java类访问一个网络URL,获取压缩格式的下载文件

/** *url:访问的网络地址 *paramData：需要提交的参数 *sFilePath  :访问网络地址后下载到本地的路径 c:/test.txt * */ public void downLoadFiletoLocal(String sFilePath, String paramData, URL url) {  try {   URLConnection conn = url.openConnection();   conn.setDoOutput(true);   //发送域信息   OutputStreamWriter outwr = new OutputStreamWriter(conn.getOutputStream());   outwr.write(paramData);//这里组织域信息   outwr.flush();   outwr.close();   //获取返回数据   InputStream in = conn.getInputStream();   int n = 0;   byte[] buf = new byte[4 * 1024];   FileOutputStream out = new FileOutputStream(new File(sFilePath));   while ((n = in.read(buf, 0, buf.length)) != -1) {    out.write(buf, 0, n);   }   out.close();   in.close();  } catch (IOException e) {   e.printStackTrace();  } }