data; name=\"" + author + "\"" + end);
         dos.writeBytes(end);
         dos.writeBytes("klose");
         dos.writeBytes(end);

         for(int i = 0; i < picPaths.length; i++){
             File file = new File(picPaths[i]);
             StringBuffer sb = new StringBuffer();
             sb.append(prefix);
             sb.append(boundary);
             sb.append(end);
             sb.append("Content-Disposition: form-data; name=\"" + i + "\"; filename=\"" + file.getName() + end);
             sb.append("Content-Type: application/octet-stream; charset=" + CHARSET + end);
             sb.append(end);
             dos.write(sb.toString().getBytes());

             InputStream is = new FileInputStream(file);
             byte[] bytes = new byte[8192];//8k
             int len = 0;
             while ((len = is.read(bytes)) != -1) {
                 dos.write(bytes, 0, len);
             }
             is.close();
             dos.write(end.getBytes());//一个文件结束标志
         }
         byte[] end_data = (prefix + boundary + prefix + end).getBytes();//结束 http 流
         dos.write(end_data);
         dos.flush();

         //获取响应状态
         int responseCode = conn.getResponseCode();

         if (HttpURLConnection.HTTP_OK == responseCode) { //连接成功
             //当正确响应时处理数据
             StringBuffer buffer = new StringBuffer();
             String readLine;
             BufferedReader responseReader;
             //处理响应流
             responseReader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
             while ((readLine = responseReader.readLine()) != null) {
                 buffer.append(readLine).append("\n");
             }
             responseReader.close();
             Log.d("HttpPOST", buffer.toString());
             return "保存成功!";//成功
         }
     }catch (Exception e) {
         e.printStackTrace();
     }
     return "保存失败!";
 }

　　二进制流报文格式如下所示：

 --b8690cde-dc7b-48cb-868a-f328b6355a3c
 Content-Disposition: form-data; name="author"

 xxx
 --b8690cde-dc7b-48cb-868a-f328b6355a3c
 Content-Disposition: form-data; name=""; filename="xxxx.jpg"
 Content-Type: application/octet-stream; charset=utf-

 (这里是二进制数据)
 --b8690cde-dc7b-48cb-868a-f328b6355a3c--

　　在.NET服务端接受二进制流的ashx程序代码如下所示：

 /// <summary>
 /// Handler1 的摘要说明
 /// </summary>
 public class Handler1 : IHttpHandler
 {
     string rootPath = ConfigurationManager.AppSettings["FileDirectory"];
     private IRepository _repository = new RepositoryImpl();

     public void ProcessRequest(HttpContext context)
     {

         var request = context.Request;
         returnUploadResult(request);

     }

         public string returnUploadResult(HttpRequest request)
     {
         var files = request.Files;
         var formUpload = request.Files.Count > ;

         string resultStr = "";

         if (formUpload)
         {

             for (int i = ; i < request.Files.Count; i++)
             {
                 var formFilename = formUpload ? request.Files[i].FileName : null;
                 var upload = new FineUpload
                 {
                     Filename = formFilename,
                     InputStream = formUpload ? request.Files[i].InputStream : request.InputStream
                 };
                 string fileName = upload.Filename;
                 string fullFileName = Path.Combine(rootPath, fileName);

                 if (System.IO.File.Exists(fullFileName))
                 {
                     XSBPHOTOURL template = new XSBPHOTOURL();
                     template.NAME = fileName.ToString();
                     template.IMGGUID = Guid.NewGuid().ToString();
                     _repository.Save<XSBPHOTOURL>(template);
                     resultStr += (fullFileName + "已存在。 ");
                 }
                 else
                 {
                     XSBPHOTOURL template = new XSBPHOTOURL();
                     template.NAME = fileName.ToString();
                     template.IMGGUID = Guid.NewGuid().ToString();
                     _repository.Save<XSBPHOTOURL>(template);
                     upload.SaveAs(fullFileName);
                     resultStr += (fullFileName + "保存成功。 ");
                 }
             }
         }
         return resultStr;

     }

     public bool IsReusable
     {
         get
         {
             return false;
         }
     }
 }

　　服务端文件保存路径写在WebConfig中，在appSettings中添加一行代码就可以了，示例如下：

<appSettings>
  <add key="FileDirectory" value="D:/UploadFiles"/>
</appSettings>

　　这样就从Android客户端完成了文件上传功能，欢迎各位批评指正！