android上传图片到服务器，求服务器那边和android的Activity的完整代码。

服务器端servlet代码：
public void doPost(HttpServletRequest request, HttpServletResponse response)
?? throws ServletException, IOException {

?? //获取输入流，是HTTP协议中的实体内容
??? ServletInputStream? sis=request.getInputStream();
???
???? File file = new File(request.getSession().getServletContext().getRealPath("/img/"),"img_"+0+".jpg");
???? for (int imgnum = 0;file.exists();imgnum++)
???? {
????? file? = new File(request.getSession().getServletContext().getRealPath("/img/"),"img_"+imgnum+".jpg");
???? }
????????? //缓冲区
????????? byte buffer[]=new byte[1024];
????????? FileOutputStream fos=new FileOutputStream(file);
????????? int len=sis.read(buffer, 0, 1024);
????????? //把流里的信息循环读入到文件中
????????? while( len!=-1 )
????????? {
????????????? fos.write(buffer, 0, len);
????????????? len=sis.readLine(buffer, 0, 1024);
????????? }
????????? fos.close();
????????? sis.close();
}


android客户端代码：
public static void uploadFile(String imageFilePath)
??? {
????? String actionUrl = "http://192.168.1.32:8080/UploadServer/ImageServlet";
????? try
????? {
??????? URL url =new URL(actionUrl);
??????? HttpURLConnection con=(HttpURLConnection)url.openConnection();
??????
??????? con.setDoInput(true);
??????? con.setDoOutput(true);
??????? con.setUseCaches(false);
??????
??????? con.setRequestMethod("POST");
??????
??????
??????? DataOutputStream ds =? new DataOutputStream(con.getOutputStream());
??????? File file = new File(imageFilePath);
??????
??????? FileInputStream fStream = new FileInputStream(file);
??????? int bufferSize = 1024;
??????? byte[] buffer = new byte[bufferSize];

??????? int length = -1;
??????
??????? while((length = fStream.read(buffer)) != -1)
??????? {
????????
????????? ds.write(buffer, 0, length);
??????? }

??????
??????? fStream.close();
??????? ds.flush();
??????
??????
??????? InputStream is = con.getInputStream();
??????? int ch;
??????? StringBuffer b =new StringBuffer();
??????? while( ( ch = is.read() ) != -1 )
??????? {
????????? b.append( (char)ch );
??????? }
??????
??????
??????? ds.close();
????? }
????? catch(Exception e)
????? {
?????? e.printStackTrace();
????? }
????
??? }